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Sample records for 1a2 1b1 2a6

  1. Association between CYP1A2 and CYP1B1 Polymorphisms and Colorectal Cancer Risk: A Meta-Analysis

    PubMed Central

    Liu, Zhi-Zhong; Xie, Jian-Jun; Wang, Wei; Du, Ya-Ping; Chen, Yu; Si, Hui-Qiang; Liu, Qing; Wu, Li-Xia; Wei, Wu

    2014-01-01

    Background The previous published data on the association between CYP1A2*F (rs762551), CYP1B1 Leu432Val (rs1056836), Asn453Ser (rs180040), and Arg48Gly (rs10012) polymorphisms and colorectal cancer risk remained controversial. Methodology/Principal Findings The purpose of this study is to evaluate the role of CYP1A2*F, CYP1B1 Leu432Val, Asn453Ser, and Arg48Gly genotypes in colorectal cancer susceptibility. We performed a meta-analysis on all the eligible studies that provided 5,817 cases and 6,544 controls for CYP1A2*F (from 13 studies), 9219 cases and 10406 controls for CYP1B1 Leu432Val (from 12 studies), 6840 cases and 7761 controls for CYP1B1 Asn453Ser (from 8 studies), and 4302 cases and 4791 controls for CYP1B1Arg48Gly (from 6 studies). Overall, no significant association was found between CYP1A2*F, CYP1B1 Leu432Val, Asn453Ser, and Arg48Gly and colorectal cancer risk when all the eligible studies were pooled into the meta-analysis. And in the subgroup by ethnicity and source of controls, no evidence of significant association was observed in any subgroup analysis. Conclusions/Significance In summary, this meta-analysis indicates that CYP1A2*F, CYP1B1 Leu432Val, Asn453Ser, and Arg48Gly polymorphisms do not support an association with colorectal cancer, and further studies are needed to investigate the association. In addition, our work also points out the importance of new studies for CYP1A2*F polymorphism in Asians, because high heterogeneity was found (dominant model: I2 = 81.3%; heterozygote model: I2 = 79.0). PMID:25115775

  2. HIV protease inhibitors are substrates for OATP1A2, OATP1B1 and OATP1B3 and lopinavir plasma concentrations are influenced by SLCO1B1 polymorphisms

    PubMed Central

    Hartkoorn, Ruben C; San Kwan, Wai; Shallcross, Victoria; Chaikan, Ammara; Liptrott, Neill; Egan, Deirdre; Enrique Salcedo Sora, J; James, Chloe E; Gibbons, Sara; Bray, Pat G; Back, David J; Khoo, Saye H; Owen, Andrew

    2016-01-01

    OATP1B1 and OATP1B3 are major hepatic drug transporters whilst OATP1A2 is mainly located in the brain but is also located in liver and several other organs. These transporters affect the distribution and clearance of many endo- and xenobiotics and have been reported to have functional SNPs. We have assessed the substrate specificites of these transporters for a panel of antiretrovirals and investigated the effects of SNPs within these transporters on the pharmacokinetics of lopinavir. SLCO1A2, SLCO1B1 and SLCO1B3 were cloned, verified and used to generate cRNA for use in the Xenopus laevis oocyte transport system. Using the oocyte system, antiretrovirals were tested for their substrate specificities. Plasma samples (n=349) from the Liverpool therapeutic drug monitoring registry were genotyped for SNPs in SLCO1A2, SLCO1B1 and SLCO1B3 and associations between SNPs and lopinavir plasma concentrations were analysed. Antiretroviral protease inhibitors, but not non-nucleoside reverse transcriptase inhibitors are substrates for OATP1A2, OATP1B1 and OATP1B3. Furthermore, ritonavir was not an inhibitor of OATP1B1. The 521T>C polymorphism in SLCO1B1 was significantly associated with higher lopinavir plasma concentrations. No associations were observed with functional variants of SLCO1A2 and SLCO1B3. These data add to our understanding of the factors that contribute to variability in plasma concentrations of protease inhibitors. Further studies are now required to confirm the association of SLCO1B1 521T>C with lopinavir plasma concentrations and to assess the influence of other polymorphisms in the SLCO family. PMID:20051929

  3. Binding of diverse environmental chemicals with human cytochromes P450 2A13, 2A6, and 1B1 and enzyme inhibition.

    PubMed

    Shimada, Tsutomu; Kim, Donghak; Murayama, Norie; Tanaka, Katsuhiro; Takenaka, Shigeo; Nagy, Leslie D; Folkman, Lindsay M; Foroozesh, Maryam K; Komori, Masayuki; Yamazaki, Hiroshi; Guengerich, F Peter

    2013-04-15

    A total of 68 chemicals including derivatives of naphthalene, phenanthrene, fluoranthene, pyrene, biphenyl, and flavone were examined for their abilities to interact with human P450s 2A13 and 2A6. Fifty-one of these 68 chemicals induced stronger Type I binding spectra (iron low- to high-spin state shift) with P450 2A13 than those seen with P450 2A6, i.e., the spectral binding intensities (ΔAmax/Ks ratio) determined with these chemicals were always higher for P450 2A13. In addition, benzo[c]phenanthrene, fluoranthene, 2,3-dihydroxy-2,3-dihydrofluoranthene, pyrene, 1-hydroxypyrene, 1-nitropyrene, 1-acetylpyrene, 2-acetylpyrene, 2,5,2',5'-tetrachlorobiphenyl, 7-hydroxyflavone, chrysin, and galangin were found to induce a Type I spectral change only with P450 2A13. Coumarin 7-hydroxylation, catalyzed by P450 2A13, was strongly inhibited by 2'-methoxy-5,7-dihydroxyflavone, 2-ethynylnaphthalene, 2'-methoxyflavone, 2-naphththalene propargyl ether, acenaphthene, acenaphthylene, naphthalene, 1-acetylpyrene, flavanone, chrysin, 3-ethynylphenanthrene, flavone, and 7-hydroxyflavone; these chemicals induced Type I spectral changes with low Ks values. On the basis of the intensities of the spectral changes and inhibition of P450 2A13, we classified the 68 chemicals into eight groups based on the order of affinities for these chemicals and inhibition of P450 2A13. The metabolism of chemicals by P450 2A13 during the assays explained why some of the chemicals that bound well were poor inhibitors of P450 2A13. Finally, we compared the 68 chemicals for their abilities to induce Type I spectral changes of P450 2A13 with the Reverse Type I binding spectra observed with P450 1B1: 45 chemicals interacted with both P450s 2A13 and 1B1, indicating that the two enzymes have some similarty of structural features regarding these chemicals. Molecular docking analyses suggest similarities at the active sites of these P450 enzymes. These results indicate that P450 2A13, as well as Family 1 P450

  4. Binding of Diverse Environmental Chemicals with Human Cytochromes P450 2A13, 2A6, and 1B1 and Enzyme Inhibition

    PubMed Central

    Shimada, Tsutomu; Kim, Donghak; Murayama, Norie; Tanaka, Katsuhiro; Takenaka, Shigeo; Nagy, Leslie D.; Folkman, Lindsay M.; Foroozesh, Maryam K.; Komori, Masayuki; Yamazaki, Hiroshi; Guengerich, F. Peter

    2014-01-01

    A total of 68 chemicals including derivatives of naphthalene, phenanthrene, fluoranthene, pyrene, biphenyl, and flavone were examined for their abilities to interact with human P450s 2A13 and 2A6. Fifty-one of these 68 chemicals induced stronger Type I binding spectra (iron low- to high-spin state shift) with P450 2A13 than those seen with P450 2A6, i.e. the spectral binding intensities (ΔAmax/Ks ratio) determined with these chemicals were always higher for P450 2A13. In addition, benzo[c]phenanthrene, fluoranthene, 2,3-dihydroxy-2,3-dihydrofluoranthene, pyrene, 1-hydroxypyrene, 1-nitropyrene, 1-acetylpyrene, 2-acetylpyrene, 2,5,2’,5’-tetrachlorobiphenyl, 7-hydroxyflavone, chrysin, and galangin were found to induce a Type I spectral change only with P450 2A13. Coumarin 7-hydroxylation, catalyzed by P450 2A13, was strongly inhibited by 2’-methoxy-5,7-dihydroxyflavone, 2-ethynylnaphthalene, 2’-methoxyflavone, 2-naphththalene propargyl ether, acenaphthene, acenaphthylene, naphthalene, 1-acetylpyrene, flavanone, chrysin, 3-ethynylphenanthrene, flavone, and 7-hydroxyflavone; these chemicals induced Type I spectral changes with low Ks values. On the basis of the intensities of the spectral changes and inhibition of P450 2A13, we classified the 68 chemicals into eight groups based on the order of affinities for these chemicals and inhibition of P450 2A13. The metabolism of chemicals by P450 2A13 during the assays explained why some of the chemicals that bound well were poor inhibitors of P450 2A13. Finally, we compared the 68 chemicals for their abilities to induce Type I spectral changes of P450 2A13 with the Reverse Type I binding spectra observed with P450 1B1: 45 chemicals interacted with both P450s 2A13 and 1B1, indicating that the two enzymes have some similarty of structural features regarding these chemicals. Molecular docking analyses suggest similarities at the active sites of these P450 enzymes. These results indicate that P450 2A13, as well as Family

  5. Molecular Cloning, Tissue Distribution, and Functional Characterization of Marmoset Cytochrome P450 1A1, 1A2, and 1B1.

    PubMed

    Uehara, Shotaro; Uno, Yasuhiro; Inoue, Takashi; Sasaki, Erika; Yamazaki, Hiroshi

    2016-01-01

    The common marmoset (Callithrix jacchus), a New World monkey, has potential to be an animal model for drug metabolism studies. In this study, we identified and characterized cytochrome P450 (P450) 1A1 and 1B1 in addition to the known P450 1A2 in marmosets. Marmoset P450 1A1 and 1B1 cDNA contained open reading frames encoding 512 and 543 amino acids, respectively, with high sequence identities (90%-93%) to other primate P450 1A1s and 1B1s. A phylogenetic tree based on amino acid sequences showed close evolutionary relationships among marmoset, macaque, and human P450 1A and 1B enzymes. By mRNA quantification and immunoblot analyses in five marmoset tissues, P450 1A1 was mainly expressed in lungs and small intestines, and P450 1A2 was expressed predominantly in livers. In contrast, P450 1B1 was expressed in all tissues tested. Marmoset P450 1A1, 1A2, and 1B1 heterologously expressed in Escherichia coli catalyzed 7-ethoxyresorufin O-deethylation, 7-ethoxycoumarin O-deethylation, and phenacetin O-deethylation, similar to those of humans and cynomolgus monkeys. Notably, marmoset P450 1A1 and 1A2 more efficiently catalyzed 7-ethoxyresorufin O-deethylation than those of the human homologs, but were comparable to those of the cynomolgus monkey homologs. Additionally, marmoset P450 1B1 preferentially catalyzed estradiol 4-hydroxylation; however, rat P450 1B1 more favorably catalyzed estradiol 2-hydroxylation, indicating that the estradiol hydroxylation specificity of marmoset P450 1B1 was similar to those of human and cynomolgus monkey P450 1B1. These results indicated that marmoset P450 1A and 1B enzymes had functional characteristics similar to those of humans and cynomolgus monkeys, suggesting that P450 1A and 1B-dependent metabolism was similar among marmosets, cynomolgus monkeys, and humans.

  6. Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss.

    PubMed

    Saijo, Y; Sata, F; Yamada, H; Suzuki, K; Sasaki, S; Kondo, T; Gong, Y Y; Kato, E H; Shimada, S; Morikawa, M; Minakami, H; Kishi, R

    2004-10-01

    The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.

  7. Pyranoflavones: A Group of Small-molecule Probes for Exploring the Active Site Cavities of Cytochrome P450 Enzymes 1A1, 1A2, and 1B1

    PubMed Central

    Liu, Jiawang; Taylor, Shannon F.; Dupart, Patrick S.; Arnold, Corey L.; Sridhar, Jayalakshmi; Jiang, Quan; Wang, Yuji; Skripnikova, Elena V.; Zhao, Ming; Foroozesh, Maryam

    2013-01-01

    Selective inhibition of P450 enzymes is the key to block the conversion of environmental procarcinogens to their carcinogenic metabolites in both animals and humans. To discover highly potent and selective inhibitors of P450s 1A1, 1A2, and 1B1, as well as to investigate active site cavities of these enzymes, 14 novel flavone derivatives were prepared as chemical probes. Fluorimetric enzyme inhibition assays were used to determine the inhibitory activities of these probes towards P450s 1A1, 1A2, 1B1, 2A6, and 2B1. A highly selective P450 1B1 inhibitor, 5-hydroxy-4′-propargyloxyflavone (5H4′FPE) was discovered. Some tested compounds also showed selectivity between P450s 1A1 and 1A2. Alpha-naphthoflavone-like and 5-hydroxyflavone derivatives preferentially inhibited P450 1A2, while beta-naphthoflavone-like flavone derivatives showed selective inhibition of P450 1A1. On the basis of structural analysis, the active site cavity models of P450 enzymes 1A1 and 1A2 were generated, demonstrating a planar long strip cavity and a planar triangular cavity, respectively. PMID:23600958

  8. Discovery of Western European R1b1a2 Y chromosome variants in 1000 genomes project data: an online community approach.

    PubMed

    Rocca, Richard A; Magoon, Gregory; Reynolds, David F; Krahn, Thomas; Tilroe, Vincent O; Op den Velde Boots, Peter M; Grierson, Andrew J

    2012-01-01

    The authors have used an online community approach, and tools that were readily available via the Internet, to discover genealogically and therefore phylogenetically relevant Y-chromosome polymorphisms within core haplogroup R1b1a2-L11/S127 (rs9786076). Presented here is the analysis of 135 unrelated L11 derived samples from the 1000 Genomes Project. We were able to discover new variants and build a much more complex phylogenetic relationship for L11 sub-clades. Many of the variants were further validated using PCR amplification and Sanger sequencing. The identification of these new variants will help further the understanding of population history including patrilineal migrations in Western and Central Europe where R1b1a2 is the most frequent haplogroup. The fine-grained phylogenetic tree we present here will also help to refine historical genetic dating studies. Our findings demonstrate the power of citizen science for analysis of whole genome sequence data.

  9. Enzymatic characterization of in vitro-expressed Baikal seal cytochrome P450 (CYP) 1A1, 1A2, and 1B1: implication of low metabolic potential of CYP1A2 uniquely evolved in aquatic mammals.

    PubMed

    Iwata, Hisato; Yamaguchi, Keisuke; Takeshita, Yoko; Kubota, Akira; Hirakawa, Shusaku; Isobe, Tomohiko; Hirano, Masashi; Kim, Eun-Young

    2015-05-01

    This study aimed to elucidate the catalytic function of cytochrome P450 (CYP) 1 enzymes in aquatic mammals. Alkoxyresorufin O-dealkylation (AROD) activities including methoxy- (MROD), ethoxy- (EROD), pentoxy- (PROD), and benzyloxyresorufin O-dealkylation (BROD), and 2- and 4-hydroxylation activities of 17β-estradiol (E2) were measured by using yeast-expressed Baikal seal (Pusa sibirica) CYP1A1, 1A2, and 1B1 proteins. Heterologous protein expression of the Baikal seal CYP1s (bsCYP1s) in yeast microsomes was confirmed by reduced CO-difference spectra and immunoblotting. Heterologously expressed human CYP1 enzyme (hCYP1) activities were simultaneously measured and compared with those of bsCYP1 isozymes. Recombinant bsCYP1A1 protein showed the highest Vmax of EROD, followed by MROD, PROD, and BROD, similar to that of hCYP1A1. Vmax/Km ratios of all AROD activities catalyzed by bsCYP1A1 were lower than those catalyzed by hCYP1A1, suggesting less potential for AROD by bsCYP1A1. Enzymatic assays for bsCYP1A2 showed no or minimal AROD activities, while hCYP1A2 displayed MROD and EROD activities. bsCYP1B1 showed an AROD profile (EROD>BROD>MROD>PROD) similar to that of hCYP1B1; however, Vmax/Km ratios of all AROD activities by bsCYP1B1 were higher. Yeast microsomes containing bsCYP1A1 and 1B1 and hCYP1A1, 1A2, and 1B1 metabolized E2 to 2-OHE2 and 4-OHE2, whereas bsCYP1A2 showed no such activity. Comparison of 4- and 2-hydroxylations of E2 by CYP1As suggests that bsCYP1A1, hCYP1A1, and 1A2 preferentially catalyze 2- rather than 4-hydroxylation. As for CYP1B1, the Vmax/Km ratios suggest that both Baikal seal and human CYPs catalyze 4- rather than 2-hydroxylation. Interspecies comparison showed that bsCYP1B1 has higher metabolic potencies for both E2 hydroxylations than does hCYP1B1, whereas the activity of bsCYP1A1 was lower than that of hCYP1A1. Messenger RNA expression levels of bsCYP1s in the liver of Baikal seals indicated that bsCYP1A1 and 1A2 enzymes contributed to 16

  10. Phenotype of the Cyp1a1/1a2/1b1(−/−) Triple-Knockout Mouse*

    PubMed Central

    Dragin, Nadine; Shi, Zhanquan; Madan, Rajat; Karp, Christopher L.; Sartor, Maureen A.; Chen, Chi; Gonzalez, Frank J.; Nebert, Daniel W.

    2009-01-01

    Crossing the Cyp1a1/1a2(−/−) double-knockout mouse with the Cyp1b1(−/−) single-knockout mouse, we generated the Cyp1a1/1a2/1b1(−/−) triple-knockout mouse. In this triple-knockout mouse, statistically significant phenotypes (with incomplete penetrance) included slower weight gain and greater risk of embryolethality before gestational day 11, hydrocephalus, hermaphroditism, and cystic ovaries. Oral benzo[a]pyrene (BaP) daily for 18 days in the Cyp1a1/1a2(−/−) produced the same degree of marked immunosuppression as seen in the Cyp1a1(−/−) mouse; we believe this reflects the absence of intestinal CYP1A1. Oral BaP-treated Cyp1a1/1a2/1b1(−/−) mice showed the same “rescued” response as that seen in the Cyp1a1/1b1(−/−) mouse; we believe this reflects the absence of CYP1B1 in immune tissues. Urinary metabolite profiles were dramatically different between untreated triple-knockout and wild-type; principal components analysis showed that the shifts in urinary metabolite patterns in oral BaP-treated triple-knockout and wild-type mice were also strikingly different. Liver microarray cDNA differential expression (comparing triple-knockout with wild-type) revealed at least 89 genes up- and 62 genes down-regulated (P-value ≤0.00086). Gene Ontology “classes of genes” most perturbed in the untreated triple-knockout (compared with wild-type) include lipid, steroid, and cholesterol biosynthesis and metabolism; nucleosome and chromatin assembly; carboxylic and organic acid metabolism; metal-ion binding; and ion homeostasis. In the triple-knockout compared with the wild-type mice, response to zymosan-induced peritonitis was strikingly exaggerated, which may well reflect down-regulation of Socs2 expression. If a single common molecular pathway is responsible for all of these phenotypes, we suggest that functional effects of the loss of all three Cyp1 genes could be explained by perturbations in CYP1-mediated eicosanoid production, catabolism and

  11. Ab initio quantum study of the photodynamics and absorption spectrum for the coupled 1(1)A2 and 1(1)B1 states of SO2.

    PubMed

    Lévêque, Camille; Komainda, Adrian; Taïeb, Richard; Köppel, Horst

    2013-01-28

    The nonadiabatic photoinduced dynamics occurring in the coupled 1(1)A(2) and 1(1)B(1) excited states of SO(2) is investigated using ab initio quantum dynamical methods. To this end, large scale calculations of the potential energy surfaces have been carried out at the multireference configuration interaction level. All vibrational degrees of freedom of the molecule are considered in the potential energy surface calculations and the quantum dynamical treatment. To deal with the symmetry-allowed conical intersection which occurs between the potential energy surfaces, we use the diabatic picture in the framework of regularized diabatic states. Wave-packet propagation on the coupled surfaces was performed and allowed to reproduce with good accuracy the complex absorption band observed experimentally in the 29,000-42,000 cm(-1) range. This provides a basis for a subsequent theoretical treatment of the high order harmonic spectra of SO(2).

  12. Design synthesis and evaluation of the inhibitory selectivity of novel trans-resveratrol analogues on human recombinant CYP1A1 CYP1A2 and CYP1B1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of trans-stilbene derivatives containing 4’-thiomethyl substituent were synthesized and evaluated for inhibitory activities on human recombinant cytochrome P450(s): CYP1A1, CYP1A2, and CYP1B1. CYP1A2-related metabolism of stilbene derivatives was estimated by using NADPH oxidation assay. A...

  13. Active Site Mutations as a Suitable Tool Contributing to Explain a Mechanism of Aristolochic Acid I Nitroreduction by Cytochromes P450 1A1, 1A2 and 1B1

    PubMed Central

    Milichovský, Jan; Bárta, František; Schmeiser, Heinz H.; Arlt, Volker M.; Frei, Eva; Stiborová, Marie; Martínek, Václav

    2016-01-01

    Aristolochic acid I (AAI) is a plant drug found in Aristolochia species that causes aristolochic acid nephropathy, Balkan endemic nephropathy and their associated urothelial malignancies. AAI is activated via nitroreduction producing genotoxic N-hydroxyaristolactam, which forms DNA adducts. The major enzymes responsible for the reductive bioactivation of AAI are NAD(P)H:quinone oxidoreductase and cytochromes P450 (CYP) 1A1 and 1A2. Using site-directed mutagenesis we investigated the possible mechanisms of CYP1A1/1A2/1B1-catalyzed AAI nitroreduction. Molecular modelling predicted that the hydroxyl groups of serine122/threonine124 (Ser122/Thr124) amino acids in the CYP1A1/1A2-AAI binary complexes located near to the nitro group of AAI, are mechanistically important as they provide the proton required for the stepwise reduction reaction. In contrast, the closely related CYP1B1 with no hydroxyl group containing residues in its active site is ineffective in catalyzing AAI nitroreduction. In order to construct an experimental model, mutant forms of CYP1A1 and 1A2 were prepared, where Ser122 and Thr124 were replaced by Ala (CYP1A1-S122A) and Val (CYP1A2-T124V), respectively. Similarly, a CYP1B1 mutant was prepared in which Ala133 was replaced by Ser (CYP1B1-A133S). Site-directed mutagenesis was performed using a quickchange approach. Wild and mutated forms of these enzymes were heterologously expressed in Escherichia coli and isolated enzymes characterized using UV-vis spectroscopy to verify correct protein folding. Their catalytic activity was confirmed with CYP1A1, 1A2 and 1B1 marker substrates. Using 32P-postlabelling we determined the efficiency of wild-type and mutant forms of CYP1A1, 1A2, and 1B1 reconstituted with NADPH:CYP oxidoreductase to bioactivate AAI to reactive intermediates forming covalent DNA adducts. The S122A and T124V mutations in CYP1A1 and 1A2, respectively, abolished the efficiency of CYP1A1 and 1A2 enzymes to generate AAI-DNA adducts. In contrast

  14. Evaluation of 309 molecules as inducers of CYP3A4, CYP2B6, CYP1A2, OATP1B1, OCT1, MDR1, MRP2, MRP3 and BCRP in cryopreserved human hepatocytes in sandwich culture.

    PubMed

    Badolo, Lassina; Jensen, Bente; Säll, Carolina; Norinder, Ulf; Kallunki, Pekka; Montanari, Dino

    2015-02-01

    1. Regulation of hepatic metabolism or transport may lead to increase in drug clearance and compromise efficacy or safety. In this study, cryopreserved human hepatocytes were used to assess the effect of 309 compounds on the activity and mRNA expression (using qPCR techniques) of CYP1A2, CYP2B6 and CYP3A4, as well as mRNA expression of six hepatic transport proteins: OATP1B1 (SCLO1B1), OCT1 (SLC22A1), MDR1 (ABCB1), MRP2 (ABCC2), MRP3 (ABCC3) and BCRP (ABCG2). 2. The results showed that 6% of compounds induced CYP1A2 activity (1.5-fold increase); 30% induced CYP2B6 while 23% induced CYP3A4. qPCR data identified 16, 33 or 32% inducers of CYP1A2, CYP2B6 or CYP3A4, respectively. MRP2 was induced by 27 compounds followed by MDR1 (16)>BCRP (9)>OCT1 (8)>OATP1B1 (5)>MRP3 (2). 3. CYP3A4 appeared to be down-regulated (≥2-fold decrease in mRNA expression) by 53 compounds, 10 for CYP2B6, 6 for OCT1, 4 for BCRP, 2 for CYP1A2 and OATP1B1 and 1 for MDR1 and MRP2. 4. Structure-activity relationship analysis showed that CYP2B6 and CYP3A4 inducers are bulky lipophilic molecules with a higher number of heavy atoms and a lower number of hydrogen bond donors. Finally, a strategy for testing CYP inducers in drug discovery is proposed.

  15. Polymorphisms in the cytochrome P450 genes CYP1A2, CYP1B1, CYP3A4, CYP3A5, CYP11A1, CYP17A1, CYP19A1 and colorectal cancer risk

    PubMed Central

    Bethke, Lara; Webb, Emily; Sellick, Gabrielle; Rudd, Matthew; Penegar, Stephen; Withey, Laura; Qureshi, Mobshra; Houlston, Richard

    2007-01-01

    Background Cytochrome P450 (CYP) enzymes have the potential to affect colorectal cancer (CRC) risk by determining the genotoxic impact of exogenous carcinogens and levels of sex hormones. Methods To investigate if common variants of CYP1A2, CYP1B1, CYP3A4, CYP3A5, CYP11A1, CYP17A1 and CYP19A1 influence CRC risk we genotyped 2,575 CRC cases and 2,707 controls for 20 single nucleotide polymorphisms (SNPs) that have not previously been shown to have functional consequence within these genes. Results There was a suggestion of increased risk, albeit insignificant after correction for multiple testing, of CRC for individuals homozygous for CYP1B1 rs162558 and heterozygous for CYP1A2 rs2069522 (odds ratio [OR] = 1.36, 95% confidence interval [CI]: 1.03–1.80 and OR = 1.34, 95% CI: 1.00–1.79 respectively). Conclusion This study provides some support for polymorphic variation in CYP1A2 and CYP1B1 playing a role in CRC susceptibility. PMID:17615053

  16. Structure-function relationships of inhibition of human cytochromes P450 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 flavonoid derivatives.

    PubMed

    Shimada, Tsutomu; Tanaka, Katsuhiro; Takenaka, Shigeo; Murayama, Norie; Martin, Martha V; Foroozesh, Maryam K; Yamazaki, Hiroshi; Guengerich, F Peter; Komori, Masayuki

    2010-12-20

    Structure-function relationships for the inhibition of human cytochrome P450s (P450s) 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 flavonoid derivatives were studied. Thirty-two of the 33 flavonoids tested produced reverse type I binding spectra with P450 1B1, and the potencies of binding were correlated with the abilities to inhibit 7-ethoxyresorufin O-deethylation activity. The presence of a hydroxyl group in flavones, for example, 3-, 5-, and 7-monohydroxy- and 5,7-dihydroxyflavone, decreased the 50% inhibition concentration (IC50) of P450 1B1 from 0.6 μM to 0.09, 0.21, 0.25, and 0.27 μM, respectively, and 3,5,7-trihydroxyflavone (galangin) was the most potent, with an IC50 of 0.003 μM. The introduction of a 4'-methoxy- or 3',4'-dimethoxy group into 5,7-dihydroxyflavone yielded other active inhibitors of P450 1B1 with IC50 values of 0.014 and 0.019 μM, respectively. The above hydroxyl and/or methoxy groups in flavone molecules also increased the inhibition activity with P450 1A1 but not always toward P450 1A2, where 3-, 5-, or 7-hydroxyflavone and 4'-methoxy-5,7-dihydroxyflavone were less inhibitory than flavone itself. P450 2C9 was more inhibited by 7-hydroxy-, 5,7-dihydroxy-, and 3,5,7-trihydroxyflavones than by flavone but was weakly inhibited by 3- and 5-hydroxyflavone. Flavone and several other flavonoids produced type I binding spectra with P450 3A4, but such binding was not always related to the inhibitiory activities toward P450 3A4. These results indicate that there are different mechanisms of inhibition for P450s 1A1, 1A2, 1B1, 2C9, and 3A4 by various flavonoid derivatives and that the number and position of hydroxyl and/or methoxy groups highly influence the inhibitory actions of flavonoids toward these enzymes. Molecular docking studies suggest that there are different mechanisms involved in the interaction of various flavonoids with the active site of P450s, thus causing differences in inhibition of these P450 catalytic activities by flavonoids.

  17. Structure-Function Relationships of Inhibition of Human Cytochromes P450 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 Flavonoid Derivatives

    PubMed Central

    Shimada, Tsutomu; Tanaka, Katsuhiro; Takenaka, Shigeo; Murayama, Norie; Martin, Martha V.; Foroozesh, Maryam K.; Yamazaki, Hiroshi; Guengerich, F. Peter; Komori, Masayuki

    2010-01-01

    Structure-function relationships for inhibition of human cytochrome P450s (P450s) 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 flavonoid derivatives were studied. Thirty-two of the 33 flavonoids tested produced Reverse Type I binding spectra with P450 1B1, and the potencies of binding were correlated with the abilities to inhibit 7-ethoxyresorufin O-deethylation activity. The presence of a hydroxyl group in flavones, e.g. 3-, 5-, and 7-monohydroxy- and 5,7-dihydroxyflavone, decreased the 50% inhibition concentration (IC50) of P450 1B1 from 0.6 µM to 0.09, 0.21, 0.25, and 0.27 µM, respectively, and 3,5,7-trihydroxyflavone (galangin) was the most potent, with an IC50 of 0.003 µM. The introduction of a 4’-methoxy- or 3’,4’-dimethoxy group into 5,7-dihydroxyflavone yielded other active inhibitors of P450 1B1 with IC50 values of 0.014 and 0.019 µM, respectively. The above hydroxyl- and/or methoxy-groups in flavone molecules also increased the inhibition activity with P450 1A1 but not always towards P450 1A2, where 3-, 5-, or 7-hydroxyflavone, and 4’-methoxy-5,7-dihydroxyflavone were less inhibitory than flavone itself. P450 2C9 was more inhibited by 7-hydroxy-,5,7-dihydroxy-, and 3,5,7-trihydroxyflavones than by flavone but was weakly inhibited by 3-and 5-hydroxyflavone. Flavone and several other flavonoids produced Type I binding spectra with P450 3A4, but such binding was not always related to the inhibitiory activities towards P450 3A4. These results indicate that there are different mechanisms of inhibition for P450s 1A1, 1A2, 1B1, 2C9, and 3A4 by various flavonoid derivatives and that the number and position of hydroxyl and/or methoxy groups highly influence the inhibitory actions of flavonoids towards these enzymes. Molecular docking studies suggest that there are different mechanisms involved in the interaction of various flavonoids with the active site of P450s, thus causing differences in inhibition of these P450 catalytic activities by flavonoids. PMID

  18. Water pipe (Shisha, Hookah, Arghile) Smoking and Secondhand Tobacco Smoke Effects on CYP1A2 and CYP2A6 Phenotypes as Measured by Caffeine Urine Test.

    PubMed

    Yılmaz, Şenay Görücü; Llerena, Adrián; De Andrés, Fernando; Karakaş, Ümit; Gündoğar, Hasan; Erciyas, Kamile; Kimyon, Sabit; Mete, Alper; Güngör, Kıvanç; Özdemir, Vural

    2017-03-01

    Public policies to stop or reduce cigarette smoking and exposure to secondhand smoke and associated diseases have yielded successful results over the past decade. Yet, the growing worldwide popularity of another form of tobacco consumption, water pipe smoking, has received relatively less attention. To the best of our knowledge, no study to date has evaluated the effects of water pipe smoking on cytochrome P450 (CYP450) activities and drug interaction potential in humans, whereas only limited information is available on the impact of secondhand smoke on drug metabolism. In a sample of 99 healthy volunteers (28 water pipe smokers, 30 secondhand tobacco smoke exposed persons, and 41 controls), we systematically compared CYP1A2 and CYP2A6 enzyme activities in vivo using caffeine urine test. The median self-reported duration of water pipe smoking was 7.5 h/week and 3 years of exposure in total. The secondhand smoke group had a median of 14 h of self-reported weekly exposure to tobacco smoke indoor where a minimum of five cigarettes were smoked/hour for a total of 3.5 years (median). Analysis of variance did not find a significant difference in CYP1A2 and CYP2A6 activities among the three study groups (p > 0.05). Nor was there a significant association between the extent of water pipe or secondhand smoke exposure and the CYP1A2 and CYP2A6 activities (p > 0.05). Further analysis in a subsample with smoke exposure more than the median values also did not reveal a significant difference from the controls. Although we do not rule out an appreciable possible impact of water pipe smoke and secondhand smoke on in vivo activities of these two drug metabolism pathways, variability in smoke constituents from different tobacco consumption methods (e.g., water pipe) might affect drug metabolism in ways that might differ from that of cigarette smoke. Further studies in larger prospective samples are recommended to evaluate water pipe and secondhand tobacco smoke effects

  19. Induction of CYP1A1, CYP1A2, CYP1B1, increased oxidative stress and inflammation in the lung and liver tissues of rats exposed to incense smoke.

    PubMed

    Hussain, Tajamul; Al-Attas, Omar S; Al-Daghri, Nasser M; Mohammed, Arif A; De Rosas, Edgard; Ibrahim, Shebl; Vinodson, Benjamin; Ansari, Mohammed G; El-Din, Khaled I Alam

    2014-06-01

    Incense smoke is increasingly being recognized as a potential environmental contaminant and is linked to malignant and non-malignant respiratory diseases. The detoxification of environmental contaminants including polycyclic aromatic hydrocarbons (PAHs) involves the induction of cytochrome P-450 family enzymes (CYPs) by PAHs. However, the detoxification of PAHs also results in the generation of reactive and unstable intermediary metabolites which are implicated in the oxidative stress, DNA damage, and inflammation. It is unclear whether CYPs are similarly induced by incense smoke, which incidentally contains substantial amounts of PAHs. Here, we examined the impact of long-term incense smoke exposure on the induction of CYPs in male Wister Albino rats. Incense smoke exposure significantly induced the expression of CYP1A1, CYP1A2, and CYP1B1 mRNAs in both lung and liver tissues. The extent of CYP1A1 and CYP1B1 induction was significantly higher in the liver compared to that in the lung, while that of CYP1A2 was greater in the lung than in liver. Incense smoke exposure also increased malondialdehyde and reduced glutathione levels in lung and liver tissues, and the catalase activity in the liver tissues to significant levels. Furthermore incense smoke exposure led to a marked increase in TNF-α and IL-4 levels. The data demonstrate for the first time the capacity of incense smoke to induce CYP1 family enzymes in the target and non-target tissues. Induction of CYPs increased oxidative stress and inflammation appear to be intimately linked to promote the carcinogenesis and health complications in people chronically exposed to incense smoke.

  20. The influence of genetic polymorphisms in Ahr, CYP1A1, CYP1A2, CYP1B1, GST M1, GST T1 and UGT1A1 on urine 1-hydroxypyrene glucuronide concentrations in healthy subjects from Rio Grande do Sul, Brazil.

    PubMed

    Abnet, Christian C; Fagundes, Renato B; Strickland, Paul T; Kamangar, Farin; Roth, Mark J; Taylor, Philip R; Dawsey, Sanford M

    2007-01-01

    Polymorphisms in genes encoding polycyclic aromatic hydrocarbon (PAH) metabolizing enzymes may alter metabolism of these carcinogens and contribute to inter-individual difference in urine concentrations. We investigated the influence of genetic polymorphism on PAH metabolism in urine from 199 healthy subjects from Southern Brazil. We measured urine 1-hydroxypyrene glucuronide (1-OHPG) concentrations using immunoaffinity chromatography and synchronous fluorescence spectroscopy and genotyped subjects using standard methods. Genetic variants in CYP1B1 (rs1056827, rs1800440, rs10012) were strongly associated with urine 1-OHPG with P-values < 0.010. Variants in aryl hydrocarbon receptor (Ahr) (rs4986826), CYP1A1 (rs1799814) and CYP1A2 (rs2069514) were also, although less strongly, associated with changes in urine 1-OHPG concentrations. These variants had P-values of 0.074, 0.040 and 0.025, respectively. The median urine 1-OHPG concentrations (pmol/ml) in the homozygous wild-type and homozygous variants for CYP1B1 (rs10012) and the Ahr, CYP1A1 and CYP1A2 variants listed above were 2.16 and 0.10, 2.16 and 0.41, 2.03 and 0.46, 2.19 and 2.79, respectively. We found no effect of deletions in GST M1 or GST T1, or different alleles of UGT1A1*28. Adjusting for age, sex, place of residence, tobacco smoke exposure, maté drinking, cachaça and barbeque preparation had only a minor impact on the associations. A model containing just exposure variables had an r2 of 0.21; a model with single genotypes for Ahr, CYP1A1, CYP1A2 and CYP1B1 had an r2 of 0.10; and a model combining both exposure and genotype information had a total r2 of 0.33. Our results suggest that CYP1B1 genotypes are strongly associated with urine 1-OHPG concentrations in this population.

  1. 18 CFR 1b.1 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Definitions. 1b.1 Section 1b.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.1 Definitions. For purposes of this part—...

  2. 18 CFR 1b.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Definitions. 1b.1 Section 1b.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.1 Definitions. For purposes of this part—...

  3. 18 CFR 1b.1 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Definitions. 1b.1 Section 1b.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.1 Definitions. For purposes of this part—...

  4. 18 CFR 1b.1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Definitions. 1b.1 Section 1b.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.1 Definitions. For purposes of this part—...

  5. 18 CFR 1b.1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Definitions. 1b.1 Section 1b.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.1 Definitions. For purposes of this part—...

  6. Cytochrome P450 CYP1B1 Interacts with 8-Methoxypsoralen (8-MOP) and Influences Psoralen-Ultraviolet A (PUVA) Sensitivity

    PubMed Central

    Deeni, Yusuf Y.; Ibbotson, Sally H.; Woods, Julie A.; Wolf, C. Roland; Smith, Gillian

    2013-01-01

    Background There are unpredictable inter-individual differences in sensitivity to psoralen-UVA (PUVA) photochemotherapy, used to treat skin diseases including psoriasis. Psoralens are metabolised by cytochrome P450 enzymes (P450), and we hypothesised that variability in cutaneous P450 expression may influence PUVA sensitivity. We previously showed that P450 CYP1B1 was abundantly expressed in human skin and regulated by PUVA, and described marked inter-individual differences in cutaneous CYP1B1 expression. Objectives We investigated whether CYP1B1 made a significant contribution to 8-methoxypsoralen (8-MOP) metabolism, and whether individuality in CYP1B1 activity influenced PUVA sensitivity. Methods We used E. coli membranes co-expressing various P450s and cytochrome P450 reductase (CPR) to study 8-MOP metabolism and cytotoxicity assays in CYP1B1-expressing mammalian cells to assess PUVA sensitivity. Results We showed that P450s CYP1A1, CYP1A2, CYP1B1, CYP2A6 and CYP2E1 influence 8-MOP metabolism. As CYP1B1 is the most abundant P450 in human skin, we further demonstrated that: (i) CYP1B1 interacts with 8-MOP (ii) metabolism of the CYP1B1 substrates 7-ethoxyresorufin and 17-β-estradiol showed concentration-dependent inhibition by 8-MOP and (iii) inhibition of 7-ethoxyresorufin metabolism by 8-MOP was influenced by CYP1B1 genotype. The influence of CYP1B1 on PUVA cytotoxicity was further investigated in a Chinese hamster ovary cell line, stably expressing CYP1B1 and CPR, which was more sensitive to PUVA than control cells, suggesting that CYP1B1 metabolises 8-MOP to a more phototoxic metabolite(s). Conclusion Our data therefore suggest that CYP1B1 significantly contributes to cutaneous 8-MOP metabolism, and that individuality in CYP1B1 expression may influence PUVA sensitivity. PMID:24086543

  7. Development of an In Vitro Model to Screen CYP1B1-Targeted Anticancer Prodrugs.

    PubMed

    Wang, Zhiying; Chen, Yao; Drbohlav, Laura M; Wu, Judy Qiju; Wang, Michael Zhuo

    2016-12-01

    Cytochrome P450 1B1 (CYP1B1) is an anticancer therapeutic target due to its overexpression in a number of steroid hormone-related cancers. One anticancer drug discovery strategy is to develop prodrugs specifically activated by CYP1B1 in malignant tissues to cytotoxic metabolites. Here, we aimed to develop an in vitro screening model for CYP1B1-targeted anticancer prodrugs using the KLE human endometrial carcinoma cell line. KLE cells demonstrated superior stability of CYP1B1 expression relative to transiently transfected cells and did not express any appreciable amount of cognate CYP1A1 or CYP1A2, which would have compromised the specificity of the screening assay. The effect of two CYP1B1-targeted probe prodrugs on KLE cells was evaluated in the absence and presence of a CYP1B1 inhibitor to chemically "knock out" CYP1B1 activity (CYP1B1 inhibited). Both probe prodrugs were more toxic to KLE cells than to CYP1B1-inhibited KLE cells and significantly induced G0/G1 arrest and decreased the S phase in KLE cells. They also exhibited pro-apoptotic effects in KLE cells, which were attenuated in CYP1B1-inhibited KLE cells. In summary, a KLE cell-based model has been characterized to be suitable for identifying CYP1B1-targeted anticancer prodrugs and should be further developed and employed for screening chemical libraries.

  8. 7 CFR 1b.1 - Purpose.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.1 Purpose. (a) This part supplements the regulations for implementation of the National Environmental Policy Act (NEPA), for which regulations were published by the Council on Environmental Quality (CEQ) in 40 CFR parts 1500 through 1508. This...

  9. Tumor-specific expression of cytochrome P450 CYP1B1.

    PubMed

    Murray, G I; Taylor, M C; McFadyen, M C; McKay, J A; Greenlee, W F; Burke, M D; Melvin, W T

    1997-07-15

    Cytochrome P450 CYP1B1 is a recently cloned dioxin-inducible form of the cytochrome P450 family of xenobiotic metabolizing enzymes. An antibody raised against a peptide specific for CYP1B1 was found to recognize CYP1B1 expressed in human lymphoblastoid cells but not to recognize other forms of cytochrome P450, particularly CYP1A1 and CYP1A2. Using this antibody, the cellular distribution and localization of CYP1B1 were investigated by immunohistochemistry in a range of malignant tumors and corresponding normal tissues. CYP1B1 was found to be expressed at a high frequency in a wide range of human cancers of different histogenetic types, including cancers of the breast, colon, lung, esophagus, skin, lymph node, brain, and testis. There was no detectable immunostaining for CYP1B1 in normal tissues. These results provide the basis for the development of novel methods of cancer diagnosis based on the identification of CYP1B1 in tumor cells and the development of anticancer drugs that are selectively activated in tumors by CYP1B1.

  10. Quinazoline derivatives as selective CYP1B1 inhibitors.

    PubMed

    Mohd Siddique, Mohd Usman; McCann, Glen J P; Sonawane, Vinay R; Horley, Neill; Gatchie, Linda; Joshi, Prashant; Bharate, Sandip B; Jayaprakash, Venkatesan; Sinha, Barij N; Chaudhuri, Bhabatosh

    2017-04-21

    CYP1B1 is implicated to have a role in the development of breast, ovarian, renal, skin and lung carcinomas. It has been suggested that identification of potent and specific CYP1B1 inhibitors can lead to a novel treatment of cancer. Flavonoids have a compact rigid skeleton which fit precisely within the binding cavity of CYP1B1. Systematic isosteric replacement of flavonoid 'O' atom with 'N' atom led to the prediction that a 'quinazoline' scaffold could be the basis for designing potential CYP1B1 inhibitors. A total of 20 quinazoline analogs were synthesized and screened for CYP1B1 and CYP1A1 inhibition in Sacchrosomes™. IC50 determinations of six compounds with capability of inhibiting CYP1B1 identified quinazolines 5c and 5h as the best candidates for CYP1B1 inhibition, with IC50 values in the nM range. Further selectivity studies with homologous CYPs, belonging to the CYP1, CYP2 and CYP3 family of enzymes, showed that the compounds are likely to be free from critical drug-drug interaction liability. Molecular modelling studies were performed to rationalize the observed enzymatic inhibitions. Further biological studies in live yeast and human cells, harboring CYP1A1 and CYP1B1 enzymes, have illustrated the most potent compounds' cellular permeability and capability of potently inhibiting CYP1B1 enzyme expressed within live cells.

  11. CYP1B1 and hormone-induced cancer.

    PubMed

    Gajjar, Ketan; Martin-Hirsch, Pierre L; Martin, Francis L

    2012-11-01

    Cancers in hormone-responsive tissues (e.g., breast, ovary, endometrium, prostate) occur at high incidence rates worldwide. However, their genetic basis remains poorly understood. Studies to date suggest that endogenous/exogenous oestrogen and environmental carcinogens may play a role in development and/or progression of hormone-induced cancers via oxidative oestrogen metabolism. Cytochrome P450 1B1 is a key enzyme in its oestrogen metabolism pathway, giving rise to hydroxylation and conjugation. Although CYP1B1 is expressed in many cancers, particularly high levels of expression are observed in oestrogen-mediated disease. CYP1B1 is more readily found in tumour tissue compared to normal. Given the role of CYP1B1 in pro-carcinogen and oestrogen metabolism, polymorphisms in CYP1B1 could result in modifications in its enzyme activity and subsequently lead to hormone-mediated carcinogenesis. CYP1B1 may also be involved in progression of the disease by altering the tissue response to hormones and clinical response to chemotherapy. The exact mechanism behind these events is complex and unclear. Only a few functional single nucleotide polymorphisms of CYP1B1 are known to result in amino acid substitutions and have been extensively investigated. Studies examining the contribution of different CYP1B1 alleles to hormone-mediated cancer risks are inconsistent. The main focus of this review is to appraise the available studies linking the pathogenesis of the hormone-induced cancers to various CYP1B1 polymorphisms. Additionally, we explore the role of a neuronal protein, γ-synuclein, in CYP1B1-mediated pathogenesis.

  12. CYP1B1: a unique gene with unique characteristics.

    PubMed

    Faiq, Muneeb A; Dada, Rima; Sharma, Reetika; Saluja, Daman; Dada, Tanuj

    2014-01-01

    CYP1B1, a recently described dioxin inducible oxidoreductase, is a member of the cytochrome P450 superfamily involved in the metabolism of estradiol, retinol, benzo[a]pyrene, tamoxifen, melatonin, sterols etc. It plays important roles in numerous physiological processes and is expressed at mRNA level in many tissues and anatomical compartments. CYP1B1 has been implicated in scores of disorders. Analyses of the recent studies suggest that CYP1B1 can serve as a universal/ideal cancer marker and a candidate gene for predictive diagnosis. There is plethora of literature available about certain aspects of CYP1B1 that have not been interpreted, discussed and philosophized upon. The present analysis examines CYP1B1 as a peculiar gene with certain distinctive characteristics like the uniqueness in its chromosomal location, gene structure and organization, involvement in developmentally important disorders, tissue specific, not only expression, but splicing, potential as a universal cancer marker due to its involvement in key aspects of cellular metabolism, use in diagnosis and predictive diagnosis of various diseases and the importance and function of CYP1B1 mRNA in addition to the regular translation. Also CYP1B1 is very difficult to express in heterologous expression systems, thereby, halting its functional studies. Here we review and analyze these exceptional and startling characteristics of CYP1B1 with inputs from our own experiences in order to get a better insight into its molecular biology in health and disease. This may help to further understand the etiopathomechanistic aspects of CYP1B1 mediated diseases paving way for better research strategies and improved clinical management.

  13. CYP1B1-mediated Pathobiology of Primary Congenital Glaucoma.

    PubMed

    Faiq, Muneeb A; Dada, Rima; Qadri, Rizwana; Dada, Tanuj

    2015-01-01

    CYP1B1 is a dioxin-inducible enzyme belonging to the cytochrome P450 superfamily. It has been observed to be important in a variety of developmental processes including in utero development of ocular structures. Owing to its role in the developmental biology of eye, its dysfunction can lead to ocular developmental defects. This has been found to be true and CYP1B1 mutations have been observed in a majority of primary congenital glaucoma (PCG) patients from all over the globe. Primary congenital glaucoma is an irreversibly blinding childhood disorder (onset at birth or early infancy) typified by anomalous development of trabecular meshwork (TM). How CYP1B1 causes PCG is not known; however, some basic investigations have been reported. Understanding the CYP1B1 mediated etiopathomechanism of PCG is very important to identify targets for therapy and preventive management. In this perspective, we will make an effort to reconstruct the pathomechanism of PCG in the light of already reported information about the disease and the CYP1B1 gene. How to cite this article: Faiq MA, Dada R, Qadri R, Dada T. CYP1 B1-mediated Pathobiology of Primary Congenital Glaucoma. J Curr Glaucoma Pract 2015;9(3):77-80.

  14. CYP1B1-mediated Pathobiology of Primary Congenital Glaucoma

    PubMed Central

    Faiq, Muneeb A; Dada, Rima; Qadri, Rizwana

    2015-01-01

    ABSTRACT CYP1B1 is a dioxin-inducible enzyme belonging to the cytochrome P450 superfamily. It has been observed to be important in a variety of developmental processes including in utero development of ocular structures. Owing to its role in the developmental biology of eye, its dysfunction can lead to ocular developmental defects. This has been found to be true and CYP1B1 mutations have been observed in a majority of primary congenital glaucoma (PCG) patients from all over the globe. Primary congenital glaucoma is an irreversibly blinding childhood disorder (onset at birth or early infancy) typified by anomalous development of trabecular meshwork (TM). How CYP1B1 causes PCG is not known; however, some basic investigations have been reported. Understanding the CYP1B1 mediated etiopathomechanism of PCG is very important to identify targets for therapy and preventive management. In this perspective, we will make an effort to reconstruct the pathomechanism of PCG in the light of already reported information about the disease and the CYP1B1 gene. How to cite this article: Faiq MA, Dada R, Qadri R, Dada T. CYP1 B1-mediated Pathobiology of Primary Congenital Glaucoma. J Curr Glaucoma Pract 2015;9(3):77-80. PMID:26997841

  15. Cytochrome P1B1 (CYP1B1) polymorphisms and cancer risk: a meta-analysis of 52 studies.

    PubMed

    Li, Cuiping; Long, Bingshuang; Qin, Xianjing; Li, Weixiong; Zhou, Yang

    2015-01-02

    CYP1B1 plays a critical role in the oxidative metabolism of a variety of exogenous compounds, including carcinogenic compounds, which may be activated during metabolism. There are only a few studies that have examined the association between the two polymorphisms and cancer, and that these studies have been inconclusive. Hence, the aim of the present meta-analysis was to evaluate the relationship between polymorphisms in CYP1B1 G119T and A453G and cancer risk. We performed a detailed search using the PubMed and EMBASE libraries to obtain all relevant published reports on the relationship between the G119T and A453G polymorphisms in CYP1B1 and cancer risk. Combined odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by Stata version 11.2. We conducted stratified analyses based on cancer types, ethnicity, source of controls, and quality assessments. We also made assessments of heterogeneity tests, sensitivity analyses, and publication bias. There were a total of 25 articles with 15,376 cases and 18,382 controls concerning CYP1B1 G119T and 40 articles with 27,983 cases and 35,839 controls concerning A453G polymorphisms. Regarding G119T, the combined results indicate that the variant genotypes were significantly associated with a slightly increased cancer risk in comparison to the homozygote (TT versus GG: p=0.006, OR=1.231, 95% CI: 1.061-1.428), especially for breast cancer and prostate cancer. Moreover, significantly increased associations with cancer risk were demonstrated in Asians in all genetic models. The combined results indicated no association of A453G with cancer risk; however, an association was observed specifically for prostate cancer. This meta-analysis suggests that the CYP1B1 G119T polymorphism may confer to genetic susceptibility to cancer in Asians, especially to breast cancer and prostate cancer. The A453G polymorphism was found to modify the risk of prostate cancer.

  16. Cytochrome P1B1 (CYP1B1) polymorphisms and ovarian cancer risk: a meta-analysis.

    PubMed

    Gajjar, Ketan; Owens, Gemma; Sperrin, Matthew; Martin-Hirsch, Pierre L; Martin, Francis L

    2012-12-16

    CYP1B1 is a key P450 enzyme involved in the metabolism of exogenous and endogenous substrates and plays a key role in hormone-induced carcinogenesis. Risk factors for ovarian cancer are related to hormonal exposure and reproduction, and polymorphisms within genes involved in metabolism of oestrogen and certain xenobiotics may influence the risk of developing ovarian cancer. Current meta-analysis evaluated four CYP1B1 polymorphisms (Leu432Val, Arg48Gly, Ala119Ser and Asn453Ser) for their association with ovarian cancer risk. A search of the MEDLINE bibliographic database for the period up to April 2012 identified five relevant studies. With regards to Leu432Val polymorphism, all of the five studies were eligible (1199 cases and 2596 controls) for analysis, while for Arg48Gly (799 cases and 1169 controls), Ala119Ser (799 cases and 1172 controls) and Asn453Ser (361cases and 1577 controls) only two studies were eligible for analysis. Fixed-effect models were used to estimate pooled odds ratios (OR) with 95% confidence intervals (95% CI) and chi-square based Q-test was used to test for heterogeneity. The pooled OR (95% CI) for CYP1B1_Leu432Val polymorphism were 1.1 (0.84-1.31) for heterozygous subjects and 0.82 (0.57-1.17) for homozygous Val subjects. In a recessive model, homozygous carriers of Leu432Val showed a weak trend towards reduced risk as compared to 'wild type' and heterozygous carriers (OR 0.8, 95% CI; 0.66-0.99); however, this association was of limited significance. Regarding Arg48Gly, the pooled OR (95% CI) were 1.06 (0.89-1.27) for heterozygous and 0.98 (1.72-1.33) for homozygous Gly subjects. With respect to Ala119Ser and Asn453Ser, the pooled OR were 1.06 (0.87-1.29) and 1.24 (0.94-1.63) for heterozygous and 1.1 (0.8-1.52) and 1.09 (0.5-2.34) for homozygous respectively. In conclusion, this meta-analysis suggests that CYP1B1 polymorphisms are not associated with ovarian cancer risk. Studies evaluating CYP1B1_Leu432Val polymorphism are required to

  17. Proteasomal degradation of human CYP1B1: effect of the Asn453Ser polymorphism on the post-translational regulation of CYP1B1 expression.

    PubMed

    Bandiera, Silvio; Weidlich, Simone; Harth, Volker; Broede, Peter; Ko, Yun; Friedberg, Thomas

    2005-02-01

    Allelic variations in CYP1B1 are reported to modulate the incidence of several types of cancer. To provide a mechanistic basis for this association, we investigated the impact of nonsilent allelic changes on the intracellular levels and post-translational regulation of CYP1B1 protein. When transiently expressed in COS-1 cells, either in the presence or absence of recombinant cytochrome P450 reductase, the cellular level of the CYP1B1.4 allelic variant (containing a Ser at the amino acid position 453; Ser453) was 2-fold lower compared with the other four allelic CYP1B1 proteins (containing Asn453), as analyzed by both immunoblotting and ethoxyresorufin O-deethylase activity. This difference was caused by post-translational regulation; as in the presence of cycloheximide, the rate of degradation of immunodetectable and enzymatically active CYP1B1.4 was distinctly faster than that of CYP1B1.1. Pulse-chase analysis revealed that the half-life of CYP1B1.4 was a mere 1.6 h compared with 4.8 h for CYP1B1.1. The presence of the proteasome inhibitor MG132 [N-benzoyloxycarbonyl (Z)-Leu-Leuleucinal] increased the stability not only of immunodetectable CYP1B1, but also--unexpectedly given the size of the proteasome access channel--increased the stability of enzymatically active CYP1B1. The data presented herein also demonstrate that CYP1B1 is targeted for its polymorphism-dependent degradation by polyubiquitination but not phosphorylation. Our results importantly provide a mechanism to explain the recently reported lower incidence of endometrial cancer in individuals carrying the CYP1B1*4 compared with the CYP1B1*1 haplo-type. In addition, the mechanistic paradigms revealed herein may explain the strong overexpression of CYP1B1 in tumors compared with nondiseased tissues.

  18. Cyp1b1 Mediates Periostin Regulation of Trabecular Meshwork Development by Suppression of Oxidative Stress

    PubMed Central

    Zhao, Yun; Wang, Shoujian; Sorenson, Christine M.; Teixeira, Leandro; Dubielzig, Richard R.; Peters, Donna M.; Conway, Simon J.; Jefcoate, Colin R.

    2013-01-01

    Mutation in CYP1B1 has been reported for patients with congenital glaucoma. However, the underlying mechanisms remain unknown. Here we show increased diurnal intraocular pressure (IOP) in Cyp1b1-deficient (Cyp1b1−/−) mice. Cyp1b1−/− mice presented ultrastructural irregular collagen distribution in their trabecular meshwork (TM) tissue along with increased oxidative stress and decreased levels of periostin (Postn). Increased levels of oxidative stress and decreased levels of Postn were also detected in human glaucomatous TM tissues. Furthermore, Postn-deficient mice exhibited TM tissue ultrastructural abnormalities similar to those of Cyp1b1−/− mice. Administration of the antioxidant N-acetylcysteine (NAC) restored structural abnormality of TM tissue in Cyp1b1−/− mice. In addition, TM cells prepared from Cyp1b1−/− mice exhibited increased oxidative stress, altered adhesion, and decreased levels of Postn. These aberrant cellular responses were reversed in the presence of NAC or by restoration of Cyp1b1 expression. Cyp1b1 knockdown or inhibition of CYP1B1 activity in Cyp1b1+/+ TM cells resulted in a Cyp1b1−/− phenotype. Thus, metabolic activity of CYP1B1 contributes to oxidative homeostasis and ultrastructural organization and function of TM tissue through modulation of Postn expression. PMID:23979599

  19. Cyp1b1 exerts opposing effects on intestinal tumorigenesis via exogenous and endogenous substrates

    PubMed Central

    Halberg, Richard B.; Larsen, Michele Campaigne; Elmergreen, Tammy L.; Ko, Alex Y.; Irving, Amy A.; Clipson, Linda; Jefcoate, Colin R.

    2008-01-01

    Cytochrome P450 1B1 (Cyp1b1) metabolism contributes to physiological functions during embryogenesis, but also to carcinogenic activation of polycyclic aromatic hydrocarbons (PAH). We generated Cyp1b1-deficient mice carrying the Min allele of the Adenomatous polyposis coli gene. These Cyp1b1-deficient Min mice developed twice as many tumors as Min controls, which, however, remained similar in size and histology. Tumors from older (130 day) Cyp1b1-deficient Min mice exhibited focal areas of nuclear atypia associated with less organized epithelia. The metabolism of endogenous substrates by Cyp1b1, therefore, suppresses tumor initiation, but also affects progression. Treatment of Min mice with 7,12-dimethylbenzanthracene (DMBA) doubled both tumor multiplicity and size within 20 days, but not when mice lacked Cyp1b1. This was paralleled by an abnormal staining of crypts with β catenin, phospho-IKK, and ReIA, which may represent an early stage of tumorigenesis similar to aberrant crypt formation. Cyp1b1 deletion did not affect circulating DMBA and metabolites. Cyp1b1 expression was higher in the tumors compared to normal small intestines. Increased tumorigenesis may, therefore, arise from generation of DMBA metabolites by Cyp1b1 in the developing tumors. Benzo(a)pyrene (BP), which is similarly activated by Cyp1b1 in vitro, did not affect tumorigenesis in Min mice. By contrast, BP and DMBA each suppressed tumor multiplicity in absence of Cyp1b1. Cyp1b1 metabolism of DMBA and endogenous oxygenation products may each impact a tumor promoting NF-κB. activation, whereas Ah receptor activation by PAH effects suppression. Tumorigenesis may, therefore, depend on activation of PAH by Cyp1b1, and on off-setting suppression by Cyp1b1 of endogenous tumor-enhancing substrates. PMID:18794127

  20. CYP1B1 expression, a potential risk factor for breast cancer

    SciTech Connect

    Goth-Goldstein, Regine; Erdmann, Christine A.; Russell, Marion

    2001-05-31

    CYP1B1 expression in non-tumor breast tissue from breast cancer patients and cancer-free individuals was determined to test the hypothesis that high CYP1B1 expression is a risk factor for breast cancer. Large interindividual variations in CYP1B1 expression were found with CYP1B1 levels notably higher in breast cancer patients than cancer-free individuals. The results indicate that CYP1B1 might play a role in breast cancer either through increased PAH activation or through metabolism of endogenous estrogen to a carcinogenic derivative.

  1. Role of CYP1B1 in PAH-DNA Adduct Formation and Breast Cancer Risk

    DTIC Science & Technology

    2006-03-01

    xenobiotic metabolism, CYP1B1 , gene expression, genetic polymorphism , DNA adducts 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...Task 2: Characterize the breast tissue samples in respect to CYP1B1 expression and CYP1B1 polymorphism – in progress a. Isolate DNA and RNA from...19.78) 0.06 – 73.7 d. Perform CYP1B1 genotype analysis The CYP1B1 genotype at two polymorphic sites located in the catalytic side of the enzyme

  2. CYP1B1 mRNA inducibility due to benzo(a)pyrene is modified by the CYP1B1 L432V gene polymorphism.

    PubMed

    Helmig, Simone; Wenzel, Sibylle; Maxeiner, Hagen; Schneider, Joachim

    2014-07-01

    Benzo(a)pyrene (BaP), a primary component of tobacco smoke, is activated by cytochrome P450 1B1 (CYP1B1). Smokers homozygous for the C-allele (*1/*1) at the CYP1B1 Leu432Val polymorphism have shown increased CYP1B1 expression, compared to smokers homozygous for the G-allele *3/*3. Since no difference has been shown in CYP1B1 expression between both genotypes in non-smokers, we assumed that the genetic impact is produced in combination with an exogenous induction (e.g. BaP). To confirm this theory and to quantify the effect, we induced human leucocytes with increasing BaP concentrations and determined CYP1B1 mRNA expression with real-time polymerase chain reaction (PCR). We incubated human leucocytes from 27 healthy donors with BaP concentrations ranging from 2.5 to 250 µM. We identified the CYP1B1 genotypes by melting curve analysis and assessed relative CYP1B1 mRNA expression using real-time PCR. Expression was related to β-2-microglobulin with the 2(-ΔΔCT) method. Inducibility of CYP1B1 mRNA by BaP was higher in leucocytes carrying the CYP1B1*1/*1 genotype than in leucocytes carrying the CYP1B1*3/*3 genotype (P = 0.012). We revealed significant differences, with BaP concentrations of 2.5 µM (P = 0.0094), 5 µM (P = 0.027), 10 µM (P = 0.0006), 25 µM (P = 0.0007) and 50 µM (P = 0.017). Homozygous carriers of the C-allele (*1/*1) at the CYP1B1 Leu432Val polymorphism show a higher response to environmental factors, such as carcinogenic BaP, than homozygous carriers of the G-allele *3/*3.

  3. CYP1B1 is polymorphic in cynomolgus and rhesus macaques.

    PubMed

    Uno, Yasuhiro; Matsushita, Akinori; Yamazaki, Hiroshi

    2011-09-01

    Cytochrome P450 (CYP) 1B1 is involved in the metabolic activation of various procarcinogens, and some CYP1B1 genetic variants alter CYP1B1-dependent procarcinogen metabolism. Cynomolgus and rhesus macaques are frequently used in toxicity tests due to their evolutionary closeness to humans. In this study, we attempted to identify CYP1B1 genetic variants in 13 cynomolgus and 4 rhesus macaques. A total of 17 genetic variants were identified, including 8 non-synonymous genetic variants, indicating that, similar to humans, CYP1B1 is polymorphic in macaques. These CYP1B1 genetic variants could be the basis for understanding potential inter-animal differences in macaque CYP1B1-dependent metabolism of promutagens.

  4. Cyp1B1 mRNA expression in correlation to cotinine levels with respect to the Cyp1B1 L432V gene polymorphism.

    PubMed

    Helmig, Simone; Seelinger, Jens Udo; Philipp-Gehlhaar, Monika; Döhrel, Juliane; Schneider, Joachim

    2010-12-01

    Cytochrome P450 1B1 (CYP1B1) is involved in the activation of a broad spectrum of procarcinogens. An association of the Cyp1B1 Leu432Val polymorphism with cancer as well as an impact on the enzyme activity has been described. To study gene-environmental interactions we investigated the quantitative Cyp1B1 mRNA expression in smokers (N = 102) and non-smokers (N = 192) with regards to the Cyp1B1 L432V gene polymorphism. Tobacco smoke exposure was assessed by serum cotinine levels. Genotypes were analysed by melting curve analysis and quantification of Cyp1B1 mRNA by real-time PCR. In comparing Cyp1B1 expression, significant differences between the two homozygote genotypes *1/*1 and *3/*3 (0.105 ± 0.019; n = 26 vs. 0.051 ± 0.017; n = 14; P = 0.039) and between the heterozygote genotype *1/*3 and *3/*3 (0.121 ± 0.029; n = 55 vs. 0.051 ± 0.017; n = 14; P = 0.039) of smokers were revealed. According to the serum cotinine levels, three subgroups (low; medium; high) were build. The group "high" (0.248 ± 0.089; n = 32) showed proportionally high Cyp1B1 mRNA expression compared to "medium" (0.101 ± 0.024; n = 33), "low" (0.086 ± 0.015; n = 32) and non-smokers (0.084 ± 0.007; n = 176). This result was reflected in the homozygote *1/*1 and the heterozygote *1/*3 genotypes. In contrast the homozygote *3/*3 genotype was missing the high Cyp1B1 mRNA expression in the cotinine subgroup "high". Our results suggest that genotypes carrying the C-allele (*1/*1 and *1/*3) at Cyp1B1 Leu432Val polymorphism show a higher response to environmental factors, such as tobacco smoke than homozygote *3/*3 genotypes.

  5. Effect of Ginkgo biloba extract on procarcinogen-bioactivating human CYP1 enzymes: Identification of isorhamnetin, kaempferol, and quercetin as potent inhibitors of CYP1B1

    SciTech Connect

    Chang, Thomas K.H. . E-mail: tchang@interchange.ubc.ca; Chen Jie; Yeung, Eugene Y.H.

    2006-05-15

    In the present study, we investigated the effect of Ginkgo biloba extracts and some of its individual constituents on the catalytic activity of human cytochrome P450 enzymes CYP1B1, CYP1A1, and CYP1A2. G. biloba extract of known abundance of terpene trilactones and flavonol glycosides inhibited 7-ethoxyresorufin O-dealkylation catalyzed by human recombinant CYP1B1, CYP1A1, and CYP1A2, and human liver microsomes, with apparent K {sub i} values of 2 {+-} 0.3, 5 {+-} 0.5, 16 {+-} 1.4, and 39 {+-} 1.2 {mu}g/ml (mean {+-} SE), respectively. In each case, the mode of inhibition was of the mixed type. Bilobalide, ginkgolides A, B, C, and J, quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside, and isorhamentin 3-O-rutinoside were not responsible for the inhibition of CYP1 enzymes by G. biloba extract, as determined by experiments with these individual chemicals at the levels present in the extract. In contrast, the aglycones of quercetin, kaempferol, and isorhamentin inhibited CYP1B1, CYP1A1, and CYP1A2. Among the three flavonol aglycones, isorhamentin was the most potent in inhibiting CYP1B1 (apparent K {sub i} = 3 {+-} 0.1 nM), whereas quercetin was the least potent in inhibiting CYP1A2 (apparent K {sub i} 418 {+-} 50 nM). The mode of inhibition was competitive, noncompetitive, or mixed, depending on the enzyme and the flavonol. G. biloba extract also reduced benzo[a]pyrene hydroxylation, and the effect was greater with CYP1B1 than with CYP1A1 as the catalyst. Overall, our novel findings indicate that G. biloba extract and the flavonol aglycones isorhamnetin, kaempferol, and quercetin preferentially inhibit the in vitro catalytic activity of human CYP1B1.

  6. CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer

    DTIC Science & Technology

    2008-06-01

    AD_________________ Award Number: W81XWH-04-1-0579 TITLE: CYP1B1 Polymorphism as a Risk Factor...TITLE AND SUBTITLE CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-04-1-0579...collected; as well as further experimentation with aim #1to be performed. 15. SUBJECT TERMS CYP1B1 , Polymorphism , Prostate cancer, Race-related

  7. Role of CYP1B1 in PAH-DNA Adduct Formation and Breast Cancer Risk

    DTIC Science & Technology

    2004-09-01

    The cytochrome P450 enzyme CYP1B1 is a major enzyme involved in metabolizing polycyclic aromatic hydrocarbons (PAHs) to reactive intermediates. Given...that certain exposure to PAHs may be a breast cancer risk factor, we have set out to examine CYP1B1 gene expression in breast tissue. After...hired Research Coordinators and interviewers have been trained and recruitment of participants has begun. The method to measure CYP1B1 expression has

  8. CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer

    DTIC Science & Technology

    2006-06-01

    AD_________________ Award Number: W81XWH-04-1-0579 TITLE: CYP1B1 Polymorphism as a Risk Factor...TITLE AND SUBTITLE CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-04-1-0579...hypothesis, single nucleotide polymorphisms (SNPs) at three codons (119, 432, and 453) of CYP1B1 have been evaluated to determine if they are risk factors

  9. Cyp1b1 Regulates Ocular Fissure Closure Through a Retinoic Acid–Independent Pathway

    PubMed Central

    Williams, Antionette L.; Eason, Jessica; Chawla, Bahaar; Bohnsack, Brenda L.

    2017-01-01

    Purpose Mutations in the CYP1B1 gene are the most commonly identified genetic causes of primary infantile-onset glaucoma. Despite this disease association, the role of CYP1B1 in eye development and its in vivo substrate remain unknown. In the present study, we used zebrafish to elucidate the mechanism by which cyp1b1 regulates eye development. Methods Zebrafish eye and neural crest development were analyzed using live imaging of transgenic zebrafish embryos, in situ hybridization, immunostaining, TUNEL assay, and methylacrylate sections. Cyp1b1 and retinoic acid (RA) levels were genetically (morpholino oligonucleotide antisense and mRNA) and pharmacologically manipulated to examine gene function. Results Using zebrafish, we observed that cyp1b1 was expressed in a specific spatiotemporal pattern in the ocular fissures of the developing zebrafish retina and regulated fissure patency. Decreased Cyp1b1 resulted in the premature breakdown of laminin in the ventral fissure and altered subsequent neural crest migration into the anterior segment. In contrast, cyp1b1 overexpression inhibited cell survival in the ventral ocular fissure and prevented fissure closure via an RA-independent pathway. Cyp1b1 overexpression also inhibited the ocular expression of vsx2, pax6a, and pax6b and increased the extraocular expression of shha. Importantly, embryos injected with human wild-type but not mutant CYP1B1 mRNA also showed colobomas, demonstrating the evolutionary and functional conservation of gene function between species. Conclusions Cyp1b1 regulation of ocular fissure closure indirectly affects neural crest migration and development through an RA-independent pathway. These studies provide insight into the role of Cyp1b1 in eye development and further elucidate the pathogenesis of primary infantile-onset glaucoma. PMID:28192799

  10. Cytochrome 450 1B1 (CYP1B1) polymorphisms associated with response to docetaxel in Castration-Resistant Prostate Cancer (CRPC) patients

    PubMed Central

    2010-01-01

    Background The selection of patients according to key genetic characteristics may help to tailor chemotherapy and optimize the treatment in Castration-Resistant Prostate Cancer (CRPC) patients. Functional polymorphisms within the cytochrome P450 1B1 (CYP1B1) gene have been associated with alterations in enzymatic expression and activity and may change sensitivity to the widely used docetaxel regimen. Methods CYP1B1 genotyping was performed on blood samples of 60 CRPC patients treated with docetaxel, using TaqMan probes-based assays. Association between CYP1B1-142C>G (leading to the 48ArgGly transition), 4326C>G (432LeuVal), and 4390A>G (453AsnSer) polymorphisms and treatment response, progression-free-survival (PFS) and overall-survival (OS) was estimated using Pearson χ2 test, Kaplan-Meier curves and Log-rank test. Results Patients carrying the CYP1B1-432ValVal genotype experienced a significantly lower response-rate (P = 0.014), shorter progression-free-survival (P = 0.032) and overall-survival (P < 0.001). Multivariate analyses and correction for multiple comparisons confirmed its prognostic significance for OS. No significant associations were found among other polymorphisms and both response and clinical outcome. Conclusions CYP1B1-4326C>G (432LeuVal) polymorphism emerged as possible predictive marker of response and clinical outcome to docetaxel in CRPC patients and may represent a potential new tool for treatment optimization. Larger prospective trials are warranted to validate these findings, which might be applied to the future practice of CRPC treatment. PMID:20875115

  11. Flavopiridol Pharmacogenetics: Clinical and Functional Evidence for the Role of SLCO1B1/OATP1B1 in Flavopiridol Disposition

    PubMed Central

    Ni, Wenjun; Ji, Jia; Dai, Zunyan; Papp, Audrey; Johnson, Amy J.; Ahn, Sunjoo; Farley, Katherine L.; Lin, Thomas S.; Dalton, James T.; Li, Xiaobai; Jarjoura, David; Byrd, John C.; Sadee, Wolfgang; Grever, Michael R.; Phelps, Mitch A.

    2010-01-01

    Background Flavopiridol is a cyclin-dependent kinase inhibitor in phase II clinical development for treatment of various forms of cancer. When administered with a pharmacokinetically (PK)-directed dosing schedule, flavopiridol exhibited striking activity in patients with refractory chronic lymphocytic leukemia. This study aimed to evaluate pharmacogenetic factors associated with inter-individual variability in pharmacokinetics and outcomes associated with flavopiridol therapy. Methodology/Principal Findings Thirty-five patients who received single-agent flavopiridol via the PK-directed schedule were genotyped for 189 polymorphisms in genes encoding 56 drug metabolizing enzymes and transporters. Genotypes were evaluated in univariate and multivariate analyses as covariates in a population PK model. Transport of flavopiridol and its glucuronide metabolite was evaluated in uptake assays in HEK-293 and MDCK-II cells transiently transfected with SLCO1B1. Polymorphisms in ABCC2, ABCG2, UGT1A1, UGT1A9, and SLCO1B1 were found to significantly correlate with flavopiridol PK in univariate analysis. Transport assay results indicated both flavopiridol and flavopiridol-glucuronide are substrates of the SLCO1B1/OATP1B1 transporter. Covariates incorporated into the final population PK model included bilirubin, SLCO1B1 rs11045819 and ABCC2 rs8187710. Associations were also observed between genotype and response. To validate these findings, a second set of data with 51 patients was evaluated, and overall trends for associations between PK and PGx were found to be consistent. Conclusions/Significance Polymorphisms in transport genes were found to be associated with flavopiridol disposition and outcomes. Observed clinical associations with SLCO1B1 were functionally validated indicating for the first time its relevance as a transporter of flavopiridol and its glucuronide metabolite. A second 51-patient dataset indicated similar trends between genotype in the SLCO1B1 and other

  12. MISR Level 1A CCD, 1B1, 1B2, and Browse Products

    Atmospheric Science Data Center

    2013-04-01

    ... 1B1 Radiance, CCD Science;  Local Mode Data (Hi-Res Target Scenes): Terrain/Ellipsoid-Projected Radiance, 1B1 Radiance ... transform fix. ROI Image Matching improvements to blunder detection algorithm and to Image Coordinate Correction. New ancillary ...

  13. Immunolocalization of CYP1B1 in normal, human, fetal and adult eyes.

    PubMed

    Doshi, Manali; Marcus, Craig; Bejjani, Bassem A; Edward, Deepak P

    2006-01-01

    CYP1B1 is a cytochrome P450 enzyme implicated in autosomal recessive primary congenital glaucoma (PCG). The mechanism and function of CYP1B1 in the development of the PCG phenotype is unknown. Previously, investigators have reported detection of Cyp1b1 mRNA in the ciliary body and epithelium and neuroepithelium in the developing mouse eye, employing in situ hybridization techniques. Similarly, additional investigators have detected CYP1B1 mRNA in the iris, ciliary body, non-pigmented ciliary epithelial line, cornea, retinal-pigment epithelium, and retina in the human adult eye, using Northern blotting. This study was designed to immunolocalize CYP1B1 protein in the various ocular structures of normal, human fetal and adult eyes. Normal fetal and adult eyes were immunolabeled with a polyclonal antibody against human CYP1B1 using indirect immunofluorescence, and then compared with appropriate controls. The intensity of immunolabeling of the various ocular structures was assessed by qualitative and semi-quantitative techniques. In the anterior segment anti-CYP1B1 immunoreactivity (IR) was detected early in fetal development in the primitive ciliary epithelium. As well, the most intense CYP1B1 IR was in the non-pigmented ciliary epithelium. In addition, CYP1B1 IR was also present in the corneal epithelium and keratocytes, both layers of the iris pigmented epithelium, and retina. However, CYP1B1 IR was absent in the trabecular meshwork in all of the samples. In general, CYP1B1 immunolabeling in the human fetal eyes was more intense when compared to adult eyes. CYP1B1 IR was primarily immunolocalized to the non-pigmented ciliary epithelium and early in fetal development. In addition, CYP1B1 IR was not detected in the trabecular meshwork. These findings suggest that the abnormalities in the development of the trabecular meshwork in PCG may result from diminished or absent metabolism of important endogenous substrates in the ciliary epithelium due to non-functional CYP1B1

  14. Cytochrome P450 CYP1B1 activity in renal cell carcinoma.

    PubMed

    McFadyen, M C E; Melvin, W T; Murray, G I

    2004-08-31

    Renal cell carcinoma (RCC) is the most common malignancy of the kidney and has a poor prognosis due to its late presentation and resistance to current anticancer drugs. One mechanism of drug resistance, which is potentially amenable to therapeutic intervention, is based on studies in our laboratory. CYP1B1 is a cytochrome P450 enzyme overexpressed in a variety of malignant tumours. Our studies are now elucidating a functional role for CYP1B1 in drug resistance. Cytochrome P450 reductase (P450R) is required for optimal metabolic activity of CYP1B1. Both CYP1B1 and P450R can catalyse the biotransformation of anticancer drugs at the site of the tumour. In this investigation, we determined the expression of CYP1B1 and P450R in samples of normal kidney and RCC (11 paired normal and tumour and a further 15 tumour samples). The O-deethylation of ethoxyresorufin to resorufin was used to measure CYP1B1 activity in RCC. Cytochrome P450 reductase activity was determined by following the reduction of cytochrome c at 550 nm. The key finding of this study was the presence of active CYP1B1 in 70% of RCC. Coincubation with the CYP1B1 inhibitor alpha-naphthoflavone (10 nM) inhibited this activity. No corresponding CYP1B1 activity was detected in any of the normal tissue examined (n=11). Measurable levels of active P450R were determined in all normal (n=11) and tumour samples (n=26). The presence of detectable CYP1B1, which is capable of metabolising anticancer drugs in tumour cells, highlights a novel target for therapeutic intervention.

  15. Subtyping of Y-chromosomal haplogroup E-M78 (E1b1b1a) by SNP assay and its forensic application.

    PubMed

    Caratti, S; Gino, S; Torre, C; Robino, C

    2009-07-01

    The continual discovery of new single-nucleotide polymorphisms (SNPs) has led to an increased resolution of the Y chromosome phylogeny. Some of these Y-SNPs have shown to be restricted to small geographical regions and therefore may prove useful in the forensic field as tools for the prediction of population of origin of unknown casework samples. Here, we describe a system for the molecular dissection of haplogroup E-M78 (E1b1b1a), consisting of multiplex polymerase chain reaction and minisequencing of M78 and nine population-informative Y-SNPs (M148, M224, V12, V13, V19, V22, V27, V32, V65) in a single reaction. Sensitivity and admixture studies demonstrated that the SNP protocol allows robust genotyping from as little as 50 pg of male DNA, even in the presence of 500-fold amounts of female DNA. In order to evaluate the suitability of E1b1b1a, subhaplogrouping for population-of-origin prediction, the distribution of E-M78 and its derived variants was determined in an Italian population sample (n = 326).

  16. Pathogenesis-Related Protein 1b1 (PR1b1) Is a Major Tomato Fruit Protein Responsive to Chilling Temperature and Upregulated in High Polyamine Transgenic Genotypes

    PubMed Central

    Fatima, Tahira; Topuz, Muhamet; Bernadec, Anne; Sicher, Richard; Handa, Avtar K.; Mattoo, Autar K.

    2016-01-01

    Plants execute an array of mechanisms in response to stress which include upregulation of defense-related proteins and changes in specific metabolites. Polyamines – putrescine (Put), spermidine (Spd), and spermine (Spm) – are metabolites commonly found associated with abiotic stresses such as chilling stress. We have generated two transgenic tomato lines (556HO and 579HO) that express yeast S-adenosylmethionine decarboxylase and specifically accumulate Spd and Spm in fruits in comparison to fruits from control (556AZ) plants (Mehta et al., 2002). Tomato fruits undergo chilling injury at temperatures below 13°C. The high Spd and Spm tomato together with the control azygous line were utilized to address role(s) of polyamines in chilling-injury signaling. Exposure to chilling temperature (2°C) led to several-fold increase in the Put content in all the lines. Upon re-warming of the fruits at 20°C, the levels of Spd and Spm increased further in the fruit of the two transgenic lines, the higher levels remaining stable for 15 days after re-warming as compared to the fruit from the control line. Profiling their steady state proteins before and after re-warming highlighted a protein of ∼14 kD. Using proteomics approach, protein sequencing and immunoblotting, the ∼14-kD protein was identified as the pathogenesis related protein 1b1 (PR1b1). The PR1b1 protein accumulated transiently in the control fruit whose level was barely detectable at d 15 post-warming while in the fruit from both the 556HO and 579HO transgenic lines PR1b1 abundance increased and remained stable till d 15 post warming. PR1b1 gene transcripts were found low in the control fruit with a visible accumulation only on d 15 post warming; however, in both the transgenic lines it accumulated and increased soon after rewarming being several-fold higher on day 2 while in 556HO line this increase continued until d 6 than the control fruit. The chilling-induced increase in PR1b1 protein seems independent

  17. Genetic variation of Cytochrome P450 1B1 (CYP1B1) and risk of breast cancer among Polish women.

    PubMed

    Gaudet, Mia M; Chanock, Stephen; Lissowska, Jolanta; Berndt, Sonja I; Yang, Xiaohong Rose; Peplonska, Beata; Brinton, Louise A; Welch, Robert; Yeager, Meredith; Bardin-Mikolajczak, Alicja; Sherman, Mark E; Sutter, Thomas R; Garcia-Closas, Montserrat

    2006-08-01

    Four single nucleotide polymorphisms (SNPs) in CYP1B1 (Ex2 + 143 C > G, Ex2 + 356 G > T, Ex3 + 251 G > C, Ex3 + 315 A > G) cause amino acid changes (R48G, A119S, L432V and N453S, respectively) and are associated with increased formation of catechol estrogens; however, epidemiologic evidence only weakly supports an association between these variants and breast cancer risk. Because genetic variability conferring increased susceptibility could exist beyond these putative functional variants, we comprehensively examined the common genetic variability within CYP1B1. A total of eight haplotype-tagging (ht)SNPs (including Ex3 + 315 A > G), in addition to two putatively functional SNPs (Ex2 + 143 C > G and Ex3 + 251 G > C), were selected and genotyped in a large case-control study of Polish women (1995 cases and 2296 controls). Haplotypes were estimated using the expectation-maximization algorithm, and overall differences in the haplotype distribution between cases and controls were assessed using a global score test. We also evaluated levels of tumor CYP1B1 protein expression in a subset of 841 cases by immunohistochemistry, and their association with genetic variants. In the Polish population, we observed two linkage disequilibrium (LD)-defined blocks. Neither haplotypes (global P-value of 0.99 and 0.67 for each block of LD, respectively), nor individual SNPs (including three putatively functional SNPs) were associated with breast cancer risk. CYP1B1 was expressed in most tumor tissues (98%), and the level of expression was not related to the studied genetic variants. We found little evidence for modification of the estimated effect of haplotypes or individual SNPs by age, family history of breast cancer, or tumor hormone receptor status. The present study provides strong evidence against the existence of a substantial overall association between common genetic variation in CYP1B1 and breast cancer risk.

  18. Tobacco smoke induces CYP1B1 in the aerodigestive tract.

    PubMed

    Port, Jeffrey L; Yamaguchi, Kentaro; Du, Baoheng; De Lorenzo, Mariana; Chang, Mindy; Heerdt, Paul M; Kopelovich, Levy; Marcus, Craig B; Altorki, Nasser K; Subbaramaiah, Kotha; Dannenberg, Andrew J

    2004-11-01

    Several members of the P450 family, including cytochrome P450 1B1 (CYP1B1), can convert tobacco smoke (TS) procarcinogens, including benzo[a]pyrene (B[a]P), to carcinogenic intermediates. In this study we investigated the effects of TS condensate and B[a]P on the expression of CYP1B1 in vitro and in vivo. CYP1B1 mRNA and protein were induced by both TS condensate and B[a]P in cell lines derived from the human aerodigestive tract. Treatment with TS condensate stimulated binding of the aryl hydrocarbon receptor (AhR) to an oligonucleotide containing a canonical xenobiotic response element (XRE) site and induced XRE-luciferase activity. These findings are consistent with prior evidence that polycyclic aromatic hydrocarbons, known ligands of the AhR, stimulate CYP1B1 transcription by an XRE-dependent mechanism. To determine whether these in vitro findings applied in vivo, both murine and human studies were carried out. Short-term exposure to TS induced CYP1B1 in the tongue, esophagus, lung and colon of experimental mice. In contrast, CYP1B1 was not induced by TS in the aorta of these mice. Levels of CYP1B1 mRNA were also elevated in the bronchial mucosa of human tobacco smokers versus never smokers (P < 0.05). Taken together, these results support a role for CYP1B1 in TS-induced carcinogenesis in the aerodigestive tract.

  19. CYP1B1 expression in ovarian cancer in the laying hen Gallus domesticus

    PubMed Central

    Zhuge, Yan; Lagman, Jo Ann J.; Ansenberger, Kristine; Mahon, Cassandra J.; Daikoku, Takiko; Dey, Sudhansu K.; Bahr, Janice M.; Hales, Dale B.

    2009-01-01

    Objectives Ovarian carcinoma is the most lethal gynecological malignancy. The genetic and molecular mechanisms that cause it still remain largely unknown. CYP1B1 is a cytochrome P450 enzyme that catalyzes the conversion of estrogens to genotoxic catechol estrogens which may cause DNA mutations and initiate ovarian epithelial cancer. Our objectives were to evaluate CYP1B1 expression, distribution and localization in the hen ovary and to determine if there is an increased CYP1B1 expression associated with, and possibly involved in the initiation of ovarian cancer. Methods Two groups of hens were used: 1. young (50 weeks of age; devoid of cancer) and 2. old (165 weeks of age; divided into two groups: age-matched normal and ovarian cancer). CYP1B1 mRNA and protein expression were analyzed in cancerous ovaries, ovaries of age-matched normal and/or young hens by quantitative real-time PCR (qRT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC). RNA was extracted from tissue preserved in RNAlater for qRT-PCR. Tissue frozen in liquid nitrogen was used for ISH. Tissue fixed in neutral buffered formalin was subjected to IHC. Results Higher expression of CYP1B1 mRNA was observed in cancerous ovaries as compared to ovaries of young and age-matched normal hens by qRT-PCR. ISH and IHC confirmed that the expression of CYP1B1 was much higher in ovarian tumors compared to ovaries of age-matched normal hens. CYP1B1 mRNA and protein were distributed extensively throughout the carcinoma, while primarily localized to the granulosa layer surrounding the follicle in age-matched normal hens. IHC also showed nuclear localization of CYP1B1. Highly expressed CYP1B1 was found in POF-3 from young and age-matched normal hens as compared to POF-1 and POF-2 by qRT-PCR. No significant difference was found in the expression of CYP1B1 between the distal (site of rupture) and the proximal (site of attachment to the ovary) of POF-1 from young and age-matched normal hens. Conclusions High

  20. [Research progress on the relationship between SLCO1B1 gene and neonatal jaundice].

    PubMed

    Lu, An-Feng; Zhong, Dan-Ni

    2014-11-01

    Organic anion transporter 2 (OATP2) is an uptake transporter located on the basolateral membrane of human hepatocytes. It mediates the transportation of various organic solutes including bilirubin and impacts bilirubin metabolism. It is encoded by the gene of solute carrier organic anion transporter family member 1B1 and the gene variants that inhibit hepatic bilirubin uptake function may reduce the normal functional level of bilirubin elimination and result in neonatal hyperbilirubinemia. In recent years, some studies have indicated that variants of SLCO1B1 are associated with neonatal jaundice. This article reviews the research advance in SLCO1B1 with respect to the structure and function and the relationship between SLCO1B1 mutations and neonatal jaundice.

  1. Digenic Inheritance of Early-Onset Glaucoma: CYP1B1, a Potential Modifier Gene

    PubMed Central

    Vincent, Andrea L.; Billingsley, Gail; Buys, Yvonne; Levin, Alex V.; Priston, Megan; Trope, Graham; Williams-Lyn, Donna; Héon, Elise

    2002-01-01

    “Early-onset glaucoma” refers to genetically heterogeneous conditions for which glaucoma manifests at age 5–40 years and for which only a small subset is molecularly characterized. We studied the role of MYOC, CYP1B1, and PITX2 in a population (n=60) affected with juvenile or early-onset glaucoma from the greater Toronto area. By a combination of single-strand conformation polymorphism and direct cycle sequencing, MYOC mutations were detected in 8 (13.3%) of the 60 individuals, CYP1B1 mutations were detected in 3 (5%) of the 60 individuals, and no PITX2 mutations were detected. The range of phenotypic expression associated with MYOC and CYP1B1 mutations was greater than expected. MYOC mutations included cases of juvenile glaucoma with or without pigmentary glaucoma and mixed-mechanism glaucoma. CYP1B1 mutations involved cases of juvenile open-angle glaucoma, as well as cases of congenital glaucoma. The study of a family with autosomal dominant glaucoma showed the segregation of both MYOC and CYP1B1 mutations with disease; however, in this family, the mean age at onset of carriers of the MYOC mutation alone was 51 years (range 48–64 years), whereas carriers of both the MYOC and CYP1B1 mutations had an average age at onset of 27 years (range 23–38 years) (P=.001). This work emphasizes the genetic heterogeneity of juvenile glaucoma and suggests, for the first time, that (1) congenital glaucoma and juvenile glaucoma are allelic variants and (2) the spectrum of expression of MYOC and CYP1B1 mutations is greater than expected. We also propose that CYP1B1 may act as a modifier of MYOC expression and that these two genes may interact through a common pathway. PMID:11774072

  2. Role of CYP1B1 in PAH-DNA adduct formation and breast cancer risk

    SciTech Connect

    Goth-Goldstein, Regine; Russell, Marion L.; Muller, A.P.; Caleffi, M.; Eschiletti, J.; Graudenz, M.; Sohn, Michael D.

    2010-04-01

    This study investigated the hypothesis that increased exposure to polycyclic aromatic hydrocarbons (PAHs) increases breast cancer risk. PAHs are products of incomplete burning of organic matter and are present in cigarette smoke, ambient air, drinking water, and diet. PAHs require metabolic transformation to bind to DNA, causing DNA adducts, which can lead to mutations and are thought to be an important pre-cancer marker. In breast tissue, PAHs appear to be metabolized to their cancer-causing form primarily by the cytochrome P450 enzyme CYP1B1. Because the genotoxic impact of PAH depends on their metabolism, we hypothesized that high CYP1B1 enzyme levels result in increased formation of PAH-DNA adducts in breast tissue, leading to increased development of breast cancer. We have investigated molecular mechanisms of the relationship between PAH exposure, CYP1B1 expression and breast cancer risk in a clinic-based case-control study. We collected histologically normal breast tissue from 56 women (43 cases and 13 controls) undergoing breast surgery and analyzed these specimens for CYP1B1 genotype, PAH-DNA adducts and CYP1B1 gene expression. We did not detect any difference in aromatic DNA adduct levels of cases and controls, only between smokers and non-smokers. CYP1B1 transcript levels were slightly lower in controls than cases, but the difference was not statistically significant. We found no correlation between the levels of CYP1B1 expression and DNA adducts. If CYP1B1 has any role in breast cancer etiology it might be through its metabolism of estrogen rather than its metabolism of PAHs. However, due to the lack of statistical power these results should be interpreted with caution.

  3. Cytochrome P450 CYP1B1 over-expression in primary and metastatic ovarian cancer

    PubMed Central

    McFadyen, M C E; Cruickshank, M E; Miller, I D; McLeod, H L; Melvin, W T; Haites, N E; Parkin, D; Murray, G I

    2001-01-01

    Ovarian cancer is the most frequent cause of death from gynaecological malignancies world wide. Little improvement has been made in the long-term outcome of this disease, with the 5-year survival of patients only 30%. This poor prognosis is due to the late presentation of the disease and to the unpredictable response of ovarian cancer to chemotherapy. The cytochrome P450 enzymes are a superfamily of haemoproteins, known to be involved in the metabolic activation and/or detoxification of a number of anti-cancer drugs. CYP1B1 is a tumour-related form of cytochrome P450 which is over expressed in a wide variety of primary tumours of different histological type. The presence of CYP1B1 may be of importance in the modulation of these tumours to anti-cancer drugs. We have conducted a comprehensive immunohistochemical investigation, into the presence of cytochrome P450 CYP1B1 in primary and metastatic ovarian cancer. The key findings of this study are the increased expression of CYP1B1 in the majority of ovarian cancers investigated (92%), with a strong correlation demonstrated between CYP1B1 expression in both primary and metastatic ovarian cancer (P= 0.005 Spearman's rank correlation test). In contrast no detectable CYP1B1 was found in normal ovary. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11461084

  4. [Polymorphisms of CYP1B1 and COMT in breast and endometrial cancer].

    PubMed

    Zimarina, T C; Kristensen, V N; Imianitov, E N; Bershteĭn, L M

    2004-01-01

    CYP1B1 and COMT code for the key enzymes of catecholestrogen biosynthesis and metabolism, and their polymorphisms determine a variation of enzymic activities. RFLP analysis was used to study the allele and genotype frequency distributions of CYP1B1 polymorphisms Arg48Gly, Ala119Ser, and Val432Leu and COMT polymorphism Val158Met in 210 breast cancer patients, 138 endometrial cancer patients, and 152 healthy women. The COMT polymorphism showed no significant association with breast or endometrial cancer. For the first time, such association was observed for the CYP1B1 polymorphisms. CYP1B1 allele C (Arg48), which codes for the enzyme more active in estradiol 4-hydroxylation, was associated with higher risk of breast (OR = 3.22, CI 2.34-4.43, p = 0.000) and endometrial (OR = 2.43, CI 1.72-3.44, p = 0.000) cancer. Similar data were obtained for CYP1B1 allele G (Ala119): OR = 2.18, CI 1.58-3.01, p = 0.000 in breast cancer and OR = 2.52, CI 1.78-3.56, p = 0.000 in endometrial cancer. Risk of endometrial, but not breast, cancer was significantly higher in carriers of CYP1B1 genotype Val432/Val. This was explained by stronger estrogen dependence and, consequently, higher estrogen reactivity of the endometrium as compared with the mammary gland.

  5. Cytochrome P450 CYP1B1 over-expression in primary and metastatic ovarian cancer.

    PubMed

    McFadyen, M C; Cruickshank, M E; Miller, I D; McLeod, H L; Melvin, W T; Haites, N E; Parkin, D; Murray, G I

    2001-07-20

    Ovarian cancer is the most frequent cause of death from gynaecological malignancies world wide. Little improvement has been made in the long-term outcome of this disease, with the 5-year survival of patients only 30%. This poor prognosis is due to the late presentation of the disease and to the unpredictable response of ovarian cancer to chemotherapy. The cytochrome P450 enzymes are a superfamily of haemoproteins, known to be involved in the metabolic activation and/or detoxification of a number of anti-cancer drugs. CYP1B1 is a tumour-related form of cytochrome P450 which is over expressed in a wide variety of primary tumours of different histological type. The presence of CYP1B1 may be of importance in the modulation of these tumours to anti-cancer drugs. We have conducted a comprehensive immunohistochemical investigation, into the presence of cytochrome P450 CYP1B1 in primary and metastatic ovarian cancer. The key findings of this study are the increased expression of CYP1B1 in the majority of ovarian cancers investigated (92%), with a strong correlation demonstrated between CYP1B1 expression in both primary and metastatic ovarian cancer (P = 0.005 Spearman's rank correlation test). In contrast no detectable CYP1B1 was found in normal ovary.

  6. Three polymorphisms in cytochrome P450 1B1 (CYP1B1) gene and breast cancer risk: a meta-analysis.

    PubMed

    Economopoulos, Konstantinos P; Sergentanis, Theodoros N

    2010-07-01

    Cytochrome P450 1B1 (CYP1B1) is a P450 enzyme implicated in the metabolism of exogenous and endogenous substrates. The metabolism of polycyclic aromatic hydrocarbons and other procarcinogens through CYP1B1 may well lead to their activation. Apart from the extensively studied Val432Leu polymorphism, three single nucleotide polymorphisms in CYP1B1 have been studied concerning their potential implication in terms of breast cancer risk: Arg48Gly, Ala119Ser and Asn453Ser. This meta-analysis aims to examine whether the three aforementioned polymorphisms are associated with breast cancer risk. Eligible articles were identified by a search of MEDLINE bibliographical database for the period up to December 2009. Concerning Arg48Gly polymorphism, 10 studies were eligible (11,321 cases and 13,379 controls); 11 studies were eligible for Ala119Ser (10,715 cases and 11,678 controls); 12 cases were eligible regarding Asn453Ser (11,630 cases and 14,053 controls). Pooled odds ratios (OR) were appropriately derived form fixed-effects or random-effects models. Sensitivity analysis excluding studies whose genotype frequencies in controls significantly deviated from Hardy-Weinberg equilibrium was performed. Concerning Arg48Gly, the pooled ORs (95% CI) were 0.933 (0.808-1.078) for heterozygous and 0.819 (0.610-1.100) for homozygous Gly subjects. Regarding Ala119Ser, the pooled ORs were 0.992 (0.896-1.097) for heterozygous and 0.935 (0.729-1.198) for homozygous Ser subjects. With respect to Asn453Ser, the pooled ORs were 0.961 (0.906-1.019) for heterozygous and 0.984 (0.846-1.144) for homozygous Ser subjects. In conclusion, this meta-analysis suggests that CYP1B1 Arg48Gly, Ala119Ser and Asn453Ser polymorphisms are not associated with breast cancer risk. Studies on Chinese populations are needed, to elucidate race-specific effects on East Asian populations, if any.

  7. Analysis of CYP1B1 in pediatric and adult glaucoma and other ocular phenotypes

    PubMed Central

    Reis, Linda M.; Tyler, Rebecca C.; Weh, Eric; Hendee, Kathryn E.; Kariminejad, Ariana; Abdul-Rahman, Omar; Ben-Omran, Tawfeg; Manning, Melanie A.; Yesilyurt, Ahmet; McCarty, Catherine A.; Kitchner, Terrie E.; Costakos, Deborah

    2016-01-01

    Purpose The CYP1B1 gene encodes an enzyme that is a member of the cytochrome P450 superfamily. Mutations in CYP1B1 have been mainly reported in recessive pediatric ocular phenotypes, such as primary congenital glaucoma (PCG) and congenital glaucoma with anterior segment dysgenesis (CG with ASD), with some likely pathogenic variants also identified in families affected with adult-onset primary open angle glaucoma (POAG). Methods We examined CYP1B1 in 158 pediatric patients affected with PCG (eight), CG with ASD (22), CG with other developmental ocular disorders (11), juvenile glaucoma with or without additional ocular anomalies (26), and ASD or other developmental ocular conditions without glaucoma (91); in addition, a large cohort of adult patients with POAG (193) and POAG-negative controls (288) was examined. Results Recessive pathogenic variants in CYP1B1 were identified in two PCG pedigrees, three cases with CG and ASD, and two families with CG and other ocular defects, such as sclerocornea in one patient and microphthalmia in another individual; neither sclerocornea nor microphthalmia has been previously associated with CYP1B1. Most of the identified causative mutations are new occurrences of previously reported pathogenic alleles with two novel variants identified: a c.1325delC, p.(Pro442Glnfs*15) frameshift allele in a family with PCG and a c.157G>A, p.(Gly53Ser) variant identified in a proband with CG, Peters anomaly, and microphthalmia. Analysis of the family history in the CYP1B1-positive families revealed POAG in confirmed or presumed heterozygous relatives in one family with PCG and two families with ASD/CG; POAG was associated with the c.1064_1076del, p.(Arg355Hisfs*69) allele in two of these pedigrees. Screening of an unrelated POAG cohort identified the same c.1064_1076del heterozygous allele in one individual with sporadic POAG but not in age- and ethnicity-matched POAG-negative individuals. Overall, there was no significant enrichment for mutant

  8. Ultrafine carbon particles down-regulate CYP1B1 expression in human monocytes

    PubMed Central

    Eder, Christiane; Frankenberger, Marion; Stanzel, Franz; Seidel, Albrecht; Schramm, Karl-Werner; Ziegler-Heitbrock, Loems; Hofer, Thomas PJ

    2009-01-01

    Background Cytochrome P450 monoxygenases play an important role in the defence against inhaled toxic compounds and in metabolizing a wide range of xenobiotics and environmental contaminants. In ambient aerosol the ultrafine particle fraction which penetrates deeply into the lungs is considered to be a major factor for adverse health effects. The cells mainly affected by inhaled particles are lung epithelial cells and cells of the monocyte/macrophage lineage. Results In this study we have analyzed the effect of a mixture of fine TiO2 and ultrafine carbon black Printex 90 particles (P90) on the expression of cytochrome P450 1B1 (CYP1B1) in human monocytes, macrophages, bronchial epithelial cells and epithelial cell lines. CYP1B1 expression is strongly down-regulated by P90 in monocytes with a maximum after P90 treatment for 3 h while fine and ultrafine TiO2 had no effect. CYP1B1 was down-regulated up to 130-fold and in addition CYP1A1 mRNA was decreased 13-fold. In vitro generated monocyte-derived macrophages (MDM), epithelial cell lines, and primary bronchial epithelial cells also showed reduced CYP1B1 mRNA levels. Benzo[a]pyrene (BaP) is inducing CYB1B1 but ultrafine P90 can still down-regulate gene expression at 0.1 μM of BaP. The P90-induced reduction of CYP1B1 was also demonstrated at the protein level using Western blot analysis. Conclusion These data suggest that the P90-induced reduction of CYP gene expression may interfere with the activation and/or detoxification capabilities of inhaled toxic compounds. PMID:19835593

  9. Somatic overgrowth associated with homozygous mutations in both MAN1B1 and SEC23A

    PubMed Central

    Gupta, Swati; Fahiminiya, Somayyeh; Wang, Tracy; Dempsey Nunez, Laura; Rosenblatt, David S.; Gibson, William T.; Gilfix, Brian; Bergeron, John J. M.; Jerome-Majewska, Loydie A.

    2016-01-01

    Using whole-exome sequencing, we identified homozygous mutations in two unlinked genes, SEC23A c.1200G>C (p.M400I) and MAN1B1 c.1000C>T (p.R334C), associated with congenital birth defects in two patients from a consanguineous family. Patients presented with carbohydrate-deficient transferrin, tall stature, obesity, macrocephaly, and maloccluded teeth. The parents were healthy heterozygous carriers for both mutations and an unaffected sibling with tall stature carried the heterozygous mutation in SEC23A only. Mutations in SEC23A are responsible for craniolenticosultura dysplasia (CLSD). CLSD patients are short, have late-closing fontanels, and have reduced procollagen (pro-COL1A1) secretion because of abnormal pro-COL1A1 retention in the endoplasmic reticulum (ER). The mutation we identified in MAN1B1 was previously associated with reduced MAN1B1 protein and congenital disorders of glycosylation (CDG). CDG patients are also short, are obese, and have abnormal glycan remodeling. Molecular analysis of fibroblasts from the family revealed normal levels of SEC23A in all cells and reduced levels of MAN1B1 in cells with heterozygous or homozygous mutations in SEC23A and MAN1B1. Secretion of pro-COL1A1 was increased in fibroblasts from the siblings and patients, and pro-COL1A1 was retained in Golgi of heterozygous and homozygous mutant cells, although intracellular pro-COL1A1 was increased in patient fibroblasts only. We postulate that increased pro-COL1A1 secretion is responsible for tall stature in these patients and an unaffected sibling, and not previously discovered in patients with mutations in either SEC23A or MAN1B1. The patients in this study share biochemical and cellular characteristics consistent with mutations in MAN1B1 and SEC23A, indicating a digenic disease. PMID:27148587

  10. The CYP1B1 Leu432Val polymorphism and risk of urinary system cancers.

    PubMed

    Liu, Yi; Lin, Chang-sheng; Zhang, Ai-min; Song, Hua; Fan, Chang-chun

    2014-05-01

    The cytochrome P450 1B1 (CYP1B1) gene plays a key role in the metabolism of various carcinogens. The CYP1B1 Leu432Val polymorphism leads to leucine to valine substitution at codon 432. A lot of studies have shown that the CYP1B1 Leu432Val polymorphism was associated with urinary system cancers, especially prostate cancer. However, the results were still inconclusive. In this meta-analysis, by searching online databases and references of related reviews, we identified 17 eligible studies to assess the relationship between CYP1B1 Leu432Val polymorphism and urinary system cancers, including 7,783 cancer cases and 7,238 controls. By pooling all eligible studies, we found that the CYP1B1 Leu432Val polymorphism was not associated with overall urinary system cancers. However, in subgroup analyses, we found that the variant 432Val allele significantly increased the risk of prostate cancer (Val vs. Leu, odds ratio (OR) = 1.064, 95% confidence interval (CI) 0.981-1.154; Pheterogeneity = 0.002), while no association was found for bladder cancer (Val vs. Leu, OR = 0.942, 95% CI 0.853-1.041; Pheterogeneity = 0.504). No evidence of publication bias was found (Begg's test, P = 0.053; Egger's test, P = 0.073). In conclusion, based on 17 eligible studies, we found that the CYP1B1 Leu432Val polymorphism was associated with an increased risk of prostate cancer, while no association of bladder cancer was observed.

  11. Expression Profiling of CYP1B1 in Oral Squamous Cell Carcinoma: Counterintuitive Downregulation in Tumors

    PubMed Central

    Pradhan, Shalmali; Nagashri, M. N.; Gopinath, K. S.; Kumar, Arun

    2011-01-01

    Oral Squamous Cell Carcinoma (OSCC) has a very flagitious treatment regime. A prodrug approach is thought to aid in targeting chemotherapy. CYP1B1, a member of cytochrome P450 family, has been implicated in chemical carcinogenesis. There exists a general accordance that this protein is overexpressed in a variety of cancers, making it an ideal candidate for a prodrug therapy. The activation of the prodrug facilitated by CYP1B1 would enable the targeting of chemotherapy to tumor tissues in which CYP1B1 is specifically overexpressed as a result reducing the non-specific side effects that the current chemotherapy elicits. This study was aimed at validating the use of CYP1B1 as a target for the prodrug therapy in OSCC. The expression profile of CYP1B1 was analysed in a panel of 51 OSCC tumors, their corresponding normal tissues, an epithelial dysplasia lesion and its matched normal tissue by qRT-PCR, Western blotting and Immunohistochemistry. CYP1B1 was found to be downregulated in 77.78% (28/36) tumor tissues in comparison to their corresponding normal tissues as well as in the epithelial dysplasia lesion compared to its matched normal tissue at the transcriptional level, and in 92.86% (26/28) of tumor tissues at the protein level. This report therefore clearly demonstrates the downregulation of CYP1B1 at the transcriptional and translational levels in tumor tissues in comparison to their corresponding normal tissues. These observations indicate that caution should be observed as this therapy may not be applicable universally to all cancers and also suggest the possibility of a prophylactic therapy for oral cancer. PMID:22114726

  12. Expression profiling of CYP1B1 in oral squamous cell carcinoma: counterintuitive downregulation in tumors.

    PubMed

    Pradhan, Shalmali; Nagashri, M N; Gopinath, K S; Kumar, Arun

    2011-01-01

    Oral Squamous Cell Carcinoma (OSCC) has a very flagitious treatment regime. A prodrug approach is thought to aid in targeting chemotherapy. CYP1B1, a member of cytochrome P450 family, has been implicated in chemical carcinogenesis. There exists a general accordance that this protein is overexpressed in a variety of cancers, making it an ideal candidate for a prodrug therapy. The activation of the prodrug facilitated by CYP1B1 would enable the targeting of chemotherapy to tumor tissues in which CYP1B1 is specifically overexpressed as a result reducing the non-specific side effects that the current chemotherapy elicits. This study was aimed at validating the use of CYP1B1 as a target for the prodrug therapy in OSCC. The expression profile of CYP1B1 was analysed in a panel of 51 OSCC tumors, their corresponding normal tissues, an epithelial dysplasia lesion and its matched normal tissue by qRT-PCR, Western blotting and Immunohistochemistry. CYP1B1 was found to be downregulated in 77.78% (28/36) tumor tissues in comparison to their corresponding normal tissues as well as in the epithelial dysplasia lesion compared to its matched normal tissue at the transcriptional level, and in 92.86% (26/28) of tumor tissues at the protein level. This report therefore clearly demonstrates the downregulation of CYP1B1 at the transcriptional and translational levels in tumor tissues in comparison to their corresponding normal tissues. These observations indicate that caution should be observed as this therapy may not be applicable universally to all cancers and also suggest the possibility of a prophylactic therapy for oral cancer.

  13. CYP1B1 polymorphisms and k-ras mutations in patients with pancreatic ductal adenocarcinoma.

    PubMed

    Crous-Bou, Marta; De Vivo, Immaculata; Porta, Miquel; Pumarega, José A; López, Tomàs; Alguacil, Joan; Morales, Eva; Malats, Núria; Rifà, Juli; Hunter, David J; Real, Francisco X

    2008-05-01

    The frequency of CYP1B1 polymorphisms in pancreatic cancer has never been reported. There is also no evidence on the relationship between CYP1B1 variants and mutations in ras genes (K-, H- or N-ras) in any human neoplasm. We analyzed the following CYP1B1 polymorphisms in 129 incident cases of pancreatic ductal adenocarcinoma (PDA): the m1 allele (Val to Leu at codon 432) and the m2 allele (Asn to Ser at codon 453). The calculated frequencies for the m1 Val and m2 Asn alleles were 0.45 and 0.68, respectively. CYP1B1 genotypes were out of Hardy-Weinberg equilibrium; this was largely due to K-ras mutated PDA cases. The Val/Val genotype was over five times more frequent in PDA cases with a K-ras mutation than in wild-type cases (OR = 5.25; P = 0.121). In PDA, polymorphisms in CYP1B1 might be related with K-ras activation pathways.

  14. Cancer Activation and Polymorphisms of Human Cytochrome P450 1B1

    PubMed Central

    Chun, Young-Jin; Kim, Donghak

    2016-01-01

    Human cytochrome P450 enzymes (P450s, CYPs) are major oxidative catalysts that metabolize various xenobiotic and endogenous compounds. Many carcinogens induce cancer only after metabolic activation and P450 enzymes play an important role in this phenomenon. P450 1B1 mediates bioactivation of many procarcinogenic chemicals and carcinogenic estrogen. It catalyzes the oxidation reaction of polycyclic aromatic carbons, heterocyclic and aromatic amines, and the 4-hydroxylation reaction of 17β-estradiol. Enhanced expression of P450 1B1 promotes cancer cell proliferation and metastasis. There are at least 25 polymorphic variants of P450 1B1 and some of these have been reported to be associated with eye diseases. In addition, P450 1B1 polymorphisms can greatly affect the metabolic activation of many procarcinogenic compounds. It is necessary to understand the relationship between metabolic activation of such substances and P450 1B1 polymorphisms in order to develop rational strategies for the prevention of its toxic effect on human health. PMID:27123158

  15. Association of CYP1B1 with hypersensitivity induced by taxane therapy in breast cancer patients.

    PubMed

    Rizzo, Roberta; Spaggiari, Federica; Indelli, Monica; Lelli, Giorgio; Baricordi, Olavio R; Rimessi, Paola; Ferlini, Alessandra

    2010-11-01

    Taxanes represent a group of anticancer drugs with a wide range of activity against breast cancer. Therapy side effects include haematologic toxicity (neutropenia, leucopenia), peripheral neuropathy and hypersensitivity, and demonstrate inter-individual variations. Since it is known that three genes are implicated in taxane turnover, namely ABCB1 in the transport, CYP2C8 in the metabolism and CYP1B1 in the activity, we explored the association among polymorphisms (single nucleotide polymorphisms, SNPs) in these three genes and the occurrence of taxane-induced toxicity. We studied 95 patients affected by breast cancer and under treatment with taxanes as adjuvant, metastatic or neo-adjuvant therapy. We genotyped them for SNPs in the CYP2C8 (alleles *1, *2, *3 and *4), CYP1B1 (alleles *1 and *3) and ABCB1 (1236 C>T; 2677 G>T/A; 3435 C>T) genes by real-time PCR assay. We observed a significant association between the CYP1B1*3 allele and a lower occurrence of hypersensitivity reactions to taxane treatment. We speculate that the highest production of 4-hydroxyestradiol (4-OHE2) metabolite by CYP1B1*3 allele could increase the formation of the 4-OHE2-taxane adduct and possibly inhibit taxane toxicity. We suggest that CYP1B1 might affect taxane hypersensitivity therefore representing, if confirmed in a large cohort of patients, an exploratory hypersensitivity predictive biomarker.

  16. Association of CYP1B1 haplotypes and breast cancer risk in Caucasian women

    PubMed Central

    Huang, Yifan; Trentham-Dietz, Amy; García-Closas, Montserrat; Newcomb, Polly A.; Titus-Ernstoff, Linda; Hampton, John M.; Chanock, Stephen J.; Haines, Jonathan L.; Egan, Kathleen M.

    2009-01-01

    CYP1B1 is a key enzyme involved in estrogen metabolism and may play an important role in the development and progression of breast cancer. In a population-based case-control study, we examined eight CYP1B1 haplotype-tagging single nucleotide polymorphisms (htSNPs) in relation to invasive breast cancer risk. Analyses were based on 1,655 cases and 1,470 controls; all women were Caucasian. Among the individual SNPs, one (rs9341266) was associated with increased risk of breast cancer (ptrend = 0.021), although the association was no longer significant after adjusting for multiple tests. A marginally significant haplotype effect was identified (pglobal = 0.015), with significant associations identified for 2 uncommon haplotypes comprising 4% of the controls. Results suggest that genetic variation in CYP1B1 has at most a minor influence on breast cancer susceptibility among Caucasian women. PMID:19293312

  17. Association of CYP1B1 haplotypes and breast cancer risk in Caucasian women.

    PubMed

    Huang, Yifan; Trentham-Dietz, Amy; García-Closas, Montserrat; Newcomb, Polly A; Titus-Ernstoff, Linda; Hampton, John M; Chanock, Stephen J; Haines, Jonathan L; Egan, Kathleen M

    2009-04-01

    CYP1B1 is a key enzyme involved in estrogen metabolism and may play an important role in the development and progression of breast cancer. In a population-based case-control study, we examined eight CYP1B1 haplotype-tagging single nucleotide polymorphisms in relation to invasive breast cancer risk. Analyses were based on 1,655 cases and 1,470 controls; all women were Caucasian. Among the individual single nucleotide polymorphisms, one (rs9341266) was associated with increased risk of breast cancer (P(trend) = 0.021), although the association was no longer significant after adjusting for multiple tests. A marginally significant haplotype effect was identified (P(global) = 0.015), with significant associations identified for 2 uncommon haplotypes comprising 4% of the controls. Results suggest that genetic variation in CYP1B1 has at most a minor influence on breast cancer susceptibility among Caucasian women.

  18. Rare versus common variants in pharmacogenetics: SLCO1B1 variation and methotrexate disposition.

    PubMed

    Ramsey, Laura B; Bruun, Gitte H; Yang, Wenjian; Treviño, Lisa R; Vattathil, Selina; Scheet, Paul; Cheng, Cheng; Rosner, Gary L; Giacomini, Kathleen M; Fan, Yiping; Sparreboom, Alex; Mikkelsen, Torben S; Corydon, Thomas J; Pui, Ching-Hon; Evans, William E; Relling, Mary V

    2012-01-01

    Methotrexate is used to treat autoimmune diseases and malignancies, including acute lymphoblastic leukemia (ALL). Inter-individual variation in clearance of methotrexate results in heterogeneous systemic exposure, clinical efficacy, and toxicity. In a genome-wide association study of children with ALL, we identified SLCO1B1 as harboring multiple common polymorphisms associated with methotrexate clearance. The extent of influence of rare versus common variants on pharmacogenomic phenotypes remains largely unexplored. We tested the hypothesis that rare variants in SLCO1B1 could affect methotrexate clearance and compared the influence of common versus rare variants in addition to clinical covariates on clearance. From deep resequencing of SLCO1B1 exons in 699 children, we identified 93 SNPs, 15 of which were non-synonymous (NS). Three of these NS SNPs were common, with a minor allele frequency (MAF) >5%, one had low frequency (MAF 1%-5%), and 11 were rare (MAF <1%). NS SNPs (common or rare) predicted to be functionally damaging were more likely to be found among patients with the lowest methotrexate clearance than patients with high clearance. We verified lower function in vitro of four SLCO1B1 haplotypes that were associated with reduced methotrexate clearance. In a multivariate stepwise regression analysis adjusting for other genetic and non-genetic covariates, SLCO1B1 variants accounted for 10.7% of the population variability in clearance. Of that variability, common NS variants accounted for the majority, but rare damaging NS variants constituted 17.8% of SLCO1B1's effects (1.9% of total variation) and had larger effect sizes than common NS variants. Our results show that rare variants are likely to have an important effect on pharmacogenetic phenotypes.

  19. CYP1B1 gene mutations causing primary congenital glaucoma in Tunisia.

    PubMed

    Bouyacoub, Yosra; Ben Yahia, Salim; Abroug, Nesrine; Kahloun, Rim; Kefi, Rym; Khairallah, Moncef; Abdelhak, Sonia

    2014-07-01

    Primary congenital glaucoma (PCG) is responsible for a significant proportion of childhood blindness in Tunisia. Early prevention based on genetic diagnosis is therefore required. This study sought to determine the frequency of CYP1B1 (cytochrome P450, family 1, subfamily B, polypeptide 1) mutations in 18 PCG patients, recruited from Central and Southern of Tunisia. Genomic DNA was extracted and the coding regions of CYP1B1 were analysed by direct sequencing. A phylogenetic network of CYP1B1 haplotypes was drawn using the median-joining algorithm. Sequence analysis revealed a "tetra-allelic mutation" (two novel mutations, p.F231I and p.P437A in the homozygous state) in one patient. The healthy members of his family carried those variations on the same allele. Two previously described mutations p.G61E and c.535delG were also identified in the homozygous state in seven and two probands, respectively. Seven single-nucleotide polymorphisms were identified and used to generate haplotypes. Our results showed that the CYP1B1 mutations were present in 55% of Tunisian PCG patients' alleles. Haplotype analysis allowed us to define the proto-haplotype and to confirm historical migratory flows. Establishment of PCG genetic aetiology in Tunisia will improve genetic diagnosis and counselling.

  20. A polymorphism in the CYP1B1 promoter is functionally associated with primary congenital glaucoma.

    PubMed

    Chakrabarti, Subhabrata; Ghanekar, Yashoda; Kaur, Kiranpreet; Kaur, Inderjeet; Mandal, Anil K; Rao, Kollu N; Parikh, Rajul S; Thomas, Ravi; Majumder, Partha P

    2010-10-15

    Primary congenital glaucoma (PCG) is a childhood autosomal-recessive disorder caused by developmental defects in the trabecular meshwork and anterior chamber angle. These defects cause raised intraocular pressure (IOP) that damages the optic nerve and if left untreated, results in irreversible blindness. Mutations in CYP1B1 gene at the GLC3A locus (2p21) are associated with PCG. However, there has been very limited exploration of its promoter region. We resequenced the CYP1B1 promoter in a large cohort (n = 835) that included patients with PCG (n = 301), other primary glaucomas (primary open-angle glaucoma: n = 115 and primary angle closure glaucoma: n = 100) and unaffected controls (n = 319). We functionally characterized one associated variant by luciferase reporter assay using the trabecular meshwork (TM3) cell line. We found evidence of strong (P = 6.01 × 10(-4)) association of rs2567206 (T2805C) SNP in PCG and not in other primary glaucomas. Luciferase assay indicated a ∼90% reduction in CYP1B1 promoter activity in the risk-allele (C) compared to the other allele (T). The association of the risk allele was stronger in cases harboring homozygous CYP1B1 mutations (P = 3.42 × 10(-12)). The risk haplotype 'C-C-G' in the promoter had a strong non-random association to the previously characterized risk haplotype 'C-G-G-T-A' in the coding region. The independent effect of genotype at the promoter T2805C locus (P = 0.001), and the interaction effect of genotypes at the promoter and coding region mutations loci (P = 0.001) were significant for the presenting IOP of the worst affected eye. This is the first study that unequivocally shows the functional involvement of a CYP1B1 promoter variant in PCG.

  1. Cytochrome P450 1B1 polymorphisms and risk of renal cell carcinoma in men.

    PubMed

    Chang, Inik; Fukuhara, Shinichiro; Wong, Darryn K; Gill, Ankurpreet; Mitsui, Yozo; Majid, Shahana; Saini, Sharanjot; Yamamura, Soichiro; Chiyomaru, Takeshi; Hirata, Hiroshi; Ueno, Koji; Arora, Sumit; Shahryari, Varahram; Deng, Guoren; Tabatabai, Z Laura; Greene, Kirsten L; Shin, Dong Min; Enokida, Hideki; Shiina, Hiroaki; Nonomura, Norio; Dahiya, Rajvir; Tanaka, Yuichiro

    2014-10-01

    The cytochrome P450 1B1 (CYP1B1) enzyme activates xenobiotics to reactive forms as well as convert estradiol to 4-hydroxy-estradiol that has been shown to play a role in the carcinogenesis process of the kidney in male but not female animals. Prior reports show polymorphic variants of CYP1B1 to alter catalytic activity, and thus, we hypothesize that polymorphisms of the CYP1B1 gene are involved in the malignant transformation of the renal cell in men. The genetic distributions of five CYP1B1 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism in 480 normal healthy subjects and 403 sporadic renal cell carcinoma cases. All subjects were Caucasian men. The sites evaluated were codons 48 (C → G, Arg → Gly, rs10012), 119 (G → T, Ala → Ser, rs1056827), 432 (C → G, Leu → Val, rs1056836), 449 (C → T, Asp, rs1056837), and 453 (A → G, Asn → Ser, rs1800440). A trend was demonstrated for the 432 Val/Val (χ2, P = 0.06) and 449 T/T (χ2, P = 0.1) genotypes to play a protective role against renal cancer. Odds ratio (95 % confidence interval) for Val/Val compared to Leu/Leu at codon 432 was 0.65 (0.44-0.95) and T/T compared to C/C at codon 449 was 0.67 (0.45-0.99). Codons 432 and 449 were observed to be linked (D = 0.24), and haplotype involving 432 Val and 449 T was significantly reduced in cancer cases (P = 0.04). No association was found, however, when analyzing polymorphic sites with clinical stage of cancer. These results demonstrate polymorphisms of CYP1B1 to be associated with renal carcinogenesis and are of importance in understanding their role in the pathogenesis of renal cell carcinoma.

  2. Association between CYP1B1 Gene Polymorphisms and Risk Factors and Susceptibility to Laryngeal Cancer

    PubMed Central

    Yu, Peng-Ju; Chen, Wei-Guan; Feng, Quan-Lin; Chen, Wei; Jiang, Man-Jie; Li, Ze-Qing

    2015-01-01

    Background The aim of this study was to investigate the association between polymorphism of the cytochrome P450 1B1 (CYP1B1) gene, a metabolic enzyme gene, and the susceptibility to laryngeal cancer among the Chinese Han population. Material/Methods In a case-control study, we investigated polymorphisms in the CYP1B1 gene (rs10012, rs1056827, and rs1056836) with a real-time quantitative polymerase chain reaction (PCR) assay (TaqMan). The study was conducted with 300 Chinese Han patients with laryngeal cancer and 300 healthy Chinese Han subjects in a control group. We also studied the interactions between genetic polymorphism and risk factors such as smoking and alcohol consumption in the pathogenesis of laryngeal cancer. Results There were statistically significant differences in the distributions of the rs1056827 and rs1056836 genotypes between the 2 groups. Regarding rs1056827, carriers of the T allele had a significantly higher risk of laryngeal cancer than the G-allele carriers (OR=1.4339, 95% CI: 1.1268–1.8247; P=0.0034). The difference was still statistically significant after adjusting for factors such as age, sex, smoking, and drinking (adjusted OR=1.743, 95% CI: 1.124–3.743, P<0.001). However, regarding rs1056836, the G allele carriers had a significantly lower risk of laryngeal cancer than the C allele carriers (OR=0.5557, 95% CI: 0.3787–0.8154; P=0.0027). The difference was statistically significant even after adjusting for factors such as age, sex, smoking, and drinking (adjusted OR=0.5641, 95% CI: 0.3212–0.8121, P=0.001). Subjects who carry the C-T-C haplotype have a significantly increased incidence of laryngeal cancer. We also found that CYP1B1 rs1056827 polymorphism had synergistic effects with smoking or alcohol consumption regarding the risk of laryngeal cancer. Conclusions CYP1B1 gene polymorphism is closely related to the onset of laryngeal cancer. There is a mutually synergistic effect between smoking, alcohol consumption, and CYP1B1

  3. CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer

    DTIC Science & Technology

    2005-06-01

    AD Award Number: W81XWH-04-1-0579 TITLE: CYP1B1 Polymorphism as a Risk Factor for Race-Related Prostate Cancer PRINCIPAL INVESTIGATOR: Yuichiro...2005 Annual 1 Jun 2004 - 31 May 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER CYP IB I Polymorphism as a Risk Factor for Race-Related Prostate Cancer...Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT- SEE ATTACHED PAGE 15. SUBJECT TERMS CYPIBI, Polymorphism

  4. CYP1B1 Asn453Ser polymorphism and colorectal cancer risk: a meta-analysis.

    PubMed

    Mei, Qiang; Zhou, Daijun; Han, Jialong; Lu, Hai; Tang, Bo

    2012-09-01

    Studies investigating the association between cytochrome P450 1B1 (CYP1B1) Asn453Ser (453 A/G, rs1800440) polymorphism and colorectal cancer (CRC) risk report conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline and Embase Databases. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for CYP1B1 polymorphism and CRC were calculated in a fixed-effects model (the Mantel-Haenszel method) and a random-effects model (the DerSimonian and Laird method) when appropriate. The pooled ORs were performed for co-dominant model (GG vs AA, GA vs AA), dominant model (GG+GA vs AA), and recessive model (GG vs GA+AA). This meta-analysis included 7 case-control studies, which included 6375 CRC cases and 7003 controls. Overall, the variant genotypes (GG and GA) of the 453 A/G were not associated with CRC risk when compared with the wild-type AA homozygote (GG vs AA, OR=0.94, 95% CI=0.77-1.14; GA vs AA, OR=0.99, 95% CI=0.87-1.12). Similarly, no associations were found in the dominant and recessive models (dominant model, OR=0.98, 95% CI=0.87-1.09; recessive model, OR=0.94, 95% CI=0.77-1.14). When stratifying for country, study sample size, matched control and source of controls, no evidence of significant association was observed in any subgroup, except among those studies from "Canada". No publication bias was found in the present study. No association was found between the CYP1B1 Asn453Ser polymorphism and risk of CRC among Caucasians.

  5. Association between the CYP1B1 polymorphisms and risk of cancer: a meta-analysis.

    PubMed

    Liu, Jie-Ying; Yang, Yu; Liu, Zhi-Zhong; Xie, Jian-Jun; Du, Ya-Ping; Wang, Wei

    2015-04-01

    The previous, published data on the association between CYP1B1 polymorphisms and cancer risk remained controversial. To derive a more precise estimation of the association between the CYP1B1 polymorphisms and cancer risk, we performed a meta-analysis to investigate the association between cancer susceptibility and CYP1B1 Leu432Val, Asn453Ser, Arg48Gly, and Ala119Ser polymorphisms. For Asn453Ser and Arg48Gly polymorphisms, significantly decreased endometrial cancer was observed among Caucasians. For Ala119Ser polymorphism, we found that individuals with the minor variant genotypes had a high risk of prostate cancer. For Leu432Val polymorphism, we found that individuals with the minor variant genotypes had a higher risk of endometrial cancer and lung cancer and had a lower risk of ovarian cancer. In summary, this meta-analysis suggests that Leu432Val polymorphism is associated with ovarian cancer, lung cancer, and endometrial cancer risk; Asn453Ser and Arg48Gly polymorphisms are associated with endometrial cancer risk among Caucasians, Ala119Ser polymorphism is associated with prostate cancer risk, and Ala119Ser polymorphism is associated with breast cancer risk in Caucasians. In addition, our work also points out the importance of new studies for Ala119Ser polymorphism in endometrial cancer, because high heterogeneity was observed (I (2) > 75 %).

  6. Cytochrome P450 1B1 Contributes to the Development of Atherosclerosis and Hypertension in Apolipoprotein E-Deficient Mice.

    PubMed

    Song, Chi Young; Ghafoor, Khuzema; Ghafoor, Hafiz U; Khan, Nayaab S; Thirunavukkarasu, Shyamala; Jennings, Brett L; Estes, Anne M; Zaidi, Sahar; Bridges, Dave; Tso, Patrick; Gonzalez, Frank J; Malik, Kafait U

    2016-01-01

    Cytochrome P450 (CYP) 1B1 contributes to vascular smooth muscle cell growth and hypertension in male mice. This study was conducted to determine the contribution of CYP1B1 to the development of atherosclerosis and hypertension and associated pathogenesis in 8-week-old male apolipoprotein E-deficient (ApoE(-/-)/Cyp1b1(+/+)), and ApoE- and CYP1B1-deficient (ApoE(-/-)/Cyp1b1(-/-)) mice fed a normal or atherogenic diet for 12 weeks. A separate group of ApoE(-/-)/Cyp1b1(+/+) mice on an atherogenic diet was injected every third day with the CYP1B1 inhibitor, 2,3',4,5'-tetramethoxystilbene (300 μg/kg), or its vehicle, dimethyl sulfoxide (30 μL, IP); systolic blood pressure was measured by the tail cuff method. After 12 weeks, mice were euthanized, blood collected for lipid analysis, and aortas harvested for measuring lesions and remodeling, and for infiltration of inflammatory cells by histological and immunohistochemical analysis, respectively, and for reactive oxygen species production. Blood pressure, areas of lipids and collagen deposition, elastin breaks, infiltration of macrophages and T lymphocytes, reactive oxygen species generation in the aorta, and plasma lipid levels were increased in ApoE(-/-)/Cyp1b1(+/+) mice on an atherogenic diet; these changes were minimized in mice given 2,3',4,5'-tetramethoxystilbene, and in ApoE(-/-)/Cyp1b1(-/-) mice on an atherogenic diet; absorption/production of lipids remained unaltered in these mice. These data suggest that aortic lesions, hypertension, and associated pathogenesis in ApoE(-/-)/Cyp1b1(+/+) mice on an atherogenic diet are most likely dependent on CYP1B1-generated oxidative stress and increased plasma lipid levels independent of blood pressure and absorption of lipids. CYP1B1 could serve as a novel target for developing drugs to treat atherosclerosis and hypertension caused by hypercholesterolemia.

  7. CYP1B1 Polymorphisms and Susceptibility to Prostate Cancer: A Meta-Analysis

    PubMed Central

    Zhang, Hongtuan; Li, Liang; Xu, Yong

    2013-01-01

    Background Studies investigating the association between single-nucleotide polymorphisms (SNPs) of the cytochrome P450 1B1 (CYP1B1) and prostate cancer (PCa) risk report conflicting results. To derive a more precise estimation of the relationship between CYP1B1 polymorphisms and PCa risk, a meta-analysis was performed. Methodology/Principal Findings A comprehensive literature search was conducted to identify all eligible studies of CYP1B1 polymorphisms and PCa risk. A total of 14 independent studies, including 6380 cases and 5807 controls, were identified. We investigated by meta-analysis the effects of 5 polymorphisms in CYP1B1 L432V (12 studies, 5999 cases, 5438 controls), R48G (6 studies, 1647 cases, 1846 controls), N453S (4 studies, 1407 cases, 1499 controls), −13C/T (4 studies, 1116 cases, 1114 controls), and A119S (4 studies, 1057 cases, 1018 controls). There was no evidence that L432V had significant association with PCa in overall population. After subgroup analyses by ethnicity, we found that L432V was significantly associated with PCa risk in Asians (additive: OR = 2.38, 95%CI = 1.31-4.33, P = 0.004; recessive: OR = 2.11, 95%CI = 1.17–3.79, P = 0.01; dominant: OR = 1.52, 95%CI = 1.14–2.01, P = 0.004; allelic: OR = 1.52, 95%CI = 1.20–1.92, P = 0.0006). When stratified by source of controls, significantly elevated PCa risk was found in all genetic models in population based studies (additive: OR = 1.34, 95%CI = 1.14–1.57, P = 0.0003; recessive: OR = 1.25, 95%CI = 1.09–1.43, P = 0.002; dominant: OR = 1.25, 95%CI = 1.11–1.41, P = 0.0002; allelic: OR = 1.18, 95%CI = 1.09–1.28, P<0.0001). For N453S, there was a significant association between N453S polymorphism and PCa risk in both overall population (dominant: OR = 1.18, 95%CI = 1.00–1.38, P = 0.04) and mixed population (domiant: OR = 1.31, 95%CI = 1.06–1.63, P = 0.01; allelic

  8. Identification of the hepatic efflux transporters of organic anions using double-transfected Madin-Darby canine kidney II cells expressing human organic anion-transporting polypeptide 1B1 (OATP1B1)/multidrug resistance-associated protein 2, OATP1B1/multidrug resistance 1, and OATP1B1/breast cancer resistance protein.

    PubMed

    Matsushima, Soichiro; Maeda, Kazuya; Kondo, Chihiro; Hirano, Masaru; Sasaki, Makoto; Suzuki, Hiroshi; Sugiyama, Yuichi

    2005-09-01

    Until recently, it was generally believed that the transport of various organic anions across the bile canalicular membrane was mainly mediated by multidrug resistance-associated protein 2 (MRP2/ABCC2). However, a number of new reports have shown that some organic anions are also substrates of multidrug resistance 1 (MDR1/ABCB1) and/or breast cancer resistance protein (BCRP/ABCG2), implying MDR1 and BCRP could also be involved in the biliary excretion of organic anions in humans. In the present study, we constructed new double-transfected Madin-Darby canine kidney II (MDCKII) cells expressing organic anion-transporting polypeptide 1B1 (OATP1B1)/MDR1 and OATP1B1/BCRP, and we investigated the transcellular transport of four kinds of organic anions, estradiol-17beta-d-glucuronide (EG), estrone-3-sulfate (ES), pravastatin (PRA), and cerivastatin (CER), to identify which efflux transporters mediate the biliary excretion of compounds using double-transfected cells. We observed the vectorial transport of EG and ES in all the double transfectants. MRP2 showed the highest efflux clearance of EG among these efflux transporters, whereas BCRP-mediated clearance of ES was the highest in these double transfectants. In addition, two kinds of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, CER and PRA, were also substrates of all these efflux transporters. The rank order of the efflux clearance of PRA mediated by each transporter was the same as that of EG, whereas the contribution of MDR1 to the efflux of CER was relatively greater than for PRA. This experimental system is very useful for identifying which transporters are involved in the biliary excretion of organic anions that cannot easily penetrate the plasma membrane.

  9. Variant alleles of the CYP1B1 gene are associated with colorectal cancer susceptibility

    PubMed Central

    2010-01-01

    Background CYP1B1 is a P450 enzyme which is involved in the activation of pro-carcinogens to carcinogens as well as sex hormone metabolism. Because differences in the activity of the enzyme have been correlated with variant alleles of single nucleotide polymorphisms (SNPs), it represents an attractive candidate gene for studies into colorectal cancer susceptibility. Methods We genotyped 597 cancer patients and 597controls for three CYP1B1 SNPs, which have previously been shown to be associated with altered enzymatic activity. Using the three SNPs, eight different haplotypes were constructed. The haplotype frequencies were estimated in cases and controls and then compared. The odds ratio for each tumour type, associated with each haplotype was estimated, with reference to the most common haplotype observed in the controls. Results The three SNPs rs10012, rs1056827 and rs1056836 alone did not provide any significant evidence of association with colorectal cancer risk. Haplotypes of rs1056827 and rs10012 or rs1056827 and rs1056836 revealed an association with colorectal cancer which was significantly stronger in the homozygous carriers. One haplotype was under represented in the colorectal cancer patient group compared to the control population suggesting a protective effect. Conclusion Genetic variants within the CYP1B1 that are associated with altered function appear to influence susceptibility to a colorectal cancer in Poland. Three haplotypes were associated with altered cancer risk; one conferred protection and two were associated with an increased risk of disease. These observations should be confirmed in other populations. PMID:20701755

  10. Fentanyl pharmacokinetics is not dependent on hepatic uptake by organic anion-transporting polypeptide 1B1 in human beings.

    PubMed

    Ziesenitz, Victoria C; König, Sonja K; Mahlke, Nina; Jantos, Ricarda; Skopp, Gisela; Weiss, Johanna; Haefeli, Walter E; Mikus, Gerd

    2013-07-01

    A recent study investigating the pharmacokinetics of fentanyl in Sprague-Dawley rats suggested fentanyl to be a substrate of rat organic anion-transporting polypeptide Oatp. In human beings, the most important OATP for the pharmacokinetics of many drugs is OATP1B1. Therefore, genetic variants of OATP1B1 (SLCO1B1) might modulate fentanyl pharmacokinetics and efficacy in human beings. Sixteen healthy male and female volunteers, homozygous for SLCO1B1*1a (genetic wild-type) (n = 11) or *15 (deficient haplotype carrying the single-nucleotide polymorphisms rs2306283 and rs4149056 and exhibiting altered transport activity; n = 5), were included in this randomized crossover study. The participants received fentanyl (5 μg/kg) intravenously alone or with the OATP inhibitor rifampicin (600 mg single oral dose). The pharmacokinetics of fentanyl and norfentanyl were determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). In addition, fentanyl uptake in vitro was evaluated in OATP1B1 overexpressing HEK293 cells and compared to a mock-transfected cell line. In the clinical trial, fentanyl clearance was 18.8 ± 8.2 mL/min. kg in SLCO1B1*1a and 19.5 ± 1.8 mL/min/kg in SLCO1B1*15 carriers and not significantly different between the genotypes. During rifampicin, fentanyl clearance was 15.0 ± 4.4 mL/min/kg in SLCO1B1*1a and 16.7 ± 5.9 mL/min/kg in SLCO1B1*15 carriers (p > 0.5). In addition, in vitro data also indicate that fentanyl is not transported by OATP1B1. In conclusion, our data indicate that OATP1B1 has no impact on fentanyl pharmacokinetics in human beings.

  11. Interaction of CYP1B1, cigarette-smoke carcinogen metabolism, and lung cancer risk

    PubMed Central

    Church, Timothy R; Haznadar, Majda; Geisser, Mindy S; Anderson, Kristin E; Caporaso, Neil E; Le, Chap; Abdullah, Salwan B; Hecht, Stephen S; Oken, Martin M; Van Ness, Brian

    2010-01-01

    A previously published case-control study nested in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial found a significant relationship of serum levels of total NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides) to prospective lung cancer risk. The present paper examines this relationship in the context of single-nucleotide polymorphisms (SNPs) in genes important in the metabolism of tobacco smoke carcinogens. DNA was extracted from the subjects' lymphocytes and analyzed for SNPs in 11 locations on four genes related to tobacco carcinogen metabolism. Logistic regressions on case-control status were used to estimate main effects of SNPs and biomarkers and their interactions adjusting for potential confounders. Of the 11 SNPs, only one, in CYP1B1, significantly interacted with total NNAL affecting risk for lung cancer. At low NNAL levels, the variant appeared protective. However, for those with the minor variant, the risk for lung cancer increased with increasing NNAL five times as rapidly compared to those without it, so that at high NNAL levels, this SNP's protection disappears. Analyzing only adenocarcinomas, the effect of the variant was even stronger, with the risk of cancer increasing six times as fast. A common polymorphism of CYP1B1 may play a role in the risk of NNK, a powerful lung carcinogen, in the development of lung cancer in smokers. PMID:21532841

  12. The CYP1B1_1358_GG genotype is associated with estrogen receptor-negative breast cancer.

    PubMed

    Justenhoven, Christina; Pierl, Christiane B; Haas, Susanne; Fischer, Hans-Peter; Baisch, Christian; Hamann, Ute; Harth, Volker; Pesch, Beate; Brüning, Thomas; Vollmert, Caren; Illig, Thomas; Dippon, Jürgen; Ko, Yon-Dschun; Brauch, Hiltrud

    2008-09-01

    Cytochrome P450 1B1 (CYP1B1) is a major enzyme in the initial catabolic step of estradiol (E2) metabolism and belongs to the multitude of genes regulated by the estrogen receptor alpha (ERalpha). The common non-synonymous polymorphisms CYP1B1_1358_A>G and CYP1B1_1294_C>G increase CYP1B1 enzymatic activity. Given a relationship between CYP1B1 and breast tumor E2 level as well as E2 level and breast tumor ERalpha expression it is of interest to know whether CYP1B1 polymorphisms have an impact on the ERalpha status of breast cancer. We genotyped the GENICA population-based breast cancer case-control collection (1,021 cases, 1,015 controls) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and investigated in cases the association between genotypes and tumor ERalpha status (739 ERalpha positive cases; 212 ERalpha negative cases) by logistic regression. We observed a significant association between the homozygous variant CYP1B1_1358_GG genotype and negative ERalpha status (P = 0.005; OR 2.82, 95% CI: 1.37-5.82) with a highly significant Ptrend for CYP1B1_1358_A>G and negative ERalpha status (P = 0.003). We also observed an association of CYP1B1_1358_GG and negative PR status (P = 0.015; OR 2.36, 95% CI: 1.18-4.70) and a Ptrend of 0.111 for CYP1B1_1358_A>G and negative progesterone receptor (PR) status. We conclude that the CYP1B1_1358_A>G polymorphism has an impact on ERalpha status in breast cancer in that the CYP1B1_1358_GG genotype known to encode higher CYP1B1 activity is associated with ERalpha negativity.

  13. Association of single nucleotide polymorphisms in CYP1B1 and COMT genes with breast cancer susceptibility in Indian women.

    PubMed

    Yadav, Sharawan; Singhal, Naveen Kumar; Singh, Virendra; Rastogi, Neeraj; Srivastava, Pramod Kumar; Singh, Mahendra Pratap

    2009-01-01

    Cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) enzymes play critical roles in estrogen metabolism. Alterations in the catalytic activity of CYP1B1 and COMT enzymes have been found associated with altered breast cancer risk in postmenopausal women in many populations. The substitution of leucine (Leu) to valine (Val) at codon 432 increases the catalytic activity of CYP1B1, however, substitution of Val to methionine (Met) at codon 158 decreases the catalytic activity of COMT. The present study was performed to evaluate the associations of CYP1B1 Leu(432)Val and/or COMT Val(158)Met polymorphisms with total, premenopausal and postmenopausal breast cancer risks in Indian women. COMT and CYP1B1 polymorphisms in controls and breast cancer patients were analyzed employing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) followed by gel electrophoresis. Although CYP1B1 and COMT genotypes did not exhibit statistically significant association with breast cancer risks when analyzed individually, COMT wild type (Val(158)Val) in combination with CYP1B1 heterozygous variant (Leu(432)Val) [OR: 0.21; 95% CI (0.05-0.82), p value; 0.021] and COMT heterozygous variant (Val(158)Met) in combination with CYP1B1 wild type (Leu(432)Leu) [OR: 0.29; 95% CI (0.08-0.96), p value; 0.042] showed significant protective association with premenopausal breast cancer risk. The results demonstrate that CYP1B1 wild type in combination with COMT heterozygous or their inverse combination offer protection against breast cancer in premenopausal Indian women.

  14. Association of the CYP1B1*3 allele with survival in patients with prostate cancer receiving docetaxel.

    PubMed

    Sissung, Tristan M; Danesi, Romano; Price, Douglas K; Steinberg, Seth M; de Wit, Ronald; Zahid, Muhammad; Gaikwad, Nilesh; Cavalieri, Ercole; Dahut, William L; Sackett, Dan L; Figg, William D; Sparreboom, Alex

    2008-01-01

    Using a single nucleotide polymorphism association study in 52 men with prostate cancer receiving docetaxel, we found that individuals carrying two copies of the CYP1B1*3 polymorphic variant had a poor prognosis after docetaxel-based therapies compared with individuals carrying at least one copy of the CYP1B1*1 allele (30.6 versus 12.8 months; P=0.0004). The association between CYP1B1*3 and response to therapy was not observed in similar subjects receiving non-taxane-based therapy (P=0.18). The systemic clearance of docetaxel was also unrelated to CYP1B1 genotype status (P=0.39), indicating that the association of CYP1B1*3 with clinical response is not due to docetaxel metabolism. To explain these results, we hypothesized that an indirect gene-drug interaction was interfering with the primary mechanism of action of docetaxel, tubulin polymerization. We therefore conducted tubulin polymerization experiments with taxanes in the presence or absence of certain CYP1B1 estrogen metabolites, which are known to bind to nucleophilic sites in proteins and DNA, that revealed the primary estrogen metabolite of CYP1B1, 4-hydroxyestradiol (4-OHE2), when oxidized to estradiol-3,4-quinone strongly inhibits tubulin polymerization. The 4-OHE2 is also formed more readily by the protein encoded by the CYP1B1*3 allele, validating further our data in patients. Furthermore, estradiol-3,4-quinone reacted in vitro with docetaxel to form the 4-OHE2-docetaxel adduct. This pilot study provides evidence that CYP1B1*3 may be an important marker for estimating docetaxel efficacy in patients with prostate cancer. This link is likely associated with CYP1B1*3 genotype-dependent estrogen metabolism.

  15. Tag SNPs detect association of the CYP1B1 gene with primary open angle glaucoma

    PubMed Central

    Hewitt, Alex W.; Mackey, David A.; Mitchell, Paul; Craig, Jamie E.

    2010-01-01

    Purpose The cytochrome p450 family 1 subfamily B (CYP1B1) gene is a well known cause of autosomal recessive primary congenital glaucoma. It has also been postulated as a modifier of disease severity in primary open angle glaucoma (POAG), particularly in juvenile onset families. However, the role of common variation in the gene in relation to POAG has not been thoroughly explored. Methods Seven tag single nucleotide polymorphisms (SNPs), including two coding variants (L432V and N543S), were genotyped in 860 POAG cases and 898 examined normal controls. Each SNP and haplotype was assessed for association with disease. In addition, a subset of 396 severe cases and 452 elderly controls were analyzed separately. Results There was no association of any individual SNP in the full data set. Two SNPs (rs162562 and rs10916) were nominally associated under a dominant model in the severe cases (p<0.05). A common haplotype (AGCAGCC) was also found to be nominally associated in both the full data set (p=0.048, OR [95%CI]=0.83 [0.69–0.90]) and more significantly in the severe cases (p=0.004, OR [95%CI]=0.68 [0.52–0.89]) which survives correction for multiple testing. Conclusions Although no major effect of common variation at the CYP1B1 locus on POAG was found, there could be an effect of SNPs tagged by rs162562 and represented on the AGCAGCC haplotype. PMID:21139974

  16. HLA-DQA1/B1 alleles as putative susceptibility markers in congenital toxoplasmosis

    PubMed Central

    Shimokawa, Paulo Tadashi; Targa, Lília Spaleta; Yamamoto, Lidia; Rodrigues, Jonatas Cristian; Kanunfre, Kelly Aparecida; Okay, Thelma Suely

    2016-01-01

    ABSTRACT Host and parasite genotypes are among the factors associated with congenital toxoplasmosis pathogenesis. As HLA class II molecules play a key role in the immune system regulation, the aim of this study was to investigate whether HLA-DQA1/B1 alleles are associated with susceptibility or protection to congenital toxoplasmosis. One hundred and twenty-two fetuses with and 103 without toxoplasmosis were studied. The two study groups were comparable according to a number of socio-demographic and genetic variables. HLA alleles were typed by PCR-SSP. In the HLA-DQA1 region, the allele frequencies showed that *01:03 and *03:02 alleles could confer susceptibility (OR= 3.06, p = 0.0002 and OR= 9.60, p= 0.0001, respectively) as they were more frequent among infected fetuses. Regarding the HLA-DQB1 region, the *05:04 allele could confer susceptibility (OR = 6.95, p < 0.0001). Of the 122 infected fetuses, 10 presented susceptibility haplotypes contrasting with only one in the non-infected group. This difference was not statistically significant after correction for multiple comparison (OR = 9.37, p=0.011). In the casuistic, there were two severely damaged fetuses with high parasite loads determined in amniotic fluid samples and HLA-DQA1 susceptibility alleles. In the present study, a discriminatory potential of HLA-DQA1/B1 alleles to identify susceptibility to congenital toxoplasmosis and the most severe cases has been shown. PMID:26856406

  17. Influence of the Cyp1B1 L432V gene polymorphism and exposure to tobacco smoke on Cyp1B1 mRNA expression in human leukocytes.

    PubMed

    Helmig, Simone; Hadzaad, Bahar; Döhrel, Juliane; Schneider, Joachim

    2009-07-01

    Cytochrome P450 1B1 (CYP1B1), a phase I enzyme, is involved in the activation of a broad spectrum of procarcinogens. An association of the Cyp1B1 L432V polymorphism with diverse types of cancer, as well as an impact on the catalytic activity of the enzyme, has been described. To show the functional impact of the allelic variant Cyp1B1*3, we investigated the quantitative Cyp1B1 mRNA expression in a population of smokers, nonsmokers, and ex-smokers and determined their genotypes. Detection of the L432V polymorphism in exon 3 of the Cyp1B1 gene was performed by rapid capillary polymerase chain reaction (PCR) with melting curve analysis. For quantitative comparison of Cyp1B1 mRNA levels, real-time PCR was performed using SYBR Green fluorescence in a LightCycler system. Calculations of expression were made with the 2(-DeltaDeltaCT) method. In comparing relative Cyp1B1 mRNA expression, highly significant differences between the two homozygote genotypes *1/*1 and *3/*3 (0.185 +/- 0.027, n = 118 versus 0.071 +/- 0.013, n = 56; p = 0.000), as well as between the heterozygote genotype *1/*3 and the homozygote genotype *3/*3 (0.178 +/- 0.025, n = 171 versus 0.071 +/- 0.013, n = 56; p = 0.000), were revealed. Significant differences between the genotypes were also detected within the subgroups of smokers, nonsmokers, and ex-smokers. No significant differences were determined in comparing the relative Cyp1B1 mRNA expression with regard to tobacco smoke exposure. Our results suggest that genotypes carrying the C allele (*1/*1 and *1/*3) at Cyp1B1 L432V polymorphism have a significantly higher Cyp1B1 mRNA expression compared with the genotype without the C allele (*3/*3). Gene expression of Cyp1B1 mRNA cannot be used as a biomarker for exposure of tobacco smoke.

  18. Cytochrome P450 1B1 expression in rat esophageal tumorigenesis promoted by gastric and duodenal reflux.

    PubMed

    Devlin, Andrea H; McIlroy, Marie; McKeen, Hayley D; Bonde, Pramode; Menezes, A A Carlos; Swarbrick, Christine J; Robson, Tracy; Hirst, David G; Campbell, F Charles; McGuigan, James A; McKeown, Stephanie R

    2009-02-01

    Cytochrome P450 1B1 (CYP1B1) mRNA is constitutively expressed in most normal extra-hepatic tissues; however the protein is not detectable in these tissues but is expressed in a wide variety of tumors. CYP1B1 is responsible for the activation of a number of carcinogens present in tobacco smoke and food. A surgical model of rat esophageal tumorigenesis, promoted by gastric or duodenal reflux was used to determine CYP1B1 expression in premalignant esophageal tissue. Immunohistochemistry was performed using a modified amplified fluorescein tyramide protocol. CYP1B1 was not observed in normal esophageal mucosa, submucosa, or muscularis mucosa. Animals exposed to gastric reflux developed mild hyperplasia. Varying degrees of hyperplasia were observed in the duodenal reflux group. All regions of hyperplasia showed moderate or strong CYP1B1 immunoreactivity. Duodenal reflux induced a small number of premalignant changes: immunoreactivity was absent from the epithelium of squamous dysplasia (0/10), Barrett's esophagus (0/7), and majority of dysplastic Barrett's esophagus (1/4). Moderate or strong immunoreactivity was observed in the majority (7/8) of squamous cell carcinomas (SCCs) in situ. Immunoreactivity was also observed in the lamina propria and submucosa in association with inflammation, regardless of the severity of inflammation. The expression of CYP1B1 in hyperplasia, SCCs in situ, or in association with inflammation may increase the production of carcinogenic metabolites, which may promote esophageal tumorigenesis.

  19. CYP1B1 enhances the resistance of epithelial ovarian cancer cells to paclitaxel in vivo and in vitro

    PubMed Central

    ZHU, ZHUANGYAN; MU, YAQIN; QI, CAIXIA; WANG, JIAN; XI, GUOPING; GUO, JUNCHENG; MI, RUORAN; ZHAO, FUXI

    2015-01-01

    Ovarian cancer (OC) is the most frequent cause of mortality among gynecological malignancies, with a 5-year survival rate of approximately 30%. The standard regimen for OC therapy includes a platinum agent combined with a taxane, to which the patients frequently acquire resistance. Resistance arises from the oxidation of anticancer drugs by CYP1B1, a cytochrome P450 enzyme overexpressed in malignant OC. The aim of the present study was to determine the role of CYP1B1 expression in the drug resistance of OC to the taxane, paclitaxel (PTX). Immunohistochemical staining was used to assess CYP1B1 expression in a panel of ovarian samples (53 primary cancer samples, 14 samples of metastastic cancer, 30 benign tumor samples and 19 normal tissue samples). Semi-quantitative RT-PCR was also performed to determine CYP1B1 expression in several OC cell lines. Finally, we used proliferation and toxicity assays, as well as a mouse xenograft model using nude mice to determine whether α-naphthoflavone (ANF), a CYP1B1 specific inhibitor, reduces resistance to PTX. CYP1B1 was overexpressed in the samples from primary and metastatic loci of epithelial ovarian cancers. In some cell lines, PTX induced CYP1B1 expression, which resulted in drug resistance. Exposure to ANF reduced drug resistance and enhanced the sensitivity of OC cells to PTX in vitro and in vivo. The expression profile of CYP1B1 suggests that it has the potential to be a useful diagnostic marker and prognostic factor for malignant OC. The inhibition of CYP1B1 expression by specific agents may provide a novel therapeutic strategy for the treatment of patients resistant to PTX and may improve the prognosis of these patients. PMID:25516145

  20. Cytochrome P450 1B1 gene polymorphisms as predictors of anticancer drug activity: studies with in vitro models.

    PubMed

    Laroche-Clary, Audrey; Le Morvan, Valérie; Yamori, Takao; Robert, Jacques

    2010-12-01

    Cytochrome P450 1B1 (CYP1B1) is found in tumor tissue and is suspected to play a role in oncogenesis and drug resistance. CYP1B1 gene polymorphisms have been associated with the risk of developing lung and other cancers. They may be associated with tumor response to anticancer drugs. We have determined 4 frequent nonsynonymous gene polymorphisms of CYP1B1 in the human tumor cell lines panels of the National Cancer Institute (NCI) and the Japanese Foundation for Cancer Research (JFCR): rs10012 (R48G), rs1056827 (A119S), rs1056836 (L432V), and rs1800440 (N453S). Numerous anticancer drugs have been tested against these panels that offer the opportunity to detect associations between gene polymorphisms and drug sensitivity. CYP1B1 single nucleotide polymorphisms were in marked linkage disequilibrium. The L432V allelic variants were significantly associated with reduced sensitivity to DNA-interacting anticancer agents, alkylators, camptothecins, topoisomerase II inhibitors, and some antimetabolites. For instance, in the NCI panel, cell lines homozygous for the V432 allele were globally 2-fold resistant to alkylating agents (P = 5 × 10(-10)) and 4.5-fold to camptothecins (P = 6.6 × 10(-9)) than cell lines homozygous for the L432 allele. Similar features were exhibited by the JFCR panel. Cell lines homozygous for the V432 allele were globally less sensitive to DNA-interfering drugs than cell lines having at least 1 common allele. There was no significant association between mRNA expression of CYP1B1 and CYP1B1 genotype, and no significant association between CYP1B1 mRNA expression and drug cytotoxicity. These observations open the way to clinical studies exploring the role of CYP1B1 gene polymorphisms for predicting tumor sensitivity to chemotherapy.

  1. CYP1B1 enhances the resistance of epithelial ovarian cancer cells to paclitaxel in vivo and in vitro.

    PubMed

    Zhu, Zhuangyan; Mu, Yaqin; Qi, Caixia; Wang, Jian; Xi, Guoping; Guo, Juncheng; Mi, Ruoran; Zhao, Fuxi

    2015-02-01

    Ovarian cancer (OC) is the most frequent cause of mortality among gynecological malignancies, with a 5-year survival rate of approximately 30%. The standard regimen for OC therapy includes a platinum agent combined with a taxane, to which the patients frequently acquire resistance. Resistance arises from the oxidation of anticancer drugs by CYP1B1, a cytochrome P450 enzyme overexpressed in malignant OC. The aim of the present study was to determine the role of CYP1B1 expression in the drug resistance of OC to the taxane, paclitaxel (PTX). Immunohistochemical staining was used to assess CYP1B1 expression in a panel of ovarian samples (53 primary cancer samples, 14 samples of metastastic cancer, 30 benign tumor samples and 19 normal tissue samples). Semi-quantitative RT-PCR was also performed to determine CYP1B1 expression in several OC cell lines. Finally, we used proliferation and toxicity assays, as well as a mouse xenograft model using nude mice to determine whether α-naphthoflavone (ANF), a CYP1B1 specific inhibitor, reduces resistance to PTX. CYP1B1 was overexpressed in the samples from primary and metastatic loci of epithelial ovarian cancers. In some cell lines, PTX induced CYP1B1 expression, which resulted in drug resistance. Exposure to ANF reduced drug resistance and enhanced the sensitivity of OC cells to PTX in vitro and in vivo. The expression profile of CYP1B1 suggests that it has the potential to be a useful diagnostic marker and prognostic factor for malignant OC. The inhibition of CYP1B1 expression by specific agents may provide a novel therapeutic strategy for the treatment of patients resistant to PTX and may improve the prognosis of these patients.

  2. Aryl hydrocarbon hydroxylase represents CYP1B1, and not CYP1A1, in human freshly isolated white cells: trimodal distribution of Japanese population according to induction of CYP1B1 mRNA by environmental dioxins.

    PubMed

    Toide, Kenji; Yamazaki, Hiroshi; Nagashima, Rikako; Itoh, Keisuke; Iwano, Shunsuke; Takahashi, Yoshiki; Watanabe, Shaw; Kamataki, Tetsuya

    2003-03-01

    The expression level of mRNAs for cytochrome P450 (CYP) 1A1 and 1B1 in freshly prepared white cells from 72 subjects exposed to dioxins at waste incinerators was investigated. The amounts of CYP1B1 mRNA ranged from 0.16 to 671 molecules/10(7) molecules of 18S rRNA, whereas the amounts of CYP1A1 mRNA were <6 molecules/10 ng total RNA, indicating that CYP1A1 was not induced to a detectable level by environmentally exposed dioxins. The inducibility of CYP1B1 mRNA in leukocytes, defined as the ratio of CYP1B1 mRNA to the plasma concentration of dioxins, varied among the subjects. It was found that the subjects showed trimodal distribution according to inducibility: 39 (54.2%), 25 (34.7%), and 8 (11.1%) of 72 subjects were judged as poor, intermediate, and high responders to environmental dioxins, respectively. The amounts of CYP1B1 mRNA in leukocytes of the intermediate and high responders were highly correlated with the plasma concentrations of dioxins (P < 0.05 and <0.01). These results suggest that CYP1B1 with polymorphic inducibility by dioxins is involved in aromatic hydrocarbon hydroxylase activities in human lymphocytes.

  3. Cytochrome P450 1B1, a novel chemopreventive target for benzo[a]pyrene-initiated human esophageal cancer.

    PubMed

    Wen, Xia; Walle, Thomas

    2007-02-08

    Esophageal cancer is common worldwide, with poor prognosis. Smoking, including exposure to polyaromatic hydrocarbons like benzo[a]pyrene (BaP), is a major risk factor. In human esophageal HET-1A cells, we found that time-dependent BaP-DNA binding was associated with upregulation of CYP1B1, but not CYP1A1, mRNA and protein. The dietary flavonoid 5,7-dimethoxyflavone significantly inhibited BaP-DNA binding and down-regulated BaP-induced CYP1B1 mRNA and protein. 3',4'-Dimethoxyflavone was an even more potent inhibitor of CYP1B1 expression, while resveratrol had no effect. Thus, dietary methoxylated flavones inhibited BaP-induced CYP1B1 transcription in a cell-specific manner and hold promise as chemopreventive agents in esophageal carcinogenesis.

  4. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse

    SciTech Connect

    Siddens, Lisbeth K.; Bunde, Kristi L.; Harper, Tod A.; McQuistan, Tammie J.; Löhr, Christiane V.; Bramer, Lisa M.; Waters, Katrina M.; Tilton, Susan C.; Krueger, Sharon K.; and others

    2015-09-01

    FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.

  5. Leptin induces CYP1B1 expression in MCF-7 cells through ligand-independent activation of the ERα pathway

    SciTech Connect

    Khanal, Tilak; Kim, Hyung Gyun; Do, Minh Truong; Choi, Jae Ho; Won, Seong Su; Kang, Wonku; Chung, Young Chul; Jeong, Tae Cheon; Jeong, Hye Gwang

    2014-05-15

    Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118 and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK and Akt signalling pathways, which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells. - Highlights: • Leptin increased 4-hydroxyoestradiol in MCF-7 breast cancer cells. • Leptin activated ERK and Akt kinases related to ERα phosphorylation. • Leptin induces phosphorylation of ERα at serine residues 118 and 167. • Leptin induces ERE-luciferase activity.

  6. Expression Profile of CYP1A1 and CYP1B1 Enzymes in Colon and Bladder Tumors

    PubMed Central

    Androutsopoulos, Vasilis P.; Spyrou, Ioannis; Ploumidis, Achilles; Papalampros, Alexandros Eystathios; Kyriakakis, Michalis; Delakas, Demetrios; Spandidos, Demetrios A.; Tsatsakis, Aristidis M.

    2013-01-01

    Background The cytochrome P450 CYP1A1 and CYP1B1 enzymes are involved in carcinogenesis via activation of pro-carcinogenic compounds to carcinogenic metabolites. CYP1A1 and CYP1B1 have shown elevated levels in human tumors as determined by qRT-PCR and immunohistochemical studies. However studies that have examined CYP1 expression by enzyme activity assays are limited. Results In the current study the expression of CYP1A1 and CYP1B1 was investigated in a panel of human tumors of bladder and colorectal origin by qRT-PCR and enzyme activity assays. The results demonstrated that 35% (7/20) of bladder tumors and 35% (7/20) of colon tumors overexpressed active CYP1 enzymes. CYP1B1 mRNA was overexpressed in 65% and 60% of bladder and colon tumors respectively, whereas CYP1A1 was overexpressed in 65% and 80% of bladder and colon tumors. Mean mRNA levels of CYP1B1 and CYP1A1 along with mean CYP1 activity were higher in bladder and colon tumors compared to normal tissues (p<0.05). Statistical analysis revealed CYP1 expression levels to be independent of TNM status. Moreover, incubation of tumor microsomal protein in 4 bladder and 3 colon samples with a CYP1B1 specific antibody revealed a large reduction (72.5 ± 5.5 % for bladder and 71.8 ± 7.2% for colon) in catalytic activity, indicating that the activity was mainly attributed to CYP1B1 expression. Conclusions The study reveals active CYP1 overexpression in human tumors and uncovers the potential use of CYP1 enzymes and mainly CYP1B1 as targets for cancer therapy. PMID:24358191

  7. Mutation spectrum of CYP1B1 and MYOC genes in Korean patients with primary congenital glaucoma

    PubMed Central

    Kim, Hee-Jung; Suh, Wool; Park, Sung Chul; Kim, Chan Yun; Park, Ki Ho; Kook, Michael S.; Kim, Yong Yeon; Kim, Chang-Sik; Park, Chan Kee; Ki, Chang-Seok

    2011-01-01

    Purpose To elucidate the incidence of cytochrome P450 1B1 (CYP1B1) and myocillin (MYOC) mutations in Korean patients with primary congenital glaucoma (PCG). Methods Genomic DNA was collected from peripheral blood of 85 unrelated Korean patients who were diagnosed as having PCG by standard ophthalmological examinations and screened for mutations in the CYP1B1 and MYOC genes by using bi-directional sequencing. Results Among 85 patients with PCG, 22 patients (22/85; 25.9%) had either one (n=11) or two (n=11) mutant alleles of the CYP1B1 gene. Among 11 different CYP1B1 mutations identified, a frameshift mutation (c.970_971dupAT; p.T325SfsX104) was the most frequent mutant allele (6/33; 18.2%) while p.G329S and p.V419Gfs11X were novel. In the MYOC gene, two variants of unknown significance (p.L228S and p.E240G) were identified in two PCG patients (2/85; 2.4%), respectively. No patient had mutations in both genes. Conclusions Although CYP1B1 mutations are major causes of PCG in Korea, ~70% of PCG patients have neither CYP1B1 nor MYOC mutations suggesting a high degree of genetic heterogeneity. Furthermore, the fact that 11 out of 22 patients had only one mutant allele in the CYP1B1 gene necessitates further investigation for other genetic backgrounds underlying PCG. PMID:21850185

  8. Prediction of paclitaxel resistance in breast cancer: is CYP1B1*3 a new factor of influence?

    PubMed

    Gehrmann, Mathias; Schmidt, Markus; Brase, Jan C; Roos, Peter; Hengstler, Jan G

    2008-07-01

    This article focuses on the recent findings by Marsh and colleagues, and also discusses recent findings with regards to breast cancer. Taxanes are amongst the most active agents in the treatment of breast cancer. However, many tumors are intrinsically resistant. Therefore, it would be an enormous progress, if factors could be identified that reliably differentiate between taxane-sensitive and -resistant patients. Marsh and colleagues analyzed the CYP1B1*3 (Val432Leu) polymorphism in patients with high-risk stage III and IV breast cancer, who received dose-intense paclitaxel in combination with doxorubicin and cyclophosphamide. They report for the first time that patients with two leucine alleles in codon 432 of CYP1B1 experience a longer progression-free survival compared with patients with the Val/Leu or Val/Val genotypes. If confirmed in independent cohorts CYP1B1*3 may prove to be an important factor that helps to differentiate between paclitaxel-sensitive and resistant breast cancer patients. However, the mechanism behind the association between CYP1B1*3 and prognosis of paclitaxel-treated patients remains unclear. Several studies provide strong evidence that CYP1B1 does not influence tumor progression independently from paclitaxel chemotherapy, and that CYP1B1 itself does not alter paclitaxel resistance. In addition, CYP1B1 mRNA expression does not correlate with paclitaxel sensitivity of primary tumor cells. Although still speculative, a possible explanation is an association between CYP1B1*3 with still unknown factors that, on their part, influence paclitaxel sensitivity. In the future, studies with SNP chips and studies on the transcriptome, proteome and metabolome level should be performed in order to identify signatures differentiating between paclitaxel-sensitive and -resistant patients.

  9. Overexpression and enhanced specific activity of aldoketo reductases (AKR1B1 & AKR1B10) in human breast cancers.

    PubMed

    Reddy, K Ashok; Kumar, P Uday; Srinivasulu, M; Triveni, B; Sharada, K; Ismail, Ayesha; Reddy, G Bhanuprakash

    2017-02-01

    The incidence of breast cancer in India is on the rise and is rapidly becoming the primary cancer in Indian women. The aldoketo reductase (AKR) family has more than 190 proteins including aldose reductase (AKR1B1) and aldose reductase like protein (AKR1B10). Apart from liver cancer, the status of AKR1B1 and AKR1B10 with respect to their expression and activity has not been reported in other human cancers. We studied the specific activity and expression of AKR1B1 and AKR1B10 in breast non tumor and tumor tissues and in the blood. Fresh post-surgical breast cancer and non-cancer tissues and blood were collected from the subjects who were admitted for surgical therapy. Malignant, benign and pre-surgical chemotherapy samples were evaluated by histopathology scoring. Expression of AKR1B1 and AKR1B10 was carried out by immunoblotting and immunohistochemistry (IHC) while specific activity was determined spectrophotometrically. The specific activity of AKR1B1 was significantly higher in red blood cells (RBC) in all three grades of primary surgical and post-chemotherapy samples. Specific activity of both AKR1B1 and AKR1B10 increased in tumor samples compared to their corresponding non tumor samples (primary surgical and post-chemotherapy). Immunoblotting and IHC data also indicated overexpression of AKR1B1 in all grades of tumors compared to their corresponding non tumor samples. There was no change in the specific activity of AKR1B1 in benign samples compared to all grades of tumor and non-tumors.

  10. Influence of the functional polymorphisms in the organic anion transporting polypeptide 1B1 in the susceptibility to colorectal cancer.

    PubMed

    Ozhan, Gül; Kara, Mehtap; Sari, Fatih M; Yanar, Hakan T; Alpertunga, Buket

    2013-03-01

    Colorectal cancer is an important cause of death throughout the world, and its etiology involves the interaction of genetic and environmental factors. Transporter proteins are important in protecting organs from xenobiotics or toxins. Organic anion-transporting polypeptide 1B1 (OATP1B1) plays role in hepatic uptake and clearance of albumin-bound amphipathic organic compounds, including endogen substances, drugs, or xenobiotics. The SLCO1B1 gene expressing OATP1B1 is highly polymorphic. Up to now, SLCO1BI variants were the focus of several investigations on drug pharmacokinetics and cancer susceptibility. However, no information has been available on association between SLCO1B1 and colorectal cancer risk. Therefore, the study aims to investigate the relationship between colorectal cancer and the functional common variants of SLCO1B1 (388 A>G, -11187 G>A, 521 T>C) and to estimate the prevalence of these variants in the Turkish population. To that end, the distributions of the variants were determined in 100 patients with colorectal cancer and 150 healthy volunteers. SLCO1B1 521 T>C was statistically significantly associated with colorectal cancer risk (odds ratio [OR]=2.66; 95% confidence interval [CI]=1.31-5.41; p=0.0057). In haplotype-based analysis, SLCO1B1 haplotype G(388)-T(11187)-T(521) might be associated with the development of colorectal cancer (OR=4.26; 95% CI=1.62-11.16; p=0.002). We believe that the findings may be beneficial to the development of efficacious preventive strategies and therapies for colorectal cancer.

  11. APC2 and CYP1B1 methylation changes in the bone marrow of acute myeloid leukemia patients during chemotherapy

    PubMed Central

    Xia, Yongming; Hong, Qingxiao; Chen, Xiaoying; Ye, Huadan; Fang, Lili; Zhou, Annan; Gao, Yuting; Jiang, Danjie; Duan, Shiwei

    2016-01-01

    Aberrant promoter DNA methylation is a major mechanism of leukemogenesis in hematologic malignancies, including acute myeloid leukemia (AML). However, the association between promoter methylation with chemotherapeutic outcomes remains unknown. In the present study, bone marrow samples were collected prior to and following chemotherapy in 30 AML patients. Methylation-specific polymerase chain reaction technology was used to examine the promoter methylation status of adenomatous polyposis col 2 (APC2) and cytochrome P450 family 1 subfamily B polypeptide 1 (CYP1B1). The results revealed no change in the methylation status of the APC2 promoter in patients following various chemotherapy regimens. However, the methylation status of the CYP1B1 promoter changed in response to 6 different chemotherapy regimens. AML patients of the M3 subtype displayed an induction of the CYP1B1 promoter methylation levels more frequently (57.1%) than patients affected by the other subtypes (M1: 33.3%; M2: 12.5%; M4: 16.7%; M5: 0% and M6: 0%). In addition, a higher frequency of male patients (4/13) exhibited modulation of the CYP1B1 promoter methylation status compared with female patients (3/17). Furthermore, of five AML patients with a poor prognosis, two exhibited changes leading to CYP1B1 hypomethylation and two leading to CYP1B1 hypermethylation. By contrast, three other patients exhibited hypermethylation changes along with remission. This may be explained by the different chemotherapy regimens used to treat these patients or by other unknown factors. The present study revealed that CYP1B1 promoter methylation was induced during chemotherapy, whereas the APC2 promoter remained hemimethylated. Furthermore, the changes in CYP1B1 methylation were dependent on the AML subtypes and the gender of the patients. PMID:27882114

  12. APC2 and CYP1B1 methylation changes in the bone marrow of acute myeloid leukemia patients during chemotherapy.

    PubMed

    Xia, Yongming; Hong, Qingxiao; Chen, Xiaoying; Ye, Huadan; Fang, Lili; Zhou, Annan; Gao, Yuting; Jiang, Danjie; Duan, Shiwei

    2016-11-01

    Aberrant promoter DNA methylation is a major mechanism of leukemogenesis in hematologic malignancies, including acute myeloid leukemia (AML). However, the association between promoter methylation with chemotherapeutic outcomes remains unknown. In the present study, bone marrow samples were collected prior to and following chemotherapy in 30 AML patients. Methylation-specific polymerase chain reaction technology was used to examine the promoter methylation status of adenomatous polyposis col 2 (APC2) and cytochrome P450 family 1 subfamily B polypeptide 1 (CYP1B1). The results revealed no change in the methylation status of the APC2 promoter in patients following various chemotherapy regimens. However, the methylation status of the CYP1B1 promoter changed in response to 6 different chemotherapy regimens. AML patients of the M3 subtype displayed an induction of the CYP1B1 promoter methylation levels more frequently (57.1%) than patients affected by the other subtypes (M1: 33.3%; M2: 12.5%; M4: 16.7%; M5: 0% and M6: 0%). In addition, a higher frequency of male patients (4/13) exhibited modulation of the CYP1B1 promoter methylation status compared with female patients (3/17). Furthermore, of five AML patients with a poor prognosis, two exhibited changes leading to CYP1B1 hypomethylation and two leading to CYP1B1 hypermethylation. By contrast, three other patients exhibited hypermethylation changes along with remission. This may be explained by the different chemotherapy regimens used to treat these patients or by other unknown factors. The present study revealed that CYP1B1 promoter methylation was induced during chemotherapy, whereas the APC2 promoter remained hemimethylated. Furthermore, the changes in CYP1B1 methylation were dependent on the AML subtypes and the gender of the patients.

  13. Crystal structures of human sulfotransferases SULT1B1 and SULT1C1 complexed with the cofactor product adenosine-3'- 5'-diphosphate (PAP)

    SciTech Connect

    Dombrovski, Luidmila; Dong, Aiping; Bochkarev, Alexey; Plotnikov, Alexander N.

    2008-09-17

    Cytosolic sulfotransferases (SULTs), often referred as Phase II enzymes of chemical defense, are a superfamily of enzymes that catalyze the transfer of a sulfonate group from 3{prime}-phosphoadenosine 5{prime}-phosphosulfate (PAPS) to an acceptor group of substrates. This reaction modulates the activities of a large array of small endogenous and foreign chemicals including drugs, toxic compounds, steroid hormones, and neurotransmitters. In some cases, however, SULTs activate certain food and environmental compounds to mutagenenic and carcinogenic metabolites. Twelve human SULTs have been identified, which are partitioned into three families: SULT1, SULT2 and SULT4. The SULT1 family is further divided in four subfamilies, A, B, C, and E, and comprises eight members (1A1, 1A2, 1A3, 1B1, 1C1, 1C2, 1C3, and 1E1). Despite sequence and structural similarity among the SULTs, the family and subfamily members appear to have different biological function. SULT1 family shows substrate-binding specificity for simple phenols, estradiol, and thyroid hormones, as well as environmental xenobiotics and drugs. Human SULT1B1 is expressed in liver, colon, small intestine, and blood leukocytes, and shows substrate-binding specificity to thyroid hormones and benzylic alcohols. Human SULT1C1 is expressed in the adult stomach, kidney, and thyroid, as well as in fetal kidney and liver. SULT1C1 catalyzes the sulfonation of p-nitrophenol and N-hydroxy-2-acetylaminofluorene in vitro. However, the in vivo function of the enzyme remains unknown. We intend to solve the structures for all of the SULTs for which structural information is not yet available, and compare the structural and functional features of the entire SULT superfamily. Here we report the structures of two members of SULT1 family, SULT1B1 and SULT1C1, both in complex with the product of the PAPS cofactor, adenosine-3{prime}-5{prime}-diphosphate (PAP).

  14. Dopamine D2-Receptor Antagonists Down-Regulate CYP1A1/2 and CYP1B1 in the Rat Liver

    PubMed Central

    Harkitis, P.; Lang, M. A.; Marselos, M.; Fotopoulos, A.; Albucharali, G.; Konstandi, M.

    2015-01-01

    Dopaminergic systems regulate the release of several hormones including growth hormone (GH), thyroid hormones, insulin, glucocorticoids and prolactin (PRL) that play significant roles in the regulation of various Cytochrome P450 (CYP) enzymes. The present study investigated the role of dopamine D2-receptor-linked pathways in the regulation of CYP1A1, CYP1A2 and CYP1B1 that belong to a battery of genes controlled by the Aryl Hydrocarbon Receptor (AhR) and play a crucial role in the metabolism and toxicity of numerous environmental toxicants. Inhibition of dopamine D2-receptors with sulpiride (SULP) significantly repressed the constitutive and benzo[a]pyrene (B[a]P)-induced CYP1A1, CYP1A2 and CYP1B expression in the rat liver. The expression of AhR, heat shock protein 90 (HSP90) and AhR nuclear translocator (ARNT) was suppressed by SULP in B[a]P-treated livers, whereas the AhRR expression was increased by the drug suggesting that the SULP-mediated repression of the CYP1 inducibility is due to inactivation of the AhR regulatory system. At signal transduction level, the D2-mediated down-regulation of constitutive CYP1A1/2 and CYP1B1 expression appears to be mediated by activation of the insulin/PI3K/AKT pathway. PRL-linked pathways exerting a negative control on various CYPs, and inactivation of the glucocorticoid-linked pathways that positively control the AhR-regulated CYP1 genes, may also participate in the SULP-mediated repression of both, the constitutive and induced CYP1 expression. The present findings indicate that drugs acting as D2-dopamine receptor antagonists can modify several hormone systems that regulate the expression of CYP1A1, CYP1A2 and CYP1B1, and may affect the toxicity and carcinogenicity outcome of numerous toxicants and pre-carcinogenic substances. Therefore, these drugs could be considered as a part of the strategy to reduce the risk of exposure to environmental pollutants and pre-carcinogens. PMID:26466350

  15. Role of CYP1B1, MYOC, OPTN and OPTC genes in adult-onset primary open-angle glaucoma: predominance of CYP1B1 mutations in Indian patients

    PubMed Central

    Basavaraj, Manjunath G.; Gupta, Santosh K.; Qamar, Imteyaz; Ali, Abdullah Mahmood; Bajaj, Vineeta; Ramesh, T.K.; Prakash, D. Ravi; Shetty, Jyoti S.; Dorairaj, Syril K.

    2007-01-01

    Purpose Mutations in the CYP1B1, MYOC, OPTN, and WDR36 genes result in glaucoma. Given its expression in the optic nerve, it is likely a mutation in the OPTC gene is also involved in initiating glaucoma. This study was designed to evaluate the involvement of the CYP1B1, MYOC, OPTN, and OPTC genes in the etiology of adult-onset primary open-angle glaucoma (POAG) found in 251 Indian patients. Methods Blood samples were obtained from individuals for DNA isolation. A combination of polymerase chain reaction-single strand conformation polymorphism, allele-specific PCR, and DNA sequencing techniques were used to detect mutations in four genes. Four microsatellite markers from the CYP1B1 candidate region and three intragenic CYP1B1 single nucleotide polymorphisms (SNPs) were used to determine the origin of the most common CYP1B1 mutations. Results Three previously known mutations (Pro193Leu, Glu229Lys, and Arg368His) and one novel (Met292Lys) mutation were found in the CYP1B1 gene. Frequencies of the most common mutations, Glu229Lys and Arg368His, in patients were 5.12% and 3.98%, respectively. The Glu229Lys and Arg368His mutations were also found in normal controls at frequencies of 5% and 2%, respectively, suggesting that these mutations might be polymorphic variants in our population. The absence of allele sharing for D2S177, D2S1346, D2S2974, and D2S2331 markers and three intragenic CYP1B1 SNPs in patients suggested multiple origins for the Glu229Lys and Arg368His variants. Two of 251 (0.8%) patients had the Gln48His mutation in MYOC. There was no difference in the frequency of a MYOC -83G>A promoter polymorphism between patients and controls. A novel OPTN mutation, Thr202Arg, was detected in one of 251 (0.4%) patients. The OPTN variant Met98Lys was detected in similar frequencies in patients and controls. No mutation was detected in OPTC. Taken together, 3.59% (9/251) of our POAG patients had mutations in the CYP1B1, MYOC, and OPTN genes. Conclusions This is the

  16. Dimeric human sulfotransferase 1B1 displays cofactor-dependent subunit communication

    PubMed Central

    Tibbs, Zachary E; Falany, Charles N

    2015-01-01

    The cytosolic sulfotransferases (SULTs) are dimeric enzymes that catalyze the transformation of hydrophobic drugs and hormones into hydrophilic sulfate esters thereby providing the body with an important pathway for regulating small molecule activity and excretion. While SULT dimerization is highly conserved, the necessity for the interaction has not been established. To perform its function, a SULT must efficiently bind the universal sulfate donor, 3′-phosphoadenosine-5′-phosphosulfate (PAPS), and release the byproduct, 3′, 5′-diphosphoadenosine (PAP), following catalysis. We hypothesize this efficient binding and release of PAPS/PAP may be connected to SULT dimerization. To allow for the visualization of dynamic protein interactions critical for addressing this hypothesis and to generate kinetically testable hypotheses, molecular dynamic simulations (MDS) of hSULT1B1 were performed with PAPS and PAP bound to each dimer subunit in various combinations. The results suggest the dimer subunits may possess the capability of communicating with one another in a manner dependent on the presence of the cofactor. PAP or PAPS binding to a single side of the dimer results in decreased backbone flexibility of both the bound and unbound subunits, implying the dimer subunits may not act independently. Further, binding of PAP to one subunit of the dimer and PAPS to the other caused increased flexibility in the subunit bound to the inactive cofactor (PAP). These results suggest SULT dimerization may be important in maintaining cofactor binding/release properties of SULTs and provide hypothetical explanations for SULT half-site reactivity and substrate inhibition, which can be analyzed in vitro. PMID:26236487

  17. Estrogen and Cytochrome P450 1B1 Contribute to Both Early- and Late-Stage Head and Neck Carcinogenesis

    PubMed Central

    Shatalova, Ekaterina G.; Klein-Szanto, Andres J.P.; Devarajan, Karthik; Cukierman, Edna; Clapper, Margie L.

    2010-01-01

    Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most common type of cancer in the U.S. The goal of this study was to evaluate the contribution of estrogens to the development of HNSCCs. Various cell lines derived from early- and late-stage head and neck lesions were used to: characterize the expression of estrogen synthesis and metabolism genes, including cytochrome P450 (CYP)1B1, examine the effect of estrogen on gene expression and evaluate the role of CYP1B1 and/or estrogen in cell motility, proliferation and apoptosis. Estrogen metabolism genes (CYP1B1, CYP1A1, catechol-o-methyltransferase, UDP-glucuronosyltransferase 1A1, and glutathione-S-transferase P1) and estrogen receptor (ER)β were expressed in cell lines derived from both premalignant (MSK-Leuk1) and malignant (HNSCC) lesions. Exposure to estrogen induced CYP1B1 2.3 to 3.6 fold relative to vehicle-treated controls (P=0.0004) in MSK-Leuk1 cells but not in HNSCC cells. CYP1B1 knockdown by shRNA reduced the migration and proliferation of MSK-Leuk1 cells by 57% and 45%, respectively. Exposure of MSK-Leuk1 cells to estrogen inhibited apoptosis by 26%, while supplementation with the antiestrogen fulvestrant restored estrogen-dependent apoptosis. Representation of the estrogen pathway in human head and neck tissues from 128 patients was examined using tissue microarrays. The majority of the samples exhibited immunohistochemical staining for ERβ (91.9%), CYP1B1 (99.4%) and 17β-estradiol (88.4%). CYP1B1 and ERβ were elevated in HNSCCs relative to normal epithelium (P=0.024 and 0.008, respectively). These data provide novel insight into the mechanisms underlying head and neck carcinogenesis and facilitate the identification new targets for chemopreventive intervention. PMID:21205741

  18. Genetic polymorphisms in catalase and CYP1B1 determine DNA adduct formation by benzo(a)pyrene ex vivo.

    PubMed

    Schults, Marten A; Chiu, Roland K; Nagle, Peter W; Wilms, Lonneke C; Kleinjans, Jos C; van Schooten, Frederik J; Godschalk, Roger W

    2013-03-01

    Genetic polymorphisms can partially explain the large inter-individual variation in DNA adduct levels following exposure to polycyclic aromatic hydrocarbons. Effects of genetic polymorphisms on DNA adduct formation are difficult to assess in human studies because exposure misclassification attenuates underlying relationships. Conversely, ex vivo studies offer the advantage of controlled exposure settings, allowing the possibility to better elucidate genotype-phenotype relationships and gene-gene interactions. Therefore, we exposed lymphocytes of 168 non-smoking volunteers ex vivo to the environmental pollutant benzo(a)pyrene (BaP) and BaP-related DNA adducts were quantified. Thirty-four genetic polymorphisms were assessed in genes involved in carcinogen metabolism, oxidative stress and DNA repair. Polymorphisms in catalase (CAT, rs1001179) and cytochrome P450 1B1 (CYP1B1, rs1800440) were significantly associated with DNA adduct levels, especially when combined. Moreover, reverse transcription-polymerase chain reaction (RT-PCR) analysis in a subset of 30 subjects revealed that expression of catalase correlated strongly with expression of CYP1B1 (R = 0.92, P < 0.001). To further investigate the mechanism by which catalase influences CYP1B1 and how they simultaneously affect BaP-related DNA adduct levels, catalase expression was transiently knocked down in the human lung epithelial cell line A549. Although catalase knockdown did not immediately change CYP1B1 gene expression, recovery of catalase expression 8 h after the knockdown coincided with a 2.2-fold increased expression of CYP1B1 (P < 0.05). We conclude that the genetic polymorphism in the promoter region of CAT may determine the amount and activity of catalase, which may subsequently regulate the expression of CYP1B1. As a result, both genetic polymorphisms modulate DNA adduct levels in lymphocytes by BaP ex vivo.

  19. Selectivity and potency of microcystin congeners against OATP1B1 and OATP1B3 expressing cancer cells.

    PubMed

    Niedermeyer, Timo H J; Daily, Abigail; Swiatecka-Hagenbruch, Monika; Moscow, Jeffrey A

    2014-01-01

    Microcystins are potent phosphatase inhibitors and cellular toxins. They require active transport by OATP1B1 and OATP1B3 transporters for uptake into human cells, and the high expression of these transporters in the liver accounts for their selective hepatic toxicity. Several human tumors have been shown to have high levels of expression of OATP1B3 but not OATP1B1, the main transporter in liver cells. We hypothesized that microcystin variants could be isolated that are transported preferentially by OATP1B3 relative to OATP1B1 to advance as anticancer agents with clinically tolerable hepatic toxicity. Microcystin variants have been isolated and tested for cytotoxicity in cancer cells stably transfected with OATP1B1 and OATP1B3 transporters. Microcystin variants with cytotoxic OATP1B1/OATP1B3 IC50 ratios that ranged between 0.2 and 32 were found, representing a 150-fold range in transporter selectivity. As microcystin structure has a significant impact on transporter selectivity, it is potentially possible to develop analogs with even more pronounced OATP1B3 selectivity and thus enable their development as anticancer drugs.

  20. Curated human hyperbilirubinemia data and the respective OATP1B1 and 1B3 inhibition predictions.

    PubMed

    Kotsampasakou, Eleni; Escher, Sylvia E; Ecker, Gerhard F

    2017-04-01

    Hyperbilirubinemia is a pathological condition, very often indicative of underlying liver condition that is characterized by excessive accumulation of conjugated or unconjugated bilirubin in sinusoidal blood. In literature there are several indications associating the inhibition of the basolateral hepatic transporters Organic anion transporting polypeptide 1B1 and 1B3 (OATP1B1 and 1B3) with hyperbilirubinemia. In this article, we present a curated human hyperbilirubinemia dataset and the respective OATP1B1 and 1B3 inhibition predictions obtained from an effort to generate a classification model for hyperbilirubinemia. These data originate from the research article "Linking organic anion transporting polypeptide 1b1 and 1b3 (oatp1b1 and oatp1b3) interaction profiles to hepatotoxicity- the hyperbilirubinemia use case" (E. Kotsampasakou, S.E. Escher, G.F. Ecker, 2017) [1]. We further provide the full list of descriptors used for generating the hyperbilirubinemia classification models as well as the calculated descriptors for each compound of the dataset that was used to build the classification model.

  1. Differential effect of the rs4149056 variant in SLCO1B1 on myopathy associated with simvastatin and atorvastatin.

    PubMed

    Brunham, L R; Lansberg, P J; Zhang, L; Miao, F; Carter, C; Hovingh, G K; Visscher, H; Jukema, J W; Stalenhoef, A F; Ross, C J D; Carleton, B C; Kastelein, J J P; Hayden, M R

    2012-06-01

    Statins reduce cardiovascular morbidity and mortality in appropriately selected patients. However, statin-associated myopathy is a significant risk associated with these agents. Recently, variation in the SLCO1B1 gene was reported to predict simvastatin-associated myopathy. The aim of this study was to replicate association of the rs4149056 variant in SLCO1B1 with severe statin-associated myopathy in a cohort of patients using a variety of statin medications and to investigate the association with specific statin types. We identified 25 cases of severe statin-associated myopathy and 84 controls matched for age, gender, statin type and dose. The rs4149056 variant in SLCO1B1 was not significantly associated with myopathy in this group as a whole. However, when subjects were stratified by statin type, the SLCO1B1 rs4149056 genotype was significantly associated with myopathy in patients who received simvastatin, but not in patients who received atorvastatin. Our findings provide further support for a role for SLCO1B1 genotype in simvastatin-associated myopathy, and suggest that this association may be stronger for simvastatin compared with atorvastatin.

  2. N-Glycosylation of Serum IgG and Total Glycoproteins in MAN1B1 Deficiency.

    PubMed

    Saldova, Radka; Stöckmann, Henning; O'Flaherty, Roisin; Lefeber, Dirk J; Jaeken, Jaak; Rudd, Pauline M

    2015-10-02

    MAN1B1-CDG has recently been characterized as a type II congenital disorder of glycosylation (CDG), disrupting not only protein N-glycosylation but also general Golgi morphology. Using our high-throughput, quantitative ultra-performance liquid chromatography assay, we achieved a detailed characterization of the glycosylation changes in both total serum glycoproteins and isolated serum IgG from ten previously reported MAN1B1-CDG patients. We have identified and quantified novel hybrid high-mannosylated MAN1B1-CDG-specific IgG glycans and found an increase of sialyl Lewis x (sLex) glycans on serum proteins of all patients. This increase in sLex has not been previously reported in any CDG. These findings may provide insight into the pathophysiology of this CDG.

  3. CYP1B1 C4326G polymorphism and susceptibility to cervical cancer in Chinese Han women.

    PubMed

    Li, Ya; Tan, Shi-Qiao; Ma, Qian-Hong; Li, Lei; Huang, Zhong-Ying; Wang, Yan; Li, Shang-Wei

    2013-12-01

    Cytochrome P450 1B1 (CYP1B1) is a key P450 enzyme, which could catalyze the formation of 4-hydroxy estrogen metabolites and play a role in estrogen-dependent cancers. We hypothesized that genetic variant in CYP1B1 may modify individual susceptibility to cervical cancer. The aim of this study was to evaluate the association between CYP1B1 C4326G polymorphism and cervical cancer risk in Chinese women. We extracted the peripheral blood samples in 250 patients with cervical cancer and 250 female controls. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry method and direct DNA sequencing were performed to detect the polymorphism. The frequencies of CC, CG, and GG genotypes of CYP1B1 C4326G in cases and controls were 66.0, 26.8, 7.2% and 75.2, 21.6, and 3.2%, respectively, and there was a significant difference between the two groups (P = 0.034). Compared with the wild-type CC genotype, the variant GG genotype was associated with a significantly increased risk of cervical cancer (adjusted OR = 2.30; 95% CI = 1.02, 5.50). Moreover, stratification analysis by age, smoking, drinking, human papillomaviruses (HPV) 16 or 18 carrier status, and family history of cervical cancer, we found that the variant genotypes containing the G allele were associated with a significantly increased risk of cervical cancer among HPV 16 or 18-positive individuals (adjusted OR = 2.85; 95% CI = 1.45, 5.62) and among women younger than 45 years old (adjusted OR = 1.87; 95% CI = 1.03, 3.37). These results suggest that CYP1B1 C4326G polymorphism may increase risk of cervical cancer in Chinese women, especially among young individuals with high-risk HPV infection.

  4. Association of CYP1B1 L432V polymorphism with urinary cancer susceptibility: a meta-analysis

    PubMed Central

    2014-01-01

    Abstract Background The Cytochrome P450 1B1 (CYP1B1) is a key P450 enzyme involved in the metabolism of exogenous and endogenous substrates. Previous studies have reported the existence of CYP1B1 L432V missense polymorphism in prostate, bladder and renal cancers. However, the effects of this polymorphism on the risk of these cancers remain conflicting. Therefore, we performed a meta-analysis to assess the association between L432V polymorphism and the susceptibility of urinary cancers. Methods We searched the PubMed database without limits on language for studies exploring the relationship of CYP1B1 L432V polymorphism and urinary cancers. Article search was supplemented by screening the references of retrieved studies manually. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate the strength of these associations. Simultaneously, publication bias was estimated by funnel plot and Begg’s test with Stata 11 software. Results We observed a significant association between CYP1B1 L432V polymorphism and urinary cancers. The overall OR (95% CI) of CC versus CG was 0.937 (0.881-0.996), the overall OR (95% CI) of CC versus CG + GG was 0.942 (0.890-0.997). Furthermore, we identified reduced risk for CC versus other phenotypes in both prostate and overall urinary cancers, when studies were limited to Caucasian or Asian patients. Conclusions This meta-analysis suggests that the CYP1B1 L432V polymorphism is associated with urinary cancer risk. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3108829721231527 PMID:24913727

  5. CYP1B1 Enhances Cell Proliferation and Metastasis through Induction of EMT and Activation of Wnt/β-Catenin Signaling via Sp1 Upregulation

    PubMed Central

    Kwon, Yeo-Jung; Baek, Hyoung-Seok; Ye, Dong-Jin; Shin, Sangyun; Kim, Donghak; Chun, Young-Jin

    2016-01-01

    Cytochrome P450 1B1 (CYP1B1) is a major E2 hydroxylase involved in the metabolism of potential carcinogens. CYP1B1 expression has been reported to be higher in tumors compared to normal tissues, especially in hormone-related cancers including breast, ovary, and prostate tumors. To explore the role of CYP1B1 in cancer progression, we investigated the action of CYP1B1 in cells with increased CYP1B1 via the inducer 7,12-dimethylbenz[α]anthracene (DMBA) or an overexpression vector, in addition to decreased CYP1B1 via the inhibitor tetramethoxystilbene (TMS) or siRNA knockdown. We observed that CYP1B1 promoted cell proliferation, migration, and invasion in MCF-7 and MCF-10A cells. To understand its molecular mechanism, we measured key oncogenic proteins including β-catenin, c-Myc, ZEB2, and matrix metalloproteinases following CYP1B1 modulation. CYP1B1 induced epithelial-mesenchymal transition (EMT) and activated Wnt/β-catenin signaling via upregulation of CTNNB1, ZEB2, SNAI1, and TWIST1. Sp1, a transcription factor involved in cell growth and metastasis, was positively regulated by CYP1B1, and suppression of Sp1 expression by siRNA or DNA binding activity using mithramycin A blocked oncogenic transformation by CYP1B1. Therefore, we suggest that Sp1 acts as a key mediator for CYP1B1 action. Treatment with 4-hydroxyestradiol (4-OHE2), a major metabolite generated by CYP1B1, showed similar effects as CYP1B1 overexpression, indicating that CYP1B1 activity mediated various oncogenic events in cells. In conclusion, our data suggests that CYP1B1 promotes cell proliferation and metastasis by inducing EMT and Wnt/β-catenin signaling via Sp1 induction. PMID:26981862

  6. CYP1B1 Enhances Cell Proliferation and Metastasis through Induction of EMT and Activation of Wnt/β-Catenin Signaling via Sp1 Upregulation.

    PubMed

    Kwon, Yeo-Jung; Baek, Hyoung-Seok; Ye, Dong-Jin; Shin, Sangyun; Kim, Donghak; Chun, Young-Jin

    2016-01-01

    Cytochrome P450 1B1 (CYP1B1) is a major E2 hydroxylase involved in the metabolism of potential carcinogens. CYP1B1 expression has been reported to be higher in tumors compared to normal tissues, especially in hormone-related cancers including breast, ovary, and prostate tumors. To explore the role of CYP1B1 in cancer progression, we investigated the action of CYP1B1 in cells with increased CYP1B1 via the inducer 7,12-dimethylbenz[α]anthracene (DMBA) or an overexpression vector, in addition to decreased CYP1B1 via the inhibitor tetramethoxystilbene (TMS) or siRNA knockdown. We observed that CYP1B1 promoted cell proliferation, migration, and invasion in MCF-7 and MCF-10A cells. To understand its molecular mechanism, we measured key oncogenic proteins including β-catenin, c-Myc, ZEB2, and matrix metalloproteinases following CYP1B1 modulation. CYP1B1 induced epithelial-mesenchymal transition (EMT) and activated Wnt/β-catenin signaling via upregulation of CTNNB1, ZEB2, SNAI1, and TWIST1. Sp1, a transcription factor involved in cell growth and metastasis, was positively regulated by CYP1B1, and suppression of Sp1 expression by siRNA or DNA binding activity using mithramycin A blocked oncogenic transformation by CYP1B1. Therefore, we suggest that Sp1 acts as a key mediator for CYP1B1 action. Treatment with 4-hydroxyestradiol (4-OHE2), a major metabolite generated by CYP1B1, showed similar effects as CYP1B1 overexpression, indicating that CYP1B1 activity mediated various oncogenic events in cells. In conclusion, our data suggests that CYP1B1 promotes cell proliferation and metastasis by inducing EMT and Wnt/β-catenin signaling via Sp1 induction.

  7. Effect of SLCO1B1 Polymorphisms on Rifabutin Pharmacokinetics in African HIV-Infected Patients with Tuberculosis.

    PubMed

    Hennig, Stefanie; Naiker, Suhashni; Reddy, Tarylee; Egan, Deirdre; Kellerman, Tracy; Wiesner, Lubbe; Owen, Andrew; McIlleron, Helen; Pym, Alexander

    2015-10-19

    Rifabutin, used to treat HIV-infected tuberculosis, shows highly variable drug exposure, complicating dosing. Effects of SLCO1B1 polymorphisms on rifabutin pharmacokinetics were investigated in 35 African HIV-infected tuberculosis patients after multiple doses. Nonlinear mixed-effects modeling found that influential covariates for the pharmacokinetics were weight, sex, and a 30% increased bioavailability among heterozygous carriers of SLCO1B1 rs1104581 (previously associated with low rifampin concentrations). Larger studies are needed to understand the complex interactions of host genetics in HIV-infected tuberculosis patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT00640887.).

  8. Effect of SLCO1B1 Polymorphisms on Rifabutin Pharmacokinetics in African HIV-Infected Patients with Tuberculosis

    PubMed Central

    Naiker, Suhashni; Reddy, Tarylee; Egan, Deirdre; Kellerman, Tracy; Wiesner, Lubbe; Owen, Andrew; McIlleron, Helen; Pym, Alexander

    2015-01-01

    Rifabutin, used to treat HIV-infected tuberculosis, shows highly variable drug exposure, complicating dosing. Effects of SLCO1B1 polymorphisms on rifabutin pharmacokinetics were investigated in 35 African HIV-infected tuberculosis patients after multiple doses. Nonlinear mixed-effects modeling found that influential covariates for the pharmacokinetics were weight, sex, and a 30% increased bioavailability among heterozygous carriers of SLCO1B1 rs1104581 (previously associated with low rifampin concentrations). Larger studies are needed to understand the complex interactions of host genetics in HIV-infected tuberculosis patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT00640887.) PMID:26482301

  9. Association of CYP1B1 gene polymorphisms with susceptibility to endometrial cancer: a meta-analysis.

    PubMed

    Wang, Fang; Zou, Yan-Feng; Sun, Guo-Ping; Su, Hong; Huang, Fen

    2011-03-01

    The objective of this meta-analysis was to quantitatively summarize the association of CYP1B1 gene polymorphisms and endometrial cancer risk. Data were collected from the following electronic databases: PubMed,Elsevier Science Direct, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure and Wanfang, with the last report up to June 2010. Meta-analysis was conducted in a fixed/random effect model. Out of the 715 papers retrieved 12 studies (3605 cases and 5692 controls) on the association of CYP1B1 gene polymorphisms with endometrial cancer risk in different ethnic groups were identified. Meta-analysis was performed for CYP1B1 gene polymorphisms: R48G (C/G, five studies), L432V (C/G, 12 studies), N453S (A/G, four studies), and A119S (G/T, five studies). We did not detect any association of CYP1B1 gene A119S polymorphism with endometrial cancer. An association of CYP1B1 gene R48G polymorphism with endometrial cancer was found [GG vs. GC+CC: odds ratio (OR)=0.55, 95% confidence interval (CI): 0.42-0.73, P<0.0001; GG vs. CC: OR=0.46, 95% CI: 0.23-0.91, P=0.03]. We found that CYP1B1 gene L432V polymorphism was associated with a significantly increased risk of endometrial cancer (G vs. C: OR=1.23, 95% CI: 1.06-1.43, P=0.007; GC+GG vs. CC:OR=1.24, 95% CI: 1.08-1.43, P=0.003; GC vs. CC: OR=1.16, 95% CI: 1.04-1.29, P=0.009). Moreover, we detected the association of CYP1B1 gene N453S polymorphism with endometrial cancer (G vs. A: OR=0.82,95% CI: 0.72-0.94, P=0.005; GA vs. AA: OR=0.81, 95% CI: 0.69-0.95, P=0.01). In conclusion, this meta-analysis provides strong evidence that CYP1B1 gene R48G, L432V, and N453S polymorphisms are associated with endometrial cancer risk, but not A119S.

  10. Effects of hydroxyl group numbers on the B-ring of 5,7-dihydroxyflavones on the differential inhibition of human CYP 1A and CYP1B1 enzymes.

    PubMed

    Kim, Hyun-Jung; Lee, Sang Bum; Park, Song-Kyu; Kim, Hwan Mook; Park, Young In; Dong, Mi-Sook

    2005-10-01

    Flavonoids are polyphenols composed of two aromatic rings (A, B) and a heterocyclic ring (C). In order to determine the effects of the number of hydroxyl groups in the B-ring of the flavonoids on human cytochrome P450 (CYP) 1 family enzymes, we evaluated the inhibition of CYP1A-dependent 7-ethoxyresorufin omicron-deethylation activity by chrysin, apigenin and luteolin, using bacterial membranes that co-express human CYP1A1, CYP1A2, or CYP1B1 with human NADPH-cytochrome P450 reductase. Chrysin, which possesses no hydroxyl groups in its B-ring, exhibited the most pronounced inhibitory effects on CYP1A2-dependent EROD activity, followed by apigenin and luteolin. On the contrary, CYP1A1-mediated EROD activity was most potently inhibited by luteolin, which is characterized by two hydroxyl groups in its B-ring, followed by apigenin and chrysin. However, all of the 5,7-dihydroxyflavones were determined to similarly inhibit CYP1B1 activity. Chrysin, apigenin, and luteolin exhibited a mixed-type mode of inhibition with regard to CYP1A2, CYP1B1, and CYP1A1, with apparent Ki values of 2.4, 0.5, and 2.0 microM, respectively. These findings suggested that the number of hydroxyl groups in the B-ring of 5,7-dihydroxyflavone might have some influence on the degree to which CYP1A enzymes were inhibited, but not on the degree to which CYP1B1 enzymes were inhibited.

  11. Polycyclic aromatic hydrocarbon-induced CYP1B1 activity is suppressed by perillyl alcohol in MCF-7 cells

    SciTech Connect

    Chan, Nelson L.S.; Wang Huan; Wang Yun; Leung, H.Y.; Leung, Lai K. . E-mail: laikleung@yahoo.com

    2006-06-01

    Perillyl alcohol (POH) is a dietary monoterpene with potential applications in chemoprevention and chemotherapy. Although clinical trials are under way, POH's physiological and pharmacological properties are still unclear. In the present study, the effect of POH on polycyclic aromatic hydrocarbon (PAH)-induced genotoxicity, and the related expression were examined in MCF-7 cells. Exposure to environmental toxicant increases the risk of cancer. Many of these compounds are pro-carcinogens and are biotransformed into their ultimate genotoxic structures by xenobiotic metabolizing enzymes. CYP1A1 and 1B1 are enzymes that catalyze the biotransformation of dimethylbenz[a]anthracene (DMBA). Our data revealed that 0.5 {mu}M of POH was effective in blocking DMBA-DNA binding. Ethoxyresorufin-O-deethylase (EROD) assay indicated that the administration of POH inhibited the DMBA-induced enzyme activity in MCF-7 cells. Enzyme kinetic analysis revealed that POH inhibited CYP1B1 but not CYP1A1 activity. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay also demonstrated that the monoterpene reduced CYP1B1 mRNA abundance induced by DMBA. The present study illustrated that POH might inhibit and downregulate CYP1B1, which could protect against PAH-induced carcinogenesis.

  12. Leu/Val SNP polymorphism of CYP1B1 and risk of uterine leiomyoma in a Black population.

    PubMed

    Bideau, Virgil S; Alleyne, Angela T

    2016-03-01

    Uterine leiomyoma (UL) is the most commonly occurring benign tumor that affects women of reproductive ages. Studies strongly suggest that ULs are hormonally dependent and that genes acting in estrogen metabolism might be involved in their development. The focus of this case-control study was to determine whether the Leucine432Valine single-nucleotide polymorphism (SNP) in the gene encoding cytochrome P450 1B1 (CYP1B1) was associated with an increased risk of UL in Black Barbadian women. The investigation comprised 37 women clinically diagnosed with UL and 52 controls. The CYP1B1 Leu432Val polymorphism (Leu/Val) was analyzed using the polymerase chain reaction-restriction fragment length polymorphism method. The homozygous Valine432 variant (Val/Val) was predominant in both cases and controls for this population (89 and 83 %, respectively). The odds ratio for risk of developing the disease was 1.33, but this was not statistically significant. We discuss a possible protective function for CYP1B1 based on the high prevalence of this mutant SNP and its lack of association with UL.

  13. Polymorphisms in CYP1B1, GSTM1, GSTT1 and GSTP1, and susceptibility to breast cancer.

    PubMed

    Van Emburgh, Beth O; Hu, Jennifer J; Levine, Edward A; Mosley, Libyadda J; Perrier, Nancy D; Freimanis, Rita I; Allen, Glenn O; Rubin, Peter; Sherrill, Gary B; Shaw, Cindy S; Carey, Lisa A; Sawyer, Lynda R; Miller, Mark Steven

    2008-05-01

    Polymorphisms in the cytochrome P450 1B1 (CYP1B1) and glutathione S-transferase (GST) drug metabolic enzymes, which are responsible for metabolic activation/detoxification of estrogen and environmental carcinogens, were analyzed for their association with breast cancer risk in 541 cases and 635 controls from a North Carolina population. Each polymorphism, altering the catalytic function of their respective enzymes, was analyzed in Caucasian and African-American women. As reported in previous studies, individual polymorphisms did not significantly impact breast cancer risk in either Caucasian or African-American women. However, African-American women exhibited a trend towards a protective effect when they had at least one CYP1B1 119S allele (OR=0.53; 95% CI=0.20-1.40) and increased risk for those women harboring at least one CYP1B1 432V allele (OR=5.52; 95% CI=0.50-61.37). Stratified analyses demonstrated significant interactions in younger (age < or =60) Caucasian women with the CYP1B1 119SS genotype (OR=3.09; 95% CI=1.22-7.84) and younger African-American women with the GSTT1 null genotype (OR=4.07; 95% CI=1.12-14.80). A notable trend was also found in Caucasian women with a history of smoking and at least one valine allele at GSTP1 114 (OR=2.12; 95% CI=1.02-4.41). In Caucasian women, the combined GSTP1 105IV/VV and CYP1B1 119AA genotypes resulted in a near 2-fold increase in risk (OR=1.96; 95% CI=1.04-3.72) and the three way combination of GSTP1 105IV/VV, CYP1B1 119AS/SS and GSTT1 null genotypes resulted in an almost 4-fold increase in risk (OR=3.97; 95% CI=1.27-12.40). These results suggest the importance of estrogen/carcinogen metabolic enzymes in the etiology of breast cancer, especially in women before the age of 60, as well as preventative measures such as smoking cessation.

  14. Polymorphisms in CYP1B1, GSTM1, GSTT1 and GSTP1, and susceptibility to breast cancer

    PubMed Central

    Van Emburgh, Beth O.; Hu, Jennifer J.; Levine, Edward A.; Mosley, Libyadda J.; Perrier, Nancy D.; Freimanis, Rita I.; Allen, Glenn O.; Rubin, Peter; Sherrill, Gary B.; Shaw, Cindy S.; Carey, Lisa A.; Sawyer, Lynda R.; Miller, Mark Steven

    2013-01-01

    Polymorphisms in the cytochrome P450 1B1 (CYP1B1) and glutathione S-transferase (GST) drug metabolic enzymes, which are responsible for metabolic activation/detoxification of estrogen and environmental carcinogens, were analyzed for their association with breast cancer risk in 541 cases and 635 controls from a North Carolina population. Each polymorphism, altering the catalytic function of their respective enzymes, was analyzed in Caucasian and African-American women. As reported in previous studies, individual polymorphisms did not significantly impact breast cancer risk in either Caucasian or African-American women. However, African-American women exhibited a trend towards a protective effect when they had at least one CYP1B1 119S allele (OR=0.53; 95% CI=0.20–1.40) and increased risk for those women harboring at least one CYP1B1 432V allele (OR=5.52; 95% CI=0.50–61.37). Stratified analyses demonstrated significant interactions in younger (age ≤60) Caucasian women with the CYP1B1 119SS genotype (OR=3.09; 95% CI=1.22–7.84) and younger African-American women with the GSTT1 null genotype (OR=4.07; 95% CI=1.12–14.80). A notable trend was also found in Caucasian women with a history of smoking and at least one valine allele at GSTP1 114 (OR=2.12; 95% CI=1.02–4.41). In Caucasian women, the combined GSTP1 105IV/VV and CYP1B1 119AA genotypes resulted in a near 2-fold increase in risk (OR=1.96; 95% CI=1.04–3.72) and the three way combination of GSTP1 105IV/VV, CYP1B1 119AS/SS and GSTT1 null genotypes resulted in an almost 4-fold increase in risk (OR=3.97; 95% CI=1.27–12.40). These results suggest the importance of estrogen/carcinogen metabolic enzymes in the etiology of breast cancer, especially in women before the age of 60, as well as preventative measures such as smoking cessation. PMID:18425393

  15. CYP1B1 variants are associated with prostate cancer in non-Hispanic and Hispanic Caucasians.

    PubMed

    Beuten, Joke; Gelfond, Jonathan A L; Byrne, John J; Balic, Ivana; Crandall, AnaLisa C; Johnson-Pais, Teresa L; Thompson, Ian M; Price, Douglas K; Leach, Robin J

    2008-09-01

    Cytochrome P450 1B1 (CYP1B1) is involved in the activation of many carcinogens and in the metabolism of steroid hormones. We compared allele, genotype and haplotype frequencies of six single-nucleotide polymorphisms (SNPs) within CYP1B1 among non-Hispanic Caucasians (496 cases and 498 controls) and Hispanic Caucasians (153 cases and 240 controls). In the Hispanic Caucasians, the GG genotype for rs1056836 decreased the risk for prostate cancer (PCa) when compared with the CC genotype [odds ratio (OR) = 0.31, P = 0.04, 95% confidence interval (CI) = 0.10-0.96]. Among non-Hispanic Caucasian men with more aggressive PCa, the prevalence of several SNPs (rs2567206, rs2551188, rs2617266, rs10012 and rs1056836) was significantly associated with the disease status. A common C-G-C-C-G-A haplotype for rs2567206-rs2551188-rs2617266-rs10012-rs1056836-rs1800440 showed an inverse association with PCa risk in Hispanic Caucasians (OR = 0.19, P = 0.04, 95% CI = 0.04-0.95) and with aggressive disease status (i.e. Gleason score >or=7) in non-Hispanic Caucasian cases (OR = 0.64, P = 0.008, 95% CI = 0.47-0.89). In the non-Hispanic Caucasian cases, a second major haplotype T-A-T-G-C-A was positively associated with the high-grade disease status (OR = 1.77, P = 0.002, 95% CI = 1.24-2.53). Our findings suggest that genetic polymorphisms in CYP1B1 may modify the risk for PCa and support the role of CYP1B1 as a candidate gene for PCa.

  16. Quantitative assessment of the influence of CYP1B1 polymorphisms and head and neck squamous cell carcinoma risk.

    PubMed

    Shen, Ming; Hu, Yuan-Yuan; Hu, Yu-Kun; Xie, Long-Chuan; Xu, Xiao-Ming; Wu, Ming-Yue; Niu, Yu-Ming

    2014-04-01

    The associations between CYP1B1 polymorphisms and head and neck squamous cell carcinoma (HNSCC) risk have been conflicting. We therefore performed a meta-analysis to derive a more precise relationship. Six published case-control studies were collected; odds ratios (ORs) with 95% confidence interval (CI) were used to assess the association between CYP1B1 Leu432Val, Asn453Ser polymorphisms, and HNSCC risk. The Sensitivity analysis and publication bias also were performed to guarantee the statistical power. Overall, the pooled OR with 95% CIs indicated that CYP1B1 Leu432Val polymorphism was significantly related with HNSCC risk (for Val vs. Leu: OR = 1.13, 95% CI = 1.03-1.25, P = 0.014, P(heterogeneity) = 0.141; for Val/Val vs. Leu/Leu: OR = 1.30, 95% CI = 1.06-1.60, P = 0.013, P heterogeneity = 0.253; for Val/Val vs. Leu/Leu + Leu/Val: OR = 1.23, 95% CI = 1.05-1.46, P = 0.013, P(heterogeneity) = 0.456). The similar results were also been found in succeeding analysis of HWE and stratified analysis of Caucasian population. Furthermore, no significant association between CYP1B1 Asn453Ser polymorphism and HNSCC risk was found in this meta-analysis. In conclusion, our meta-analysis demonstrates that CYP1B1 Leu432Val polymorphism may be a risk factor for developing HNSCC.

  17. SLCO1B1 Variants and Angiotensin Converting Enzyme Inhibitor (Enalapril)-Induced Cough: a Pharmacogenetic Study.

    PubMed

    Luo, Jian-Quan; He, Fa-Zhong; Wang, Zhen-Min; Sun, Ning-Ling; Wang, Lu-Yan; Tang, Gen-Fu; Liu, Mou-Ze; Li, Qing; Chen, Xiao-Ping; Liu, Zhao-Qian; Zhou, Hong-Hao; Zhang, Wei

    2015-11-26

    Clinical observations suggest that incidence of cough in Chinese taking angiotensin converting enzyme inhibitors is much higher than other racial groups. Cough is the most common adverse reaction of enalapril. We investigate whether SLCO1B1 genetic polymorphisms, previously reported to be important determinants of inter-individual variability in enalapril pharmacokinetics, are associated with the enalapril-induced cough. A cohort of 450 patients with essential hypertension taking 10 mg enalapril maleate were genotyped for the functional SLCO1B1 variants, 388A > G (Asn130Asp, rs2306283) and 521T > C (Val174Ala, rs4149056). The primary endpoint was cough, which was recorded when participants were bothered by cough and respiratory symptoms during enalapril treatment without an identifiable cause. SLCO1B1 521C allele conferred a 2-fold relative risk of enalapril-induced cough (95% confidence interval [CI] = 1.34-3.04, P = 6.2 × 10(-4)), and haplotype analysis suggested the relative risk of cough was 6.94-fold (95% CI = 1.30-37.07, P = 0.020) in SLCO1B1*15/*15 carriers. Furthermore, there was strong evidence for a gene-dose effect (percent with cough in those with 0, 1, or 2 copy of the 521C allele: 28.2%, 42.5%, and 71.4%, trend P = 6.6 × 10(-4)). Our study highlights, for the first time, SLCO1B1 variants are strongly associated with an increased risk of enalapril-induced cough. The findings will be useful to provide pharmacogenetic markers for enalapril treatment.

  18. The CYP1B1 Leu432Val polymorphism contributes to lung cancer risk: evidence from 6501 subjects.

    PubMed

    Chen, Bo; Qiu, Li-Xin; Li, Yan; Xu, Wei; Wang, Xue-Li; Zhao, Wei-Hong; Wu, Jian-Qing

    2010-12-01

    The polymorphism of cytochrome P4501B1 (CYP1B1) codon 432 (rs1056836, CYP1B1*3, or Leu432Val) is thought to have a significant effect on lung cancer risk, but the results are inconsistent. In this meta-analysis, we assessed 9 published studies involving 6501 subjects that investigated the association between the CYP1B1 codon 432 polymorphism and risk of lung cancer. Overall, the CYP1B1 Leu/Val and Val/Val-variant genotypes were associated with a significantly increased risk of lung cancer in different genetic models (heterozygote comparison: OR=1.22; 95% CI=1.02-1.45, P(heterogeneity)=0.068; homozygote comparison: OR=1.41; 95% CI=1.08-1.85, P(heterogeneity)=0.071; dominant model comparison: OR=1.26; 95% CI=1.04-1.51, P(heterogeneity)=0.019; and recessive model comparison: OR=1.17; 95% CI=1.02-1.34, P(heterogeneity)=0.429). In the stratified analysis by ethnicity, significantly increased risks were found among Caucasians for Leu/Val vs Leu/Leu (OR=1.30; 95% CI=1.03-1.64; P(heterogeneity)=0.092), and dominant model (OR=1.35; 95% CI=1.03-1.77; P(heterogeneity)=0.015). However, no significant associations were found in both Europeans and African-Americans for all genetic models. In the subgroup analyses by smoking status, a significantly increased risk of lung cancer was found among smokers (dominant model: OR=1.46; 95% CI=1.08-1.83; P(heterogeneity)=0.175). However, we did not find any statistically significant association by subgroup analyses of pathological type. This meta-analysis suggests that the CYP1B1 Val allele is a low-penetrant risk factor for developing lung cancer.

  19. Interaction of human organic anion transporter polypeptides 1B1 and 1B3 with antineoplastic compounds.

    PubMed

    Marada, Venkata V V R; Flörl, Saskia; Kühne, Annett; Burckhardt, Gerhard; Hagos, Yohannes

    2015-03-06

    Antineoplastic compounds are used in the treatment of a variety of cancers. The effectiveness of an antineoplastic compound to exert its activity is largely dependent on transport proteins involved in the entry of the compound into the cells, and those which drive it out of the cell. Organic anion transporting polypeptide 1B1 (OATP1B1) and organic anion transporting polypeptide 1B3 (OATP1B3), belonging to the SLCO family of proteins, are specifically expressed in the sinusoidal membranes of the liver, and are known to interact with a variety of drugs. The present study deals with the interaction of these proteins with antineoplastic compounds routinely used in cancer chemotherapy. The proteins OATP1B1 and OATP1B3 were functionally characterized in stably transfected human embryonic kidney cells using [(3)H] labeled estrone 3-sulfate and [(3)H] labeled cholecystokinin octapeptide (CCK-8) as substrates, respectively. Substrate uptake experiments performed in the presence of antineoplastic compounds showed that vinblastine and paclitaxel strongly interacted with the OATP1B1 with Ki values of 10.2 μM and 0.84 μM, respectively. OATP1B3 showed highly significant interactions with a variety of antineoplastic compounds including chlorambucil, mitoxantrone, vinblastine, vincristine, paclitaxel and etoposide, with Ki values of 40.6 μM, 3.2 μM, 15.9 μM, 30.6 μM, 1.8 μM and 13.5 μM, respectively. We report several novel interactions of the transporter proteins OATP1B1 and OATP1B3 highlighting the need to investigate their role in drug-drug interactions and cancer chemotherapy.

  20. Differential effects of Glycyrrhiza species on genotoxic estrogen metabolism: licochalcone A downregulates P450 1B1 whereas isoliquiritigenin stimulates

    PubMed Central

    Dunlap, Tareisha L.; Wang, Shuai; Simmler, Charlotte; Chen, Shao-Nong; Pauli, Guido F.; Dietz, Birgit M.; Bolton, Judy L.

    2015-01-01

    Estrogen chemical carcinogenesis involves 4-hydroxylation of estrone/estradiol (E1/E2) by P450 1B1, generating catechol and quinone genotoxic metabolites that cause DNA mutations and initiate/promote breast cancer. Inflammation enhances this effect by up-regulating P450 1B1. The present study tested the three authenticated medicinal species of licorice, [Glycyrrhiza glabra (GG), G. uralensis (GU), and G. inflata (GI)], used by women as dietary supplements, for their anti-inflammatory activities and their ability to modulate estrogen metabolism. The pure compounds, liquiritigenin (LigF), its chalcone isomer isoliquiritigenin (LigC), and the GI specific licochalcone A (LicA) were also tested. The licorice extracts and compounds were evaluated for anti-inflammatory activity by measuring inhibition of iNOS activity in macrophage cells: GI > GG > GU and LigC ≅ LicA > LigF. The Michael acceptor chalcone LicA, is likely responsible for the anti-inflammatory activity of GI. A sensitive LC-MS/MS assay was employed to quantify estrogen metabolism by measuring 2-MeOE1 as non-toxic and 4-MeOE1 as genotoxic biomarkers in the non-tumorigenic human mammary epithelial cell line, MCF-10A. GG, GU, and LigC increased 4-MeOE1, whereas GI and LicA inhibited 2- and 4-MeOE1 levels. GG, GU (5 μg/mL), and LigC (1 μM) also enhanced P450 1B1 expression and activities, which was further increased by inflammatory cytokines (TNF-α and IFN-γ). LicA (1 μM, 10 μM) decreased cytokine- and TCDD-induced, P450 1B1 gene expression and TCDD-induced xenobiotic response element luciferase reporter (IC50=12.3 μM), suggesting an antagonistic effect on the aryl hydrocarbon receptor, which regulates P450 1B1. Similarly, GI (5 μg/mL) reduced cytokine- and TCDD-induced P450 1B1 gene expression. Collectively, these data suggest that of the three licorice species that are used in botanical supplements, GI represents the most promising chemopreventive licorice extract for women’s health. Additionally

  1. Linking organic anion transporting polypeptide 1B1 and 1B3 (OATP1B1 and OATP1B3) interaction profiles to hepatotoxicity - The hyperbilirubinemia use case.

    PubMed

    Kotsampasakou, Eleni; Escher, Sylvia E; Ecker, Gerhard F

    2017-03-30

    Hyperbilirubinemia is a pathological condition of excessive accumulation of conjugated or unconjugated bilirubin in blood. It has been associated with neurotoxicity and non-neural organ dysfunctions, while it can also be a warning of liver side effects. Hyperbilirubinemia can either be a result of overproduction of bilirubin due to hemolysis or dyserythropoiesis, or the outcome of impaired bilirubin elimination due to liver transporter malfunction or inhibition. There are several reports in literature that inhibition of organic anion transporting polypeptides 1B1 and 1B3 (OATP1B1 and OATP1B3) might lead to hyperbilirubinemia. In this study we created a set of classification models for hyperbilirubinemia, which, besides physicochemical descriptors, also include the output of classification models of human OATP1B1 and 1B3 inhibition. Models were based on either human data derived from public toxicity reports or animal data extracted from the eTOX database VITIC. The generated models showed satisfactory accuracy (68%) and area under the curve (AUC) for human data and 71% accuracy and 70% AUC for animal data. However, our results did not indicate strong association between OATP inhibition and hyperbilirubinemia, neither for humans nor for animals.

  2. Identification of Novel Inhibitors of Organic Anion Transporting Polypeptides 1B1 and 1B3 (OATP1B1 and OATP1B3) Using a Consensus Vote of Six Classification Models

    PubMed Central

    2015-01-01

    Organic anion transporting polypeptides 1B1 and 1B3 are transporters selectively expressed on the basolateral membrane of the hepatocyte. Several studies reveal that they are involved in drug–drug interactions, cancer, and hyperbilirubinemia. In this study, we developed a set of classification models for OATP1B1 and 1B3 inhibition based on more than 1700 carefully curated compounds from literature, which were validated via cross-validation and by use of an external test set. After combining several sets of descriptors and classifiers, the 6 best models were selected according to their statistical performance and were used for virtual screening of DrugBank. Consensus scoring of the screened compounds resulted in the selection and purchase of nine compounds as potential dual inhibitors and of one compound as potential selective OATP1B3 inhibitor. Biological testing of the compounds confirmed the validity of the models, yielding an accuracy of 90% for OATP1B1 and 80% for OATP1B3, respectively. Moreover, at least half of the new identified inhibitors are associated with hyperbilirubinemia or hepatotoxicity, implying a relationship between OATP inhibition and these severe side effects. PMID:26469880

  3. OATP1B1-related drug–drug and drug–gene interactions as potential risk factors for cerivastatin-induced rhabdomyolysis

    PubMed Central

    Tamraz, Bani; Fukushima, Hisayo; Wolfe, Alan R.; Kaspera, Rüdiger; Totah, Rheem A.; Floyd, James S.; Ma, Benjamin; Chu, Catherine; Marciante, Kristin D.; Heckbert, Susan R.; Psaty, Bruce M.; Kroetz, Deanna L.; Kwok, Pui-Yan

    2014-01-01

    Objective Genetic variation in drug metabolizing enzymes and membrane transporters as well as concomitant drug therapy can modulate the beneficial and the deleterious effects of drugs. We investigated whether patients exhibiting rhabdomyolysis who were taking cerivastatin possess functional genetic variants in SLCO1B1 and whether they were on concomitant medications that inhibit OATP1B1, resulting in accumulation of cerivastatin. Methods This study had three components: (a) resequencing the SLCO1B1 gene in 122 patients who developed rhabdomyolysis while on cerivastatin; (b) functional evaluation of the identified SLCO1B1 nonsynonymous variants and haplotypes in in-vitro HEK293/FRT cells stably transfected with pcDNA5/FRT empty vector, SLCO1B1 reference, variants, and haplotypes; and (c) in-vitro screening of 15 drugs commonly used among the rhabdomyolysis cases for inhibition of OATP1B1-mediated uptake of cerivastatin in HEK293/FRT cells stably transfected with reference SLCO1B1. Results The resequencing of the SLCO1B1 gene identified 54 variants. In-vitro functional analysis of SLCO1B1 nonsynonymous variants and haplotypes showed that the V174A, R57Q, and P155T variants, a novel frameshift insertion, OATP1B1*14 and OATP1B1*15 haplotype were associated with a significant reduction (P<0.001) in cerivastatin uptake (32, 18, 72, 3.4, 2.1 and 5.7% of reference, respectively). Furthermore, clopidogrel and seven other drugs were shown to inhibit OATP1B1-mediated uptake of cerivastatin. Conclusion Reduced function of OATP1B1 related to genetic variation and drug–drug interactions likely contributed to cerivastatin-induced rhabdomyolysis. Although cerivastatin is no longer in clinical use, these findings may translate to related statins and other substrates of OATP1B1. PMID:23652407

  4. Interaction of digitalis-like compounds with liver uptake transporters NTCP, OATP1B1, and OATP1B3.

    PubMed

    Gozalpour, Elnaz; Greupink, Rick; Wortelboer, Heleen M; Bilos, Albert; Schreurs, Marieke; Russel, Frans G M; Koenderink, Jan B

    2014-06-02

    Digitalis-like compounds (DLCs) such as digoxin, digitoxin, and ouabain, also known as cardiac glycosides, are among the oldest pharmacological treatments for heart failure. The compounds have a narrow therapeutic window, while at the same time, DLC pharmacokinetics is prone to drug-drug interactions at the transport level. Hepatic transporters organic anion transporting polypeptide (OATP) 1B1, OATP1B3, and Na(+)-dependent taurocholate co-transporting polypeptide (NTCP) influence the disposition of a variety of drugs by mediating their uptake from blood into hepatocytes. The interaction of digoxin, digitoxin, and ouabain with hepatic uptake transporters has been studied before. However, here, we systematically investigated a much wider range of structurally related DLCs for their capability to inhibit or to be transported by these transporters in order to better understand the relation between the activity and chemical structure of this compound type. We studied the uptake and inhibitory potency of a series of 14 structurally related DLCs in Chinese hamster ovary cells expressing NTCP (CHO-NTCP) and human embryonic kidney cells expressing OATP1B1 and OATP1B3 (HEK-OATP1B1 and HEK-OATP1B3). The inhibitory effect of the DLCs was measured against taurocholic acid (TCA) uptake in CHO-NTCP cells and against uptake of β-estradiol 17-β-d-glucuronide (E217βG) in HEK-OATP1B1 and HEK-OATP1B3 cells. Proscillaridin A was the most effective inhibitor of NTCP-mediated TCA transport (IC50 = 22 μM), whereas digitoxin and digitoxigenin were the most potent inhibitors of OATP1B1 and OAPTP1B3, with IC50 values of 14.2 and 36 μM, respectively. Additionally, we found that the sugar moiety and hydroxyl groups of the DLCs play different roles in their interaction with NTCP, OATP1B1, and OATP1B3. The sugar moiety decreases the inhibition of NTCP and OATP1B3 transport activity, whereas it enhances the inhibitory potency against OATP1B1. Moreover, the hydroxyl group at position 12

  5. OT2_cceccare_5: Peering into the engine of a jet-driven bowshock : TMC1B1

    NASA Astrophysics Data System (ADS)

    Ceccarelli, C.

    2011-09-01

    Jet-driven bowshocks seem to be rather ubiquitous in star-forming regions. If the large-scale bow is commonly observed and its kinematics, the actual engine of the outflow, the Mach disk region where the gas is accelerated, has never been detected until now. Recently, we have found observational evidence of the long-searched engine of outflows in the giant molecular bowshock TMC1B1 together with the driving jet, in Taurus (d=140 pc). which allows Herschel to resolve the cooling region of the shock. We propose to use Herschel to investigate the dynamics and physical structure of TMC1B1, a potential benchmark for jet-driven bowshocks studies.

  6. Synthesis and biological evaluation of new imidazo[2,1-b][1,3,4]thiadiazole-benzimidazole derivatives.

    PubMed

    Ramprasad, Jurupula; Nayak, Nagabhushana; Dalimba, Udayakumar; Yogeeswari, Perumal; Sriram, Dharmarajan; Peethambar, S K; Achur, Rajeshwara; Kumar, H S Santosh

    2015-05-05

    In this report, we describe the synthesis and biological evaluation of a new series of 2-(imidazo[2,1-b][1,3,4]thiadiazol-5-yl)-1H-benzimidazole derivatives (5a-ac). The molecules were analyzed by (1)H NMR, (13)C NMR, mass spectral and elemental data. The structure of one of the pre-final compounds, 6-(4-methoxyphenyl)-2-(4-methylphenyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde (4d) and that of a target compound, 2-[2-methyl-6-(4-methyl phenyl) imidazo[2,1-b][1,3,4]thiadiazol-5-yl]-1H-benzimidazole (5aa) were confirmed by single crystal XRD studies. All the target compounds were screened for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain. Seven (5c, 5d, 5l, 5p, 5r, 5z and 5aa) out of twenty nine compounds showed potent anti-tubercular activity with a MIC of 3.125 μg/mL. A p-substituted phenyl group (p-tolyl or p-chlorophenyl) in the imidazo[2,1-b][1,3,4]thiadiazole ring and/or a chloro group in the benzimidazole ring enhance anti-tuberculosis activity whereas a nitro group in the benzimidazole ring reduces the activity. In the antibacterial screening, compounds 5i, 5w and 5ac showed promising activity against the tested bacterial strains. Further, antifungal and antioxidant activities of these molecules were also investigated. In the cytotoxicity study, the active antitubercular compounds exhibited very low toxicity against a normal cell line.

  7. CYP1B1, MYOC, and LTBP2 Mutations in Primary Congenital Glaucoma Patients in the United States

    PubMed Central

    LIM, SING-HUI; TRAN-VIET, KHANH-NHAT; YANOVITCH, TAMMY L.; FREEDMAN, SHARON F.; KLEMM, THOMAS; CALL, WHITNEY; POWELL, CALDWELL; RAVICHANDRAN, AJAY; METLAPALLY, RAVIKANTH; NADING, ERICA B.; ROZEN, STEVE; YOUNG, TERRI L.

    2012-01-01

    PURPOSE To screen primary congenital glaucoma patients in the United States for sequence variants within the CYP1B1, LTBP2, and MYOC genes using Sanger and whole exome sequencing. DESIGN Retrospective case-control study. METHODS Fifty-seven primary congenital glaucoma patients (47 families), 71 unaffected family members of the primary congenital glaucoma probands, and 101 healthy unrelated individuals were recruited from a single institution. Sanger sequencing of the primary congenital glaucoma gene, CYP1B1, was performed on 47 proband deoxyribonucleic acid samples. Simultaneously, whole exome sequencing was conducted on 3 families, each including more than 1 affected individual. Concurrently, 33 of 47 primary congenital glaucoma probands with extended family deoxyribonucleic acid samples were screened for LTBP2 and MYOC gene mutations. Exome-sequenced variations were validated by additional Sanger sequencing to confirm segregation of filtered disease-causing single nucleotide variations. RESULTS Seven primary congenital glaucoma families (14.9%) manifested disease phenotypes attributable to CYP1B1 mutations. One primary congenital glaucoma family possessed homozygous mutant alleles, whereas 6 families carried compound heterozygous mutations. Five novel combinations of compound heterozygous mutations were identified, of which 2 combinations were found with whole exome sequencing. No disease-causing mutations withinthe LTBP2and MYOCgenes were discovered. CONCLUSIONS This study analyzed CYP1B1, LTBP2, and MYOC mutations in a cohort of primary congenital glaucoma patients from the United States, applying whole exome sequencing as a complementary tool to Sanger sequencing. Whole exome sequencing, coupled with Sanger sequencing, may identify novel genes in primary congenital glaucoma patients who have no mutations in known primary congenital glaucoma genes. PMID:23218701

  8. CYP1B1 Leu432Val polymorphism and colorectal cancer risk among Caucasians: a meta-analysis.

    PubMed

    Xie, Yong; Liu, Guo-Qing; Miao, Xiong-Ying; Liu, Yi; Zhou, Wei; Zhong, De-Wu

    2012-06-01

    Studies investigating the association between cytochrome P450 1B1 (CYP1B1) Leu432Val (432 C/G, rs1056836) polymorphism and colorectal cancer (CRC) risk report conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for CYP1B1 polymorphism and CRC were calculated in a fixed-effects model and a random-effects model when appropriate. The pooled ORs were performed for co-dominant model (GG vs. CC, GC vs. CC), dominant model (GG + GC vs. CC), and recessive model (GG vs. GC + CC). This meta-analysis included ten case-control studies, which included 8,466 CRC cases and 9,301 controls. Overall, the variant genotypes (GG and GC) of the 432 C/G were not associated with CRC risk when compared with the wild-type CC homozygote (GG vs. CC, OR = 1.01, 95% CI = 0.93-1.10; GC vs. CC, OR = 0.97, 95% CI = 0.90-1.04), without any between-study heterogeneity. Similarly, no associations were found in the dominant and recessive models (dominant model, OR = 0.98, 95% CI = 0.92-1.05; recessive model, OR = 1.03, 95% CI = 0.96-1.11). Limiting the analysis to the studies within Hardy-Weinberg equilibrium, the results were persistent and robust. When stratifying for country, matched control and source of controls, no evidence of significant association was observed in any subgroup. No publication bias was found in the present study. No association is found between the CYP1B1 Leu432Val polymorphism and risk of CRC among Caucasians.

  9. Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma

    PubMed Central

    Plasilova, M.; Stoilov, I.; Sarfarazi, M.; Kadasi, L.; Ferakova, E.; Ferak, V.

    1999-01-01

    Primary congenital glaucoma (PCG) is an autosomal recessive eye disease that occurs at an unusually high frequency in the ethnic isolate of Roms (Gypsies) in Slovakia. Recently, we linked the disease in this population to the GLC3A locus on 2p21. At this locus, mutations in the cytochrome P4501B1 (CYP1B1) gene have been identified as a molecular basis for this condition. Here, we report the results of CYP1B1 mutation screening of 43 PCG patients from 26 Slovak Rom families. A homozygous G→A transition at nucleotide 1505 in the highly conserved region of exon 3 was detected in all families. This mutation results in the E387K substitution, which affects the conserved K helix region of the cytochrome P450 molecule. Determination of the CYP1B1 polymorphic background showed a common DNA haplotype in all patients, thus indicating that the E387K mutation in Roms has originated from a single ancestral mutational event. The Slovak Roms represent the first population in which PCG is found to result from a single mutation in the CYP1B1 gene, so that a founder effect is the most plausible explanation of its increased incidence. An ARMS-PCR assay has been developed for fast detection of this mutation, thus allowing direct DNA based prenatal diagnosis as well as gene carrier detection in this particular population. Screening of 158 healthy Roms identified 17 (10.8%) mutation carriers, indicating that the frequency of PCG in this population may be even higher than originally estimated.


Keywords: primary congenital glaucoma (PCG); cytochrome P4501B1; Roms (Gypsies); founder effect PMID:10227395

  10. Modeling Organic Anion-Transporting Polypeptide 1B1 Inhibition to Elucidate Interaction Risks in Early Drug Design.

    PubMed

    Zamora, Ismael; Winiwarter, Susanne

    2016-10-01

    The importance of transporter proteins for the disposition of drugs has become increasingly apparent during the past decade. A noted drug-drug interaction risk is the inhibition of organic anion-transporting polypeptides (OATPs), key transporters for the liver uptake of the widely used statins. We show here the development of a ligand-based in silico model for interaction with OATP1B1, an important representative of the OATP family. The model is based on a structural overlay of 6 known OATP1B1 inhibitors. A data set of about 150 compounds with published OATP1B1 inhibition data was compared to the resulting "transportophor," and a similarity threshold was defined to distinguish between active and inactive molecules. In addition, using a statistical model based on physicochemical properties of the compounds as prefilter was found to enhance the overall predictivity of the model (final accuracy 0.73, specificity 074, and sensitivity 0.71, based on 126 compounds). The combined model was validated using an in-house data set (accuracy, specificity, and sensitivity were 0.63, 0.59, and 0.78, respectively; 62 compounds). The model gives also a structural overlay to the most similar template enabling visualization of where a change in a given structure might reduce the interaction with the transporter.

  11. Polymorphic variation of CYP1A1 and CYP1B1 genes in a Haryana population.

    PubMed

    Giri, Shiv Kumar; Yadav, Anita; Kumar, Anil; Dev, Kapil; Gulati, Sachin; Gupta, Ranjan; Aggarwal, Neeraj; Gautam, Sanjeev Kumar

    2013-12-01

    Cytochrome P450 (CYP) 1A1 and CYP1B1 are important phase I xenobiotic metabolizing enzymes involved in the metabolism of numbers of toxins, endogenous hormones, and pharmaceutical drugs. Polymorphisms in these phase I genes can alter enzyme activity and are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. Their genotypes may also display ethnicity-dependent population frequencies. The present study was aimed to determine the frequencies of commonly known functional polymorphisms of CYP1A1 and CYP1B1 genes in a Haryana state population of North India. The allelic frequency of CYP1A1 polymorphism m1 (MspI) was 29.65% and m2 (Ile(462)Val) was 24.85%. The frequency of CYP1B1 polymorphism m1 (Val(432)Leu) was 45.85% and m2 (Asn(453)Ser) was 16.2%. We observed inter- and intra-ethnic variation in the frequency distribution of these polymorphisms. Analysis of polymorphisms in these genes might help in predicting the risk of cancer. Our results emphasize the need for more such studies in high-risk populations.

  12. ssociation of Cytochrome P450-1B1 Gene Polymorphisms with Risk of Breast Cancer: an Egyptian Study.

    PubMed

    Ibrahim, Mona H; Rashed, Reham A; Hassan, Naglaa M; Al-Azhary, Nevin M; Salama, Asmaa I; Mostafa, Marwa N

    2016-01-01

    It is thought that population characteristics of breast cancer may be due to a variation in the frequency of different alleles of genes such as CYP1B1. We aimed to determine the association of CYP1B1 polymorphisms in 200 breast cancer cases and 40 controls by PCR-RFLP. Frequencies were assessed with clinical and risk factors in Egyptian patients. The genotype LV and the Leu allele frequencies for patients and controls were 42.9% and 50%, and 52.9% and 53.3%, respectively), with no significant differences observed (P values = 0.8 and 0.6, respectively). There was also no significant association between genotypes and any risk factors for cases (>0.05) except laterality and metastasis of the tumor (P values=0.006 and 0.06, respectively). The CYP1B1 polymorphism Val432Leu was not associated with breast cancer in Egypt, but may provide clues for future studies into early detection of the disease.

  13. Functional variants in CYP1B1, KRAS and MTHFR genes are associated with shorter telomere length in postmenopausal women.

    PubMed

    Cerne, Jasmina Z; Pohar-Perme, Maja; Cerkovnik, Petra; Gersak, Ksenija; Novakovic, Srdjan

    2015-07-01

    Estrogens and antioxidants indirectly alleviate telomere attrition. However, available clinical data on the association between hormone exposure and telomere length are inconclusive. In the present study, we examined the effects of exogenous estrogen use and of some genetic factors implicated in estrogen metabolism and oxidative stress response on mean leukocyte telomere length. We studied 259 postmenopausal women. Genotyping was conducted for CYP1B1 (rs1056836), COMT (rs4680), GSTP1 (rs1695), MnSOD (rs4880), KRAS (rs61764370), and MTHFR (rs1801133 and rs1801131) polymorphisms. Mean leukocyte telomere length was measured using a quantitative real-time PCR assay. In multivariate analysis we found no association between oral contraceptives or hormone replacement therapy (HRT) and mean leukocyte telomere length. The presence of variant alleles in CYP1B1, KRAS and MTHFR genes was statistically significantly associated with shorter mean leukocyte telomere length. Further, the data provided evidence for the effect modification of the association between HRT and mean leukocyte telomere length by the CYP1B1, KRAS and MTHFR genotypes. Our findings suggest that functionally relevant genetic variants within estrogen and folate metabolic pathways may influence telomere length. We propose these genetic factors should be taken into consideration when interpreting associations between hormone exposure and telomere length.

  14. CYP1A1 and CYP1B1 expressions in medulloblastoma cells are AhR-independent and have no direct link with resveratrol-induced differentiation and apoptosis.

    PubMed

    Wu, Mo-Li; Li, Hong; Wu, Da-Chang; Wang, Xiao-Wei; Chen, Xiao-Yan; Kong, Qing-You; Ma, Jing-Xin; Gao, Ying; Liu, Jia

    Resveratrol induces apoptosis and regulates CYP1A1 and CYP1B1 expression in human medulloblastoma cells. To elucidate the potential correlation of their expressions with the anti-medulloblastoma effects of resveratrol, human medulloblastoma cells, UW228-3, were treated with CYP1A1 selective inhibitor (alpha-naphthoflavone, alpha-NF), selective CYP1A1/1A2 inducer (beta-naphthoflavone, beta-NF) and their combination with resveratrol, respectively. The influences of those treatments on the expressions of CYP1A1, 1A2 and 1B1 as well as the cell growth, differentiation and death were analyzed. It was found that neither alpha-NF nor beta-NF had any effect on cell growth. alpha-NF inhibited resveratrol-induced CYP1A1 expression without interfering cell differentiation and apoptosis. beta-NF could up-regulate resveratrol-induced CYP1A1 expression but not enhance the anti-cancer effects of resveratrol. CYP1A2 was undetectable in the cells irrespective to the treatments. Aryl hydrocarbon receptor (AhR) was absent in UW228-3 cells under normal culture and treated with resveratrol but induced by both alpha- and beta-NF. Immunohistochemical examination performed on 11 pairs of human medulloblastoma and noncancerous cerebellar tissues revealed that AhR was undetectable in either of them, whereas CYP1A1 was expressed in cerebellum but down-regulated or diminished in their malignant counterparts. Our data suggest for the first time that CYP1A1 and 1B1 expressions in human medulloblastoma cells are AhR-independent and have no direct links with resveratrol-induced differentiation and apoptosis. Appearance of CYP1A1 expression may reflect a more maturated status and a better prognosis of medulloblastomas.

  15. PAHs Target Hematopoietic Linages in Bone Marrow through Cyp1b1 Primarily in Mesenchymal Stromal Cells but Not AhR: A Reconstituted In Vitro Model

    PubMed Central

    Larsen, Michele Campaigne; N'jai, Alhaji; Czuprynski, Charles J.

    2016-01-01

    7,12-Dimethylbenz(a)anthracene (DMBA) rapidly suppresses hematopoietic progenitors, measured as colony forming units (CFU), in mouse bone marrow (BM) leading to mature cell losses as replenishment fails. These losses are mediated by Cyp1b1, independent of the AhR, despite induction of Cyp1b1. BM mesenchymal progenitor cells (MPC) may mediate these responses since basal Cyp1b1 is minimally induced. PreB colony forming unit activity (PreB CFU) is lost within 24 hours in isolated BM cells (BMC) unless cocultured with cells derived from primary MPC (BMS2 line). The mouse embryonic OP9 line, which provides more efficient coculture support, shares similar induction-resistant Cyp1b1 characteristics. This OP9 support is suppressed by DMBA, which is then prevented by Cyp1b1 inhibitors. OP9-enriched medium partially sustains CFU activities but loses DMBA-mediated suppression, consistent with mediation by OP9 Cyp1b1. PreB CFU activity in BMC from Cyp1b1-ko mice has enhanced sensitivity to DMBA. BMC gene expression profiles identified cytokines and developmental factors that are substantially changed in Cyp1b1-ko mice. DMBA had few effects in WT mice but systematically modified many clustered responses in Cyp1b1-ko mice. Typical BMC AhR-responsive genes were insensitive to Cyp1b1 deletion. TCDD replicated Cyp1b1 interventions, suggesting alternative AhR mediation. Cyp1b1 also diminishes oxidative stress, a key cause of stem cell instability. PMID:27891153

  16. 6β-hydroxytestosterone, a cytochrome P450 1B1 metabolite of testosterone, contributes to angiotensin II-induced hypertension and its pathogenesis in male mice.

    PubMed

    Pingili, Ajeeth K; Kara, Mehmet; Khan, Nayaab S; Estes, Anne M; Lin, Zongtao; Li, Wei; Gonzalez, Frank J; Malik, Kafait U

    2015-06-01

    Previously, we showed that Cyp1b1 gene disruption minimizes angiotensin II-induced hypertension and associated pathophysiological changes in male mice. This study was conducted to test the hypothesis that cytochrome P450 1B1-generated metabolites of testosterone, 6β-hydroxytestosterone and 16α-hydroxytestosterone, contribute to angiotensin II-induced hypertension and its pathogenesis. Angiotensin II infusion for 2 weeks increased cardiac cytochrome P450 1B1 activity and plasma levels of 6β-hydroxytestosterone, but not 16α-hydroxytestosterone, in Cyp1b1(+/+) mice without altering Cyp1b1 gene expression; these effects of angiotensin II were not observed in Cyp1b1(-/-) mice. Angiotensin II-induced increase in systolic blood pressure and associated cardiac hypertrophy, and fibrosis, measured by intracardiac accumulation of α-smooth muscle actin, collagen, and transforming growth factor-β, and increased nicotinamide adenine dinucleotide phosphate oxidase activity and production of reactive oxygen species; these changes were minimized in Cyp1b1(-/-) or castrated Cyp1b1(+/+) mice, and restored by treatment with 6β-hydroxytestoterone. In Cyp1b1(+/+) mice, 6β-hydroxytestosterone did not alter the angiotensin II-induced increase in systolic blood pressure; the basal systolic blood pressure was also not affected by this agent in either genotype. Angiotensin II or castration did not alter cardiac, angiotensin II type 1 receptor, angiotensin-converting enzyme, Mas receptor, or androgen receptor mRNA levels in Cyp1b1(+/+) or in Cyp1b1(-/-) mice. These data suggest that the testosterone metabolite, 6β-hydroxytestosterone, contributes to angiotensin II-induced hypertension and associated cardiac pathogenesis in male mice, most probably by acting as a permissive factor. Moreover, cytochrome P450 1B1 could serve as a novel target for developing agents for treating renin-angiotensin and testosterone-dependent hypertension and associated pathogenesis in males.

  17. Mercury modulates the cytochrome P450 1a1, 1a2 and 1b1 in C57BL/6J mice: in vivo and in vitro studies

    SciTech Connect

    Amara, Issa E.A.; Anwar-Mohamed, Anwar; Abdelhamid, Ghada; El-Kadi, Ayman O.S.

    2013-02-01

    In the current study C57BL/6J mice were injected intraperitoneally with Hg{sup 2+} in the absence and presence of TCDD. After 6 and 24 h the liver was harvested and the expression of Cyps was determined. In vitro, isolated hepatocytes were incubated with TCDD in the presence and absence of Hg{sup 2+}. At the in vivo level, Hg{sup 2+} significantly decreased the TCDD-mediated induction of Cyps at 6 h while potentiating their levels at 24 h. In vitro, Hg{sup 2+} significantly inhibited the TCDD-mediated induction of Cyp1a1 in a concentration- and time-dependent manner. Interestingly, Hg{sup 2+} increased the serum hemoglobin (Hb) levels in mice treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the AhR-dependent luciferase activity with a subsequent increase in Cyp1a1 protein and catalytic activity levels. Importantly, when hepatocytes were treated for 2 h with Hg{sup 2+} in the presence of TCDD, then the medium was replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. In addition, Hg{sup 2+} increased heme oxygenase-1 (HO-1) mRNA, which coincided with a decrease in the Cyp1a1 activity level. When the competitive HO-1 inhibitor, tin mesoporphyrin was applied to the hepatocytes there was a partial restoration of Hg{sup 2+}-mediated inhibition of Cyp1a1 activity. In conclusion, we demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by Hg{sup 2+} in C57BL/6J mice livers and isolated hepatocytes. Moreover, this study implicates Hb as an in vivo specific modulator of Cyp1 family. -- Highlights: ► In vivo, Hg{sup 2+} decreased the Cyps at 6 h while potentiating their levels at 24 h. ► In vitro, Hg{sup 2+} significantly inhibited the TCDD-mediated induction of Cyps. ► Hg{sup 2+} increased the serum Hb levels in animals treated for 24 h. ► Hb potentiated the TCDD-mediated effect on Cyps. ► Tin mesoporphyrin partially restored Hg{sup 2+}-mediated inhibition of Cyp1a1.

  18. A spectrum of CYP1B1 mutations associated with primary congenital glaucoma in families of Pakistani descent

    PubMed Central

    Rauf, Bushra; Irum, Bushra; Kabir, Firoz; Firasat, Sabika; Naeem, Muhammad Asif; Khan, Shaheen N; Husnain, Tayyab; Riazuddin, Sheikh; Akram, Javed; Riazuddin, S Amer

    2016-01-01

    Glaucoma is the second leading cause of blindness, affecting ~65 million people worldwide. We identified and ascertained a large cohort of inbred families with multiple individuals manifesting cardinal symptoms of primary congenital glaucoma (PCG) to investigate the etiology of the disease at a molecular level. Ophthalmic examinations, including slit-lamp microscopy and applanation tonometry, were performed to characterize the causal phenotype and confirm that affected individuals fulfilled the diagnostic criteria for PCG. Subsequently, exclusion analysis was completed with fluorescently labeled short tandem repeat markers, followed by Sanger sequencing to identify pathogenic variants. Exclusion analysis suggested linkage to the CYP1B1 locus, with positive two-point logarithm of odds scores in 23 families, while Sanger sequencing identified a total of 11 variants, including two novel mutations, in 23 families. All mutations segregated with the disease phenotype in their respective families. These included the following seven missense mutations: p.Y81N, p.E229K, p.R368H, p.R390H, p.W434R, p.R444Q and p.R469W, as well as one nonsense mutation, p.Q37*, and three frameshift mutations, p.W246Lfs81*, p.T404Sfs30* and p.P442Qfs15*. In conclusion, we identified a total of 11 mutations, reconfirming the genetic heterogeneity of CYP1B1 in the pathogenesis of PCG. To the best of our knowledge, this is the largest study investigating the contribution of CYP1B1 to the pathogenesis of PCG in the Pakistani population. PMID:27508083

  19. Menopausal complaints in Slovak midlife women and the impact of CYP1B1 polymorphism on their incidence.

    PubMed

    Luptáková, Lenka; Sivtáková, Daniela; Cernanová, Veronika; Cvicelová, Marta

    2012-01-01

    A wide variety of symptoms have been attributed to menopause, negatively influencing women's physical and psychological health. In addition to lifestyle parameters and personal history, genetic factors are considered to be the main source of this variation. This study aims to investigate the incidence of menopausal symptoms among midlife women according to their menopausal status, and to evaluate the contribution to their manifestation from CYP1B1 Leu432Val polymorphism as a predisposing factor for menopausal symptoms. The studied cohort consisted of 299 women ranging from 39 to 59 years of age. Women were recruited from the western and middle parts of Slovakia, and all participants completed a menopause-specific questionnaire and provided blood or saliva samples for genotyping. Our results indicated that all women are at risk of typical menopausal symptoms, but there is a higher number of postmenopausal women affected than premenopausal ones. Regression analysis showed that the CYP1B1 Leu/Leu genotype can increase the experience of bloated stomach and facial hair increase in all the sampled women, while the Leu/Leu genotype may increase experience of palpitations and involuntary urination in the premenopausal women. The Leu/Leu genotype may increase the experience of nausea, bloated stomach, and vaginal dryness in peri- and postmenopausal women. We determined that women with the Leu/Leu, or Leu/Val genotypes were approximately five times more likely to suffer from vaginal dryness than the Val/Val women (OR = 4.948; 95% CI, 1.259-19.447). We therefore suggest that CYP1B1 Leu432Val polymorphism could be involved in individual susceptibility to menopausal symptoms in Slovak midlife women.

  20. Hypervelocity Impact (HVI). Volume 8; Tile Small Targets A-1, Ag-1, B-1, and Bg-1

    NASA Technical Reports Server (NTRS)

    Gorman, Michael R.; Ziola, Steven M.

    2007-01-01

    During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Targets A-1, Ag-1, B-1, and Bg-1 was to study hypervelocity impacts on the reinforced Shuttle Heat Shield Tiles of the Wing. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

  1. Current evidence on the relationship between CYP1B1 polymorphisms and lung cancer risk: a meta-analysis.

    PubMed

    Xu, Wenhuan; Zhou, Yunhai; Hang, Xiaosheng; Shen, Di

    2012-03-01

    The association between single-nucleotide polymorphisms (SNPs) of the CYP1B1 gene and lung cancer risk is still ambiguous. In this meta analysis, we assessed 10 case-control studies included 7,067 cases and 9,374 controls of the association between CYP1B1 SNPs of Leu432Val (rs1056836, 432C>G), Asn453Ser (rs1800440, 453A>G), Ala119Ser (rs1056827, 119G>T), Arg48Gly (rs10012, 48C>G) and the risk of lung cancer. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of association between the polymorphism and lung cancer risk under codominant model, dominant model and additive model respectively. Although there were limitations, this meta analysis indicated that individuals with 432GG genotype had a 39.7% higher risk of having lung cancer than those with the 432CC genotype, and individuals with the 432G allele had a 26.3% increased risk as well. An increased risk of lung cancer of 2.13 fold was observed in individuals with 119TT genotype. For Arg48Gly, individuals with 48GG genotype had a significantly increased risk of lung cancer compared with individuals with 48CC (OR 3.859; 95% CI 2.536-5.87). Elevated risk of lung cancer were observed in dominant model (OR 2.115; 95% CI 1.653-2.705) as well. The risk of lung cancer was elevated as the frequency of G allele increased in additive model (P = 0.000). For individuals with the polymorphism at codon 453, no evidence of such association was observed. Furthermore, a possible association between the CYP1B1 polymorphism at codon 432 and the lung cancer could be detected in individuals of Caucasian origin, while a negative association was suggested in Asians and African-Americans. An increased lung cancer risk was also found in women with polymorphism at codon 453. These results are supportive for the hypothesis that the CYP1B1 432GG, 119TT and 48GG genotypes are low-penetrance risk factors for developing lung cancer, and further studies are needed to validate these associations.

  2. miR-27b synergizes with anticancer drugs via p53 activation and CYP1B1 suppression

    PubMed Central

    Mu, Wenjing; Hu, Chaobo; Zhang, Haibin; Qu, Zengqiang; Cen, Jin; Qiu, Zhixin; Li, Chao; Ren, Haozhen; Li, Yixue; He, Xianghuo; Shi, Xiaolei; Hui, Lijian

    2015-01-01

    Liver and kidney cancers are notorious for drug resistance. Due to the complexity, redundancy and interpatient heterogeneity of resistance mechanisms, most efforts targeting a single pathway were unsuccessful. Novel personalized therapies targeting multiple essential drug resistance pathways in parallel hold a promise for future cancer treatment. Exploiting the multitarget characteristic of microRNAs (miRNAs), we developed a new therapeutic strategy by the combinational use of miRNA and anticancer drugs to increase drug response. By a systems approach, we identified that miR-27b, a miRNA deleted in liver and kidney cancers, sensitizes cancer cells to a broad spectrum of anticancer drugs in vitro and in vivo. Functionally, miR-27b enhances drug response by activating p53-dependent apoptosis and reducing CYP1B1-mediated drug detoxification. Notably, miR-27b promotes drug response specifically in patients carrying p53-wild-type or CYP1B1-high signature. Together, we propose that miR-27b synergizes with anticancer drugs in a defined subgroup of liver and kidney cancer patients. PMID:25698578

  3. CYP1B1 and CYP19 gene polymorphisms and breast cancer incidence: no association in the ARIC study.

    PubMed

    Thyagarajan, Bharat; Brott, Marcia; Mink, Pamela; Folsom, Aaron R; Anderson, Kristin E; Oetting, William Starr; Gross, Myron

    2004-04-30

    We conducted a nested case control study of 178 incident breast cancer cases and 356 controls in the Atherosclerosis Risk in Communities study. We evaluated the association between breast cancer and Val432Leu polymorphism in the CYP1B1 gene and the tetranucleotide repeats in intron 4 of the CYP19 gene. After adjustment for height, age at menopause, age at menarche, BMI, HRT, and alcohol intake, carriers of the Val/Leu or Val/Val genotype had a 1.45 fold (95% CI 0.85-2.47) greater odds of breast cancer than Leu/Leu carriers. There was no association of the breast cancer with any individual CYP19 allele. Compared to individuals homozygous with the 167 allele, odds ratios were close to 1.0 for the 167 heterozygous genotype and for the remaining tetranucleotide repeats combined. Our data shows no association between breast cancer and the Leu432Val polymorphism of the CYP1B1 gene or the tetranucleotide repeats of the CYP19 gene.

  4. CYP1A1 and CYP1B1 genetic polymorphisms and uterine leiomyoma risk in Chinese women

    PubMed Central

    Ye, Yi; Cheng, Xiao; Luo, Hai-Bo; Liu, Li; Li, Ying-Bi

    2008-01-01

    Purpose The aim of the study was to evaluate the association of CYP1A1 and CYP1B1 polymorphisms with uterine leiomyoma in Chinese women. Methods We investigated 100 women with clinically diagnosed uterine leiomyoma and 110 healthy normal subjects from Chinese women. The genetic distribution of two CYP1A1 polymorphisms at MspI, Ile462Val and four CYP1B1 polymorphisms at Arg48Gly, Ala119Ser, Leu432Val, Asp449Asp were analyzed by polymerase chain reaction–restriction fragment length polymorphism and DNA sequencing method. Results All the SNPs showed polymorphisms in Chinese women. The genotype A/G and the allele G on Ile462Val was significantly different between uterine leiomyoma patients and controls (P < 0.05). Conclusion These results suggest that the genotype of CYP1A1 Ile462Val was associated with the increased risk of uterine leiomyomas in Chinese women. PMID:18763031

  5. Downregulation of Organic Anion Transporting Polypeptide (OATP) 1B1 Transport Function by Lysosomotropic Drug Chloroquine: Implication in OATP-Mediated Drug-Drug Interactions.

    PubMed

    Alam, Khondoker; Pahwa, Sonia; Wang, Xueying; Zhang, Pengyue; Ding, Kai; Abuznait, Alaa H; Li, Lang; Yue, Wei

    2016-03-07

    Organic anion transporting polypeptide (OATP) 1B1 mediates the hepatic uptake of many drugs including lipid-lowering statins. Decreased OATP1B1 transport activity is often associated with increased systemic exposure of statins and statin-induced myopathy. Antimalarial drug chloroquine (CQ) is also used for long-term treatment of rheumatoid arthritis and systemic lupus erythematosus. CQ is lysosomotropic and inhibits protein degradation in lysosomes. The current studies were designed to determine the effects of CQ on OATP1B1 protein degradation, OATP1B1-mediated transport in OATP1B1-overexpressing cell line, and statin uptake in human sandwich-cultured hepatocytes (SCH). Treatment with lysosome inhibitor CQ increased OATP1B1 total protein levels in HEK293-OATP1B1 cells and in human SCH as determined by OATP1B1 immunoblot. In HEK293-FLAG-tagged OATP1B1 stable cell line, co-immunofluorescence staining indicated that intracellular FLAG-OATP1B1 is colocalized with lysosomal associated membrane glycoprotein (LAMP)-2, a marker protein of late endosome/lysosome. Enlarged LAMP-2-positive vacuoles with FLAG-OATP1B1 protein retained inside were readily detected in CQ-treated cells, consistent with blocking lysosomal degradation of OATP1B1 by CQ. In HEK293-OATP1B1 cells, without pre-incubation, CQ concentrations up to 100 μM did not affect OATP1B1-mediated [(3)H]E217G accumulation. However, pre-incubation with CQ at clinically relevant concentration(s) significantly decreased [(3)H]E217G and [(3)H]pitavastatin accumulation in HEK293-OATP1B1 cells and [(3)H]pitavastatin accumulation in human SCH. CQ pretreatment (25 μM, 2 h) resulted in ∼1.9-fold decrease in Vmax without affecting Km of OATP1B1-mediated [(3)H]E217G transport in HEK293-OATP1B1 cells. Pretreatment with monensin and bafilomycin A1, which also have lysosome inhibition activity, significantly decreased OATP1B1-mediated transport in HEK293-OATP1B1 cells. Pharmacoepidemiologic studies using data from the U.S. Food

  6. Preference of Conjugated Bile Acids over Unconjugated Bile Acids as Substrates for OATP1B1 and OATP1B3.

    PubMed

    Suga, Takahiro; Yamaguchi, Hiroaki; Sato, Toshihiro; Maekawa, Masamitsu; Goto, Junichi; Mano, Nariyasu

    2017-01-01

    Bile acids, the metabolites of cholesterol, are signaling molecules that play critical role in many physiological functions. They undergo enterohepatic circulation through various transporters expressed in intestine and liver. Human organic anion-transporting polypeptides (OATP) 1B1 and OATP1B3 contribute to hepatic uptake of bile acids such as taurocholic acid. However, the transport properties of individual bile acids are not well understood. Therefore, we selected HEK293 cells overexpressing OATP1B1 and OATP1B3 to evaluate the transport of five major human bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, ursodeoxycholic acid, lithocholic acid) together withtheir glycine and taurine conjugates via OATP1B1 and OATP1B3. The bile acids were quantified by liquid chromatography-tandem mass spectrometry. The present study revealed that cholic acid, chenodeoxyxcholic acid, and deoxycholic acid were transported by OATP1B1 and OATP1B3, while ursodeoxycholic acid and lithocholic acid were not significantly transported by OATPs. However, all the conjugated bile acids were taken up rapidly by OATP1B1 and OATP1B3. Kinetic analyses revealed the involvement of saturable OATP1B1- and OATP1B3-mediated transport of bile acids. The apparent Km values for OATP1B1 and OATP1B3 of the conjugated bile acids were similar (0.74-14.7 μM for OATP1B1 and 0.47-15.3 μM for OATP1B3). They exhibited higher affinity than cholic acid (47.1 μM for OATP1B1 and 42.2 μM for OATP1B3). Our results suggest that conjugated bile acids (glycine and taurine) are preferred to unconjugated bile acids as substrates for OATP1B1 and OATP1B3.

  7. Preference of Conjugated Bile Acids over Unconjugated Bile Acids as Substrates for OATP1B1 and OATP1B3

    PubMed Central

    Suga, Takahiro; Sato, Toshihiro; Maekawa, Masamitsu; Goto, Junichi; Mano, Nariyasu

    2017-01-01

    Bile acids, the metabolites of cholesterol, are signaling molecules that play critical role in many physiological functions. They undergo enterohepatic circulation through various transporters expressed in intestine and liver. Human organic anion-transporting polypeptides (OATP) 1B1 and OATP1B3 contribute to hepatic uptake of bile acids such as taurocholic acid. However, the transport properties of individual bile acids are not well understood. Therefore, we selected HEK293 cells overexpressing OATP1B1 and OATP1B3 to evaluate the transport of five major human bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, ursodeoxycholic acid, lithocholic acid) together withtheir glycine and taurine conjugates via OATP1B1 and OATP1B3. The bile acids were quantified by liquid chromatography-tandem mass spectrometry. The present study revealed that cholic acid, chenodeoxyxcholic acid, and deoxycholic acid were transported by OATP1B1 and OATP1B3, while ursodeoxycholic acid and lithocholic acid were not significantly transported by OATPs. However, all the conjugated bile acids were taken up rapidly by OATP1B1 and OATP1B3. Kinetic analyses revealed the involvement of saturable OATP1B1- and OATP1B3-mediated transport of bile acids. The apparent Km values for OATP1B1 and OATP1B3 of the conjugated bile acids were similar (0.74–14.7 μM for OATP1B1 and 0.47–15.3 μM for OATP1B3). They exhibited higher affinity than cholic acid (47.1 μM for OATP1B1 and 42.2 μM for OATP1B3). Our results suggest that conjugated bile acids (glycine and taurine) are preferred to unconjugated bile acids as substrates for OATP1B1 and OATP1B3. PMID:28060902

  8. 42 CFR 2a.6 - Issuance of Confidentiality Certificates; single project limitation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Issuance of Confidentiality Certificates; single project limitation. 2a.6 Section 2a.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PROTECTION OF IDENTITY-RESEARCH SUBJECTS § 2a.6 Issuance of...

  9. 42 CFR 2a.6 - Issuance of Confidentiality Certificates; single project limitation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Issuance of Confidentiality Certificates; single project limitation. 2a.6 Section 2a.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PROTECTION OF IDENTITY-RESEARCH SUBJECTS § 2a.6 Issuance of...

  10. 42 CFR 2a.6 - Issuance of Confidentiality Certificates; single project limitation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Issuance of Confidentiality Certificates; single project limitation. 2a.6 Section 2a.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PROTECTION OF IDENTITY-RESEARCH SUBJECTS § 2a.6 Issuance of...

  11. 42 CFR 2a.6 - Issuance of Confidentiality Certificates; single project limitation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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  12. 42 CFR 2a.6 - Issuance of Confidentiality Certificates; single project limitation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Issuance of Confidentiality Certificates; single project limitation. 2a.6 Section 2a.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PROTECTION OF IDENTITY-RESEARCH SUBJECTS § 2a.6 Issuance of...

  13. Genetic polymorphisms in CYP1A1, CYP1B1 and COMT genes in Greenlandic Inuit and Europeans

    PubMed Central

    Ghisari, Mandana; Long, Manhai; Bonefeld-Jørgensen, Eva C.

    2013-01-01

    Background The Indigenous Arctic population is of Asian descent, and their genetic background is different from the Caucasian populations. Relatively little is known about the specific genetic polymorphisms in genes involved in the activation and detoxification mechanisms of environmental contaminants in Inuit and its relation to health risk. The Greenlandic Inuit are highly exposed to legacy persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), and an elucidation of gene–environment interactions in relation to health risks is needed. Objectives The aim of this study was to determine and compare the genotype and allele frequencies of the cytochrome P450 CYP1A1 Ile462Val (rs1048943), CYP1B1 Leu432Val (rs1056836) and catechol-O-methyltransferase COMT Val158Met (rs4680) in Greenlandic Inuit (n=254) and Europeans (n=262) and explore the possible relation between the genotypes and serum levels of POPs. Results The genotype and allele frequency distributions of the three genetic polymorphisms differed significantly between the Inuit and Europeans. For Inuit, the genotype distribution was more similar to those reported for Asian populations. We observed a significant difference in serum polychlorinated biphenyl (CB-153) and the pesticide 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p′-DDE) levels between Inuit and Europeans, and for Inuit also associations between the POP levels and genotypes for CYP1A1, CYP1B1 and COMT. Conclusion Our data provide new information on gene polymorphisms in Greenlandic Inuit that might support evaluation of susceptibility to environmental contaminants and warrant further studies. PMID:23785672

  14. Common genetic variation in CYP1B1 is associated with concentrations of T₄, FT₃ and FT₄ in the sera of polycystic ovary syndrome patients.

    PubMed

    Zou, Shien; Sang, Qing; Wang, Huan; Feng, Ruizhi; Li, Qiaoli; Zhao, Xinzhi; Xing, Qinghe; Jin, Li; He, Lin; Wang, Lei

    2013-04-01

    CYP1B1 encodes an estrogen enzyme that oxidizes 17β-estradiol to 4-hydroxyestradiol. The evidence demonstrates there may be a relationship between CYP1B1 and thyroid function. To date, no study has evaluated if genetic polymorphisms that regulate concentrations of serum FT3 and FT4 contribute to Polycyctic Ovary Syndrome (PCOS). To identify polymorphisms in the CYP1B1 locus associated with PCOS, we genotyped three common polymorphisms across the CYP1B1 locus in 226 patients. A test for association of common variants with susceptibility to PCOS was conducted in a large cohort of 609 subjects. The functional polymorphism CYP1B1 L432V (rs1056836) is associated with serum T4 (P = 0.003), serum FT3 (P < 0.001) and serum FT4 concentrations (P < 0.001). Our study provides the first evidence that genetic variants in CYP1B1 can be associated with serum T4, FT4 and FT3 levels in PCOS. These findings imply novel pathophysiological links between the CYP1B1 locus and thyroid function in PCOS.

  15. Genetic variants of the CYP1B1 gene as predictors of biochemical recurrence after radical prostatectomy in localized prostate cancer patients.

    PubMed

    Gu, Cheng-Yuan; Qin, Xiao-Jian; Qu, Yuan-Yuan; Zhu, Yu; Wan, Fang-Ning; Zhang, Gui-Ming; Sun, Li-Jiang; Zhu, Yao; Ye, Ding-Wei

    2016-07-01

    Clinically localized prostate cancer is curative. Nevertheless many patients suffered from biochemical recurrence (BCR) after radical prostatectomy (RP). Mounting evidence suggest that estrogen and xenobiotic carcinogens play an essential role in progression of prostate cancervia oxidative estrogen metabolism. CYP1B1 is an enzyme involved in the hydroxylation of estrogens, a reaction of key relevance in estrogen metabolism. Given the role of CYP1B1 in the oxidative metabolism of endogenous/exogenous estrogen and compounds, CYP1B1 polymorphisms have the potential to modify its expression and subsequently lead to progression. We hypothesize that genetic variants of the CYP1B1 gene may influence clinical outcome in clinically localized prostate cancer patients. In this cohort study, we genotyped 9 tagging single nucleotide polymorphisms (SNPs) from the CYP1B1 gene in 312 patients treated with RP. For replication, these SNPs were genotyped in an independent cohort of 426 patients. The expression level of CYP1B1 in the adjacent normal prostate tissues was quantified by reverse transcription and real-time polymerase chain reaction. Kaplan-Meier analysis and Cox proportional hazard models were utilized to identify SNPs that correlated with BCR. CYP1B1 rs1056836 was significantly associated with BCR (hazard ratio [HR]: 0.69; 95% confidence interval [CI]: 0.40-0.89, P = 0.002) and relative CYP1B1 mRNA expression. Our findings suggest inherited genetic variation in the CYP1B1 gene may contribute to variable clinical outcomes for patients with clinically localized prostate cancer.

  16. Genetic variants of the CYP1B1 gene as predictors of biochemical recurrence after radical prostatectomy in localized prostate cancer patients

    PubMed Central

    Gu, Cheng-Yuan; Qin, Xiao-Jian; Qu, Yuan-Yuan; Zhu, Yu; Wan, Fang-Ning; Zhang, Gui-Ming; Sun, Li-Jiang; Zhu, Yao; Ye, Ding-Wei

    2016-01-01

    Abstract Clinically localized prostate cancer is curative. Nevertheless many patients suffered from biochemical recurrence (BCR) after radical prostatectomy (RP). Mounting evidence suggest that estrogen and xenobiotic carcinogens play an essential role in progression of prostate cancervia oxidative estrogen metabolism. CYP1B1 is an enzyme involved in the hydroxylation of estrogens, a reaction of key relevance in estrogen metabolism. Given the role of CYP1B1 in the oxidative metabolism of endogenous/exogenous estrogen and compounds, CYP1B1 polymorphisms have the potential to modify its expression and subsequently lead to progression. We hypothesize that genetic variants of the CYP1B1 gene may influence clinical outcome in clinically localized prostate cancer patients. In this cohort study, we genotyped 9 tagging single nucleotide polymorphisms (SNPs) from the CYP1B1 gene in 312 patients treated with RP. For replication, these SNPs were genotyped in an independent cohort of 426 patients. The expression level of CYP1B1 in the adjacent normal prostate tissues was quantified by reverse transcription and real-time polymerase chain reaction. Kaplan–Meier analysis and Cox proportional hazard models were utilized to identify SNPs that correlated with BCR. CYP1B1 rs1056836 was significantly associated with BCR (hazard ratio [HR]: 0.69; 95% confidence interval [CI]: 0.40–0.89, P = 0.002) and relative CYP1B1 mRNA expression. Our findings suggest inherited genetic variation in the CYP1B1 gene may contribute to variable clinical outcomes for patients with clinically localized prostate cancer. PMID:27399092

  17. A new topology of the human Y chromosome haplogroup E1b1 (E-P2) revealed through the use of newly characterized binary polymorphisms.

    PubMed

    Trombetta, Beniamino; Cruciani, Fulvio; Sellitto, Daniele; Scozzari, Rosaria

    2011-01-06

    Haplogroup E1b1, defined by the marker P2, is the most represented human Y chromosome haplogroup in Africa. A phylogenetic tree showing the internal structure of this haplogroup was published in 2008. A high degree of internal diversity characterizes this haplogroup, as well as the presence of a set of chromosomes undefined on the basis of a derived character. Here we make an effort to update the phylogeny of this highly diverse haplogroup by including seven mutations which have been newly discovered by direct resequencing. We also try to incorporate five previously-described markers which were not, however, reported in the 2008 tree. Additionally, during the process of mapping, we found that two previously reported SNPs required a new position on the tree. There are three key changes compared to the 2008 phylogeny. Firstly, haplogroup E-M2 (former E1b1a) and haplogroup E-M329 (former E1b1c) are now united by the mutations V38 and V100, reducing the number of E1b1 basal branches to two. The new topology of the tree has important implications concerning the origin of haplogroup E1b1. Secondly, within E1b1b1 (E-M35), two haplogroups (E-V68 and E-V257) show similar phylogenetic and geographic structure, pointing to a genetic bridge between southern European and northern African Y chromosomes. Thirdly, most of the E1b1b1* (E-M35*) paragroup chromosomes are now marked by defining mutations, thus increasing the discriminative power of the haplogroup for use in human evolution and forensics.

  18. Skatole (3-Methylindole) Is a Partial Aryl Hydrocarbon Receptor Agonist and Induces CYP1A1/2 and CYP1B1 Expression in Primary Human Hepatocytes

    PubMed Central

    Balaguer, Patrick; Ekstrand, Bo; Daujat-Chavanieu, Martine; Gerbal-Chaloin, Sabine

    2016-01-01

    Skatole (3-methylindole) is a product of bacterial fermentation of tryptophan in the intestine. A significant amount of skatole can also be inhaled during cigarette smoking. Skatole is a pulmonary toxin that induces the expression of aryl hydrocarbon receptor (AhR) regulated genes, such as cytochrome P450 1A1 (CYP1A1), in human bronchial cells. The liver has a high metabolic capacity for skatole and is the first organ encountered by the absorbed skatole; however, the effect of skatole in the liver is unknown. Therefore, we investigated the impact of skatole on hepatic AhR activity and AhR-regulated gene expression. Using reporter gene assays, we showed that skatole activates AhR and that this is accompanied by an increase of CYP1A1, CYP1A2 and CYP1B1 expression in HepG2-C3 and primary human hepatocytes. Specific AhR antagonists and siRNA-mediated AhR silencing demonstrated that skatole-induced CYP1A1 expression is dependent on AhR activation. The effect of skatole was reduced by blocking intrinsic cytochrome P450 activity and indole-3-carbinole, a known skatole metabolite, was a more potent inducer than skatole. Finally, skatole could reduce TCDD-induced CYP1A1 expression, suggesting that skatole is a partial AhR agonist. In conclusion, our findings suggest that skatole and its metabolites affect liver homeostasis by modulating the AhR pathway. PMID:27138278

  19. Cytochrome P450 1B1, a new keystone in gene-environment interactions related to human head and neck cancer?

    PubMed

    Thier, Ricarda; Brüning, Thomas; Roos, Peter H; Bolt, Hermann M

    2002-06-01

    Alcohol consumption and tobacco smoking are major causes of head and neck cancers, and regional differences point to the importance of research into gene-environment interactions. Much interest has been focused on polymorphisms of CYP1A1 and of GSTM1 and GSTT1, but a number of studies have not demonstrated significant effects. This has mostly been ascribed to small sample sizes. In general, the impact of polymorphisms of metabolic enzymes appears inconsistent, with some reports of weak-to-moderate associations, and with others of no elevation of risks. The classical cytochrome P450 isoenzyme considered for metabolic activation of polycyclic aromatic hydrocarbons (PAH) is CYP1A1. A new member of the CYP1 family, CYP1B1, was cloned in 1994, currently representing the only member of the CYP1B subfamily. A number of single nucleotide polymorphisms of the CYP1B1 gene have been reported. The amino acid substitutions Val432Leu ( CYP1B1*3) and Asn453Ser ( CYP1B1*4), located in the heme binding domain of CYP1B1, appear as likely candidates to be linked with biological effects. CYP1B1 activates a wide range of PAH, aromatic and heterocyclic amines. Very recently, the CYP1B1 codon 432 polymorphism ( CYP1B1*3) has been identified as a susceptibility factor in smoking-related head-and-neck squamous cell cancer. The impact of this polymorphic variant of CYP1B1 on cancer risk was also reflected by an association with the frequency of somatic mutations of the p53 gene. Combined genotype analysis of CYP1B1 and the glutathione transferases GSTM1 or GSTT1 has pointed to interactive effects. This provides new molecular evidence that tobacco smoke-specific compounds relevant to head and neck carcinogenesis are metabolically activated through CYP1B1 and is consistent with a major pathogenetic relevance of PAH as ingredients of tobacco smoke.

  20. The role of cytochrome P450 1B1 and its associated mid-chain hydroxyeicosatetraenoic acid metabolites in the development of cardiac hypertrophy induced by isoproterenol.

    PubMed

    Maayah, Zaid H; Althurwi, Hassan N; El-Sherbeni, Ahmed A; Abdelhamid, Ghada; Siraki, Arno G; El-Kadi, Ayman O S

    2017-03-01

    Numerous experimental studies have demonstrated the role of cytochrome P450 1B1 (CYP1B1) and its associated mid-chain hydroxyeicosatetraenoic acids (mid-chain HETEs) metabolite in the pathogenesis of cardiac hypertrophy. However, the ability of isoproterenol (ISO) to induce cardiac hypertrophy through mid-chain HETEs has not been investigated yet. Therefore, we hypothesized that ISO induces cardiac hypertrophy through the induction of CYP1B1 and its associated mid-chain HETE metabolites. To test our hypothesis, Sprague-Dawley rats were treated with ISO (5 mg/kg i.p.) for 12 and 72 h whereas, human ventricular cardiomyocytes RL-14 cells were exposed to 100 μM ISO in the presence and absence of 0.5 μM tetramethoxystilbene (TMS) a selective CYP1B1 inhibitor, or 25 nM CYP1B1-siRNA. Moreover, RL-14 cells were transiently transfected with the CRISPR-CYP1B1 plasmid. Thereafter, real-time PCR, western blot analysis, and liquid chromatography-electrospray ionization mass spectroscopy were used to determine the level of gene expression, protein expression, and mid-chain HETEs, respectively. Our results showed that ISO induced CYP1B1 protein expression and the level of cardiac mid-chain HETEs in vivo at pre-hypertrophic and hypertrophic stage. In vitro, inhibition of CYP1B1 using TMS or CYP1B1-siRNA significantly attenuates ISO-induced hypertrophy. Furthermore, overexpression of CYP1B1 significantly induced cellular hypertrophy and mid-chain HETEs metabolite. Mechanistically, the protective effect of TMS against cardiac hypertrophy was mediated through the modulation of superoxide anion, mitogen-activated protein kinases (MAPKs), and nuclear factor-κB (NF-κB). In conclusion, our study provides the first evidence that CYP1B1 and its associated mid-chain HETE metabolites are directly involved in the ISO-induced cardiac hypertrophy.

  1. Monitoring of aflatoxin G1, B1, G2, and B2 occurrence in some samples of walnut.

    PubMed

    Habibipour, Reza; Tamandegani, Parisa Rahimi; Farmany, Abbas

    2016-12-01

    This research was conducted to monitor the aflatoxigenic fungi and aflatoxin contamination of walnut in the Hamedan province. For this purpose, 40 samples were analyzed. Aspergillus, Alternaria, Rhizopus, Cladosporium, Fusarium, yeast, and some different bacteria were isolated from walnuts. Aspergillus is the most frequent genus. Aspergillus flavus was predominantly isolated. HPLC was used for evaluation of aflatoxin contamination of walnut samples. Aflatoxins G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates. AFG1 and AFB1 were being predominant at concentration ranges of 1.7-18.2 and 0-8.2 ngg(-1), respectively. Highest levels were found in one sample that was highly contaminated with Aspergillus flavus/Aspergillus parasiticus. Methyl beta cyclodextrin also was performed for detection of aflatoxigenic Aspergillus isolates. The results showed that only 31.6% (p < 0.05) of A. flavus and A. parasiticus isolates were able to produce aflatoxin. A significant difference was shown between shielded and unshielded walnut in aflatoxin contamination. The content of aflatoxin in most of the walnut samples did not reach to maximum tolerable limit for aflatoxin B1 in EU standard (p > 0.05). Thus, systematic and continues monitoring of walnuts is recommended.

  2. Cytochrome P450 1B1 Val432Leu polymorphism and breast cancer risk in Nigerian women: a case control study

    PubMed Central

    Okobia, Michael N; Bunker, Clareann H; Garte, Seymour J; Zmuda, Joseph M; Ezeome, Emmanuel R; Anyanwu, Stanley NC; Uche, Emmanuel EO; Osime, Usifo; Ojukwu, Joseph; Kuller, Lewis H; Ferrell, Robert E; Taioli, Emanuela

    2009-01-01

    Background Cytochrome P450 1B1 (CYP1B1) is active in the metabolism of estrogens to reactive catechols and of different procarcinogens. Several studies have investigated the relationship between genetic polymorphisms of CYP1B1 and breast cancer risk with inconsistent results. A G → C transversion polymorphism in the heme-binding region in codon 432 of the gene results in amino acid change (Val → Leu); the Leu allele display increased catalytic efficiency for 4-hydroxylation of estradiol in some experimental systems. Methods In this study, we utilized a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay to assess the relationship between this polymorphism and breast cancer risk in a case control study including 250 women with breast cancer and 250 controls from four University Teaching Hospitals in Southern Nigeria. Results Heterozygosity for the CYP1B1 M1 genotype (CYP1B1 M1 [Val/Leu]) was associated with a significant 59% increased risk of breast cancer (OR = 1.59, 95% CI 1.01–2.58) while homozygosity for the genotype (CYP1B1 M1 [Leu/Leu]) conferred a non-significant 51% increased risk of breast cancer. These risk profiles were modified in subgroup analysis. In premenopausal women, harboring at least one CYP1B1 (Leu) allele conferred a significant two-fold increased risk of breast cancer (OR = 2.04, 95% CI 1.10–3.78). No significant association was observed in postmenopausal women (OR = 1.08, 95% CI 0.57–2.04). Conclusion Our results suggest that the codon 432 polymorphism of the CYP1B1 gene is associated with increased risk of breast cancer and is particularly involved in breast cancer risk in premenopausal women of African descent. PMID:19208203

  3. Association of polymorphisms and haplotypes in the cytochrome P450 1B1 gene with uterine leiomyoma: A case control study

    PubMed Central

    SALIMI, SAEEDEH; KHODAMIAN, MARYAM; NAROOIE-NEJAD, MEHRNAZ; HAJIZADEH, AZAM; FAZELI, KIMIA; NAMAZI, LIDA; YAGHMAEI, MINOO

    2015-01-01

    Uterine leiomyoma (UL) is an estrogen-dependent neoplasm of the uterus and estrogen metabolizing enzymes affect its promotion and progression. The aim of the present study was to evaluate the association between four single-nucleotide polymorphisms (SNPs) of the cytochrome P450 1B1 (CYP1B1) gene and UL risk. Four SNPs of the CYP1B1 gene in 105 UL patients and 112 unrelated healthy controls were genotyped using a direct sequencing method. Haplotype analyses were performed with UNPHASED software and linkage disequilibrium (LD) was assessed by Haploview software. There were no associations between Leu432Val (rs1056836), Asp449Asp (rs1056837) and Asn453Ser (rs1800440) polymorphisms of the CYP1B1 gene and UL. Although the genotypic frequencies of the Arg368His (rs79204362) polymorphism did not differ between the two groups, the frequency of A (His) allele was significantly higher in UL females (P=0.02). In addition, the frequency of GTAA haplotype was significantly higher in the controls and played a protective role in UL susceptibility. A strong LD between the three common SNPs (rs1056836, rs1056837 and rs1800440) in the CYP1B1 gene was observed in the population. In conclusion, a higher frequency of the CYP1B1 368His (A) allele was observed in UL females. The frequency of the GTAA haplotype was significantly higher in healthy females and this haplotype played a protective role in UL susceptibility. PMID:26075073

  4. No association of genetic polymorphisms in CYP1B1 with primary open-angle glaucoma: a meta- and gene-based analysis

    PubMed Central

    Dong, Shuqian; Yang, Jingyun; Yu, Weihong; Kota, Pravina; Xia, Xiaobo

    2012-01-01

    Purpose To examine the effects of genetic polymorphisms in cytochrome P450, subfamily 1, polypeptide 1 (C1P1B1) on primary open-angle glaucoma (POAG). Methods A systematic literature search was performed, and random-effects meta-analyses were used to evaluate genetic polymorphisms in CYP1B1 with POAG. A gene-based analysis was conducted to investigate the cumulative effects of genetic polymorphisms in CYP1B1. Results A total of six studies from published papers were included in our analysis. Random-effects meta-analyses failed to detect any significant association of POAG with genetic polymorphisms in CYP1B1, including rs180040, rs1056836, rs10012, rs1056827, rs1056837, and rs2567206. The gene-based analysis indicated that the cumulative effect of genetic polymorphisms in CYP1B1 is not associated with POAG (p>0.50). Conclusions We did not find any evidence of strong association of POAG with CYP1B1 genetic polymorphisms and their cumulative effect. PMID:22509109

  5. Association of polymorphisms and haplotypes in the cytochrome P450 1B1 gene with uterine leiomyoma: A case control study.

    PubMed

    Salimi, Saeedeh; Khodamian, Maryam; Narooie-Nejad, Mehrnaz; Hajizadeh, Azam; Fazeli, Kimia; Namazi, Lida; Yaghmaei, Minoo

    2015-03-01

    Uterine leiomyoma (UL) is an estrogen-dependent neoplasm of the uterus and estrogen metabolizing enzymes affect its promotion and progression. The aim of the present study was to evaluate the association between four single-nucleotide polymorphisms (SNPs) of the cytochrome P450 1B1 (CYP1B1) gene and UL risk. Four SNPs of the CYP1B1 gene in 105 UL patients and 112 unrelated healthy controls were genotyped using a direct sequencing method. Haplotype analyses were performed with UNPHASED software and linkage disequilibrium (LD) was assessed by Haploview software. There were no associations between Leu432Val (rs1056836), Asp449Asp (rs1056837) and Asn453Ser (rs1800440) polymorphisms of the CYP1B1 gene and UL. Although the genotypic frequencies of the Arg368His (rs79204362) polymorphism did not differ between the two groups, the frequency of A (His) allele was significantly higher in UL females (P=0.02). In addition, the frequency of GTAA haplotype was significantly higher in the controls and played a protective role in UL susceptibility. A strong LD between the three common SNPs (rs1056836, rs1056837 and rs1800440) in the CYP1B1 gene was observed in the population. In conclusion, a higher frequency of the CYP1B1 368His (A) allele was observed in UL females. The frequency of the GTAA haplotype was significantly higher in healthy females and this haplotype played a protective role in UL susceptibility.

  6. Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

    SciTech Connect

    Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong; Khanal, Tilak; Choi, Jae Ho; Chung, Young Chul; Jeong, Tae Cheon; Jeong, Hye Gwang

    2014-10-01

    Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 and CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO expression.

  7. Effects of pomegranate chemical constituents/intestinal microbial metabolites on CYP1B1 in 22Rv1 prostate cancer cells.

    PubMed

    Kasimsetty, Sashi G; Bialonska, Dobroslawa; Reddy, Muntha K; Thornton, Cammi; Willett, Kristine L; Ferreira, Daneel

    2009-11-25

    The cytochrome P450 enzyme, CYP1B1, is an established target in prostate cancer chemoprevention. Compounds inhibiting CYP1B1 activity are contemplated to exert beneficial effects at three stages of prostate cancer development, that is, initiation, progression, and development of drug resistance. Pomegranate ellagitannins/microbial metabolites were examined for their CYP1B1 inhibitory activity in a recombinant CYP1B1-mediated ethoxyresorufin-O-deethylase (EROD) assay. Urolithin A, a microbial metabolite, was the most potent uncompetitive inhibitor of CYP1B1-mediated EROD activity, exhibiting 2-fold selectivity over CYP1A1, while urolithin B was a noncompetitive inhibitor with 3-fold selectivity. The punicalins and punicalagins exhibited potent CYP1A1 inhibition with 5-10-fold selectivity over CYP1B1. Urolithins, punicalins, and punicalagins were tested for their 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced CYP1 inhibitory activity in the 22Rv1 prostate cancer cell line. Urolithins A and B showed a decrease in their CYP1-mediated EROD inhibitory IC50 values upon increasing their treatment times from 30 min to 24 h. Urolithin C, 8-O-methylurolithin A, and 8,9-di-O-methylurolithin C caused a potent CYP1-mediated EROD inhibition in 22Rv1 cells upon 24 h of incubation. Neutral red uptake assay results indicated that urolithin C, 8-O-methylurolithin A, and 8,9-di-O-methylurolithin C induced profound cytotoxicity in the proximity of their CYP1 inhibitory IC50 values. Urolithins A and B were studied for their cellular uptake and inhibition of TCDD-induced CYP1B1 expression. Cellular uptake experiments demonstrated a 5-fold increase in urolithin uptake by 22Rv1 cells. Western blots of the CYP1B1 protein indicated that the urolithins interfered with the expression of CYP1B1 protein. Thus, urolithins were found to display a dual mode mechanism by decreasing CYP1B1 activity and expression.

  8. Screening of the LTBP2 gene in 214 Chinese sporadic CYP1B1-negative patients with primary congenital glaucoma

    PubMed Central

    Chen, Xueli; Chen, Yuhong; Fan, Bao Jian; Xia, Mingying; Wang, Li

    2016-01-01

    Purpose To identify deleterious mutations in the latent transforming growth factor-β–binding protein 2 (LTBP2) gene in sporadic patients with primary congenital glaucoma (PCG) from a Han Chinese population, which had been excluded for mutations in the CYP1B1 gene. Methods In this retrospective case–control study, 36 coding exons and adjacent exon–intron boundaries of LTBP2 were amplified with PCR and screened for mutations with Sanger sequencing in DNA samples of 214 sporadic patients with PCG. Sequence variants identified in the patients with PCG were subsequently screened in 100 unaffected control subjects and the unaffected parents of the patients with PCG who had sequence changes in LTBP2. Results Eight heterozygous single nucleotide polymorphisms (SNPs) in coding regions of LTBP2 were identified in the patients with PCG. Four of these SNPs were missense changes that resulted in the replacement of amino acids (rs2304707, rs116914994, rs45468895, and rs763035721), two of which (rs2304707 and rs116914994) were also present in the control subjects. No significant differences in the frequencies of the missense SNPs were found between the patients with PCG and the controls. The two missense SNPs, rs45468895 and rs763035721, which were each found in one patient also existed in their unaffected parents, suggesting that these two SNPs were not segregated in these families and are unlikely to be a disease-causative variant. In addition, four synonymous SNPs were detected in the patients with PCG (rs61738025, rs862031, rs199805158, and rs12586758). Conclusions The results showed that no deleterious mutations were found in coding regions of LTBP2 in patients with PCG, suggesting that it is not a causal gene for PCG in the Han Chinese population. PMID:27293371

  9. The enhanced atorvastatin hepatotoxicity in diabetic rats was partly attributed to the upregulated hepatic Cyp3a and SLCO1B1

    PubMed Central

    Shu, Nan; Hu, Mengyue; Ling, Zhaoli; Liu, Peihua; Wang, Fan; Xu, Ping; Zhong, Zeyu; Sun, Binbin; Zhang, Mian; Li, Feng; Xie, Qiushi; Liu, Xiaodong; Liu, Li

    2016-01-01

    Liver injury is a common adverse effect of atorvastatin. This study aimed to investigate atorvastatin-induced hepatotoxicity in diabetic rats induced by high-fat diet combined with streptozotocin. The results showed that 40 mg/kg atorvastatin was lethal to diabetic rats, whose mean survival time was 6.2 days. Severe liver injury also occurred in diabetic rats treated with 10 mg/kg and 20 mg/kg atorvastatin. The in vitro results indicated that atorvastatin cytotoxicity in hepatocytes of diabetic rats was more severe than normal and high-fat diet feeding rats. Expressions and activities of hepatic Cyp3a and SLCO1B1 were increased in diabetic rats, which were highly correlated with hepatotoxicity. Antioxidants (glutathione and N-Acetylcysteine), Cyp3a inhibitor ketoconazole and SLCO1B1 inhibitor gemfibrozil suppressed cytotoxicity and ROS formation in primary hepatocytes of diabetic rats. In HepG2 cells, up-regulations of CYP3A4 and SLCO1B1 potentiated hepatotoxicity and ROS generation, whereas knockdowns of CYP3A4 and SLCO1B1 as well as CYP3A4/SLCO1B1 inhibitions showed the opposite effects. Phenobarbital pretreatment was used to induce hepatic Cyp3a and SLCO1B1 in rats. Phenobarbital aggravated atorvastatin-induced hepatotoxicity, while decreased plasma exposure of atorvastatin. All these findings demonstrated that the upregulations of hepatic Cyp3a and SLCO1B1 in diabetic rats potentiated atorvastatin-induced hepatotoxicity via increasing ROS formation. PMID:27624558

  10. The effect of organic anion-transporting polypeptides 1B1, 1B3 and 2B1 on the antitumor activity of flavopiridol in breast cancer cells.

    PubMed

    Brenner, Stefan; Riha, Juliane; Giessrigl, Benedikt; Thalhammer, Theresia; Grusch, Michael; Krupitza, Georg; Stieger, Bruno; Jäger, Walter

    2015-01-01

    The contribution of organic anion transporting polypeptides (OATPs) to the cellular uptake of flavopiridol was investigated in OATP1B1-, OATP1B3- and OATP2B1-expressing Chinese hamster ovary (CHO) cells. Uptake of flavopiridol into these cells showed typical Michaelis-Menten kinetics with much higher transport capacity for OATP1B3 compared to OATP1B1 and OATP2B1 (Vmax/Km, 33.9 vs. 8.84 and 2.41 µl/mg/min, respectively). The predominant role of OATPs was further supported by a dramatic inhibition of flavopiridol uptake in the presence of the OATP substrate rifampicin. Uptake of flavopiridol by OATPs also seems to be an important determinant in breast cancer cells. The much higher mRNA level for OATP1B1 found in wild-type compared to ZR-75-1 OATP1B1 knockdown cells correlated with higher flavopiridol initial uptake leading to 4.6-fold decreased IC50 values in the cytotoxicity assay (IC50, 1.45 vs. 6.64 µM). Cell cycle profile also showed a clear incidence for a stronger cell cycle arrest in the G2/M phase for ZR-75-1 wild-type cells compared to OATP1B1 knockdown cells, further indicating an active uptake via OATP1B1. In conclusion, our results revealed OATP1B1, OATP1B3 and OATP2B1 as uptake transporters for flavopiridol in cancer cells, which may also apply in patients during cancer therapy.

  11. Association of CYP1B1 gene polymorphisms and the positive expression of estrogen alpha and estrogen beta with endometrial cancer risk.

    PubMed

    Zhu, Z Y; Mu, Y Q; Fu, X M; Li, S M; Zhao, F X

    2011-01-01

    To investigate the relationship between the CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and the incidence of endometrial cancer. The relationship between CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and endometrial cancer was investigated using the allele-specific polymerase chain reaction method to analyze gene polymorphism in exon 3 codon 432 (C-G) of CYP1B1. Our results are as follows: in endometrial cancer cases the prevalence rates of CYP1B1 L432V genotypes C/C, C/G, and G/G were 47.2%, 36.1%, and 16.7%, respectively, and 68.8%, 23.8% and 7.5% in the control group, respectively. The frequencies of CYP1B1 C and G alleles were 65.3% and 34.7% in endometrial cancer patients and 80.6% and 19.4% in the control group. A significant difference was found in the genotype distributions or allele frequencies of CYP1B1 L432V polymorphism between the two groups (p < 0.05). Compared with wild-type C/C, the susceptibility of endometrial cancer with homozygotic mutation G/G and heterozygotic mutation C/G increased by 3.235 (95%CI 1.111-9.425) and 2.214 (95% CI 1.067-4.593). Moveover, the positive expression of ERalpha in genotypes G/G and C/G was higher than in the wild genotype C/C (p < 0.05). In conclusion, allelic polymorphism of CYP1B1 L432V increases the risk of endometrial cancer and has a positive correlation with ERalpha expression.

  12. Characterization of 5-HT receptors mediating constriction of porcine carotid arteriovenous anastomoses; involvement of 5-HT1B/1D and novel receptors

    PubMed Central

    De Vries, Peter; Villalón, Carlos M; Heiligers, Jan P C; Saxena, Pramod R

    1998-01-01

    It was previously shown that porcine cranial arteriovenous anastomoses (AVAs) constrict to 5-hydroxytryptamine (5-HT), ergotamine, dihydroergotamine, as well as sumatriptan and that sumatriptan acts exclusively via 5-HT1B/1D receptors. The present study was devoted to establish the contribution of 5-HT1B/1D receptors in the constriction of AVAs elicited by 5-HT (in presence of 0.5 mg kg−1 ketanserin), ergotamine and dihydroergotamine in anaesthetized pigs.Intracarotid infusion of 5-HT (2 μg kg−1 min−1) and intravenous doses of ergotamine (2.5–20 μg kg−1) and dihydroergotamine (3–100 μg kg−1) reduced AVA and increased nutrient blood flows and vascular conductances. The vasodilator response to 5-HT, observed mainly in the skin and ear, was much more prominent than that of the ergot alkaloids.Treatment with the 5-HT1B/1D receptor antagonist GR127935 (0.5 mg kg−1, i.v.) significantly attenuated both ergot-induced AVA constriction and arteriolar dilatation, whereas GR127935 only slightly affected the carotid vascular effects of 5-HT.The results suggest that 5-HT constricts carotid AVAs primarily via receptors, which seem to differ from those (5-HT1B/1D) stimulated by sumatriptan. The ergot alkaloids produce AVA constriction for a substantial part via 5-HT1B/1D receptors, but also stimulate unidentified receptors. Both these non-5-HT1B/1D receptors may be targets for the development of novel antimigraine drugs.The moderate vasodilator response to the ergot derivatives seems to be mediated, at least in part, by 5-HT1B/1D receptors, whereas the arteriolar dilatation caused by 5-HT may be mediated by other, possibly 5-HT7 receptors. PMID:9605562

  13. ANGIOTENSIN II-INDUCED VASCULAR SMOOTH MUSCLE CELL MIGRATION AND GROWTH ARE MEDIATED BY CYTOCHROME P450 1B1-DEPENDENT SUPEROXIDE GENERATION

    PubMed Central

    Yaghini, Fariborz A.; Song, Chi Young; Lavrentyev, Eduard N.; Ghafoor, Hafiz U. B.; Fang, Xiao R.; Estes, Anne M.; Campbell, William B.; Malik, Kafait U.

    2010-01-01

    Cytochrome P450 1B1, expressed in vascular smooth muscle cells, can metabolize arachidonic acid in vitro into several products including 12- and 20-hydroxyeicosatetraenoic acids that stimulate vascular smooth muscle cell growth. This study was conducted to determine if cytochrome P450 1B1 contributes to angiotensin II-induced rat aortic smooth muscle cell migration, proliferation and protein synthesis. Ang II stimulated migration of these cells, measured by the wound healing approach, by 1.78 fold and DNA synthesis, measured by [3H]thymidine incorporation, by 1.44 fold after 24 hours, and protein synthesis, measured by [3H]leucine incorporation, by 1.40 fold after 48 hours. Treatment of vascular smooth muscle cells with the cytochrome P450 1B1 inhibitor, 2, 4, 3′, 5′-tetramethoxystilbene, or transduction of these cells with adenovirus cytochrome P450 1B1 shRNA, but not its scrambled control, reduced the activity of this enzyme and abolished angiotensin II- and arachidonic acid-induced cell migration, [3H]thymidine and [3H]leucine incorporation. Metabolism of arachidonic acid to 5-, 12-, 15- and 20-hydoxyeicosatetraenoic acids in these cells was not altered, but angiotensin II- and arachidonic acid-induced reactive oxygen species production and extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase, activity were inhibited by 2, 4, 3′, 5′-tetramethoxystilbene and cytochrome P450 1B1 shRNA, and by tempol that inactivates reactive oxygen species. Tempol did not alter cytochrome P450 1B1 activity. These data suggest that angiotensin II-induced vascular smooth muscle cell migration and growth are mediated by reactive oxygen species generated from arachidonic acid by cytochrome P450 1B1 and activation of extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase. PMID:20439821

  14. Cytochrome P450 1B1 gene disruption minimizes deoxycorticosterone acetate-salt-induced hypertension and associated cardiac dysfunction and renal damage in mice.

    PubMed

    Jennings, Brett L; Estes, Anne M; Anderson, Larry J; Fang, Xiao R; Yaghini, Fariborz A; Fan, Zheng; Gonzalez, Frank J; Campbell, William B; Malik, Kafait U

    2012-12-01

    Previously, we showed that the cytochrome P450 1B1 inhibitor 2,3',4,5'-tetramethoxystilbene reversed deoxycorticosterone acetate (DOCA)-salt-induced hypertension and minimized endothelial and renal dysfunction in the rat. This study was conducted to test the hypothesis that cytochrome P450 1B1 contributes to cardiac dysfunction, and renal damage and inflammation associated with DOCA-salt-induced hypertension, via increased production of reactive oxygen species and modulation of neurohumoral factors and signaling molecules. DOCA-salt increased systolic blood pressure, cardiac and renal cytochrome P450 1B1 activity, and plasma levels of catecholamines, vasopressin, and endothelin-1 in wild-type (Cyp1b1(+/+)) mice that were minimized in Cyp1b1(-/-) mice. Cardiac function, assessed by echocardiography, showed that DOCA-salt increased the thickness of the left ventricular posterior and anterior walls during diastole, the left ventricular internal diameter, and end-diastolic and end-systolic volume in Cyp1b1(+/+) but not in Cyp1b1(-/-) mice; stroke volume was not altered in either genotype. DOCA-salt increased renal vascular resistance and caused vascular hypertrophy and renal fibrosis, increased renal infiltration of macrophages and T lymphocytes, caused proteinuria, increased cardiac and renal nicotinamide adenine dinucleotide phosphate-oxidase activity, caused production of reactive oxygen species, and increased activities of extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, and cellular-Src; these were all reduced in DOCA-salt-treated Cyp1b1(-/-) mice. Renal and cardiac levels of eicosanoids were not altered in either genotype of mice. These data suggest that, in DOCA-salt hypertension in mice, cytochrome P450 1B1 plays a pivotal role in cardiovascular dysfunction, renal damage, and inflammation, and increased levels of catecholamines, vasopressin, and endothelin-1, consequent to generation of reactive oxygen species and activation of

  15. CYP1A1 and CYP1B1 genetic polymorphisms, smoking and breast cancer risk in a Finnish Caucasian population.

    PubMed

    Sillanpää, Pia; Heikinheimo, Liisa; Kataja, Vesa; Eskelinen, Matti; Kosma, Veli-Matti; Uusitupa, Matti; Vainio, Harri; Metsola, Katja; Hirvonen, Ari

    2007-09-01

    We investigated the associations between two CYP1A1 polymorphisms (Ile462Val and Thr461Asn) and one CYP1B1 polymorphism (Leu432Val) and breast cancer risk. The study population consisted of 483 breast cancer patients and 482 healthy population controls, all of homogenous Finnish origin. No statistically significant overall associations were found between the CYP1A1 and CYP1B1 genotypes and breast cancer risk. However, a significant increase in the breast cancer risk was seen for women who had smoked 1-9 cigarettes/day and carried the CYP1B1 432Val allele; the OR was 2.6 (95% CI 1.07-6.46) for women carrying the Leu/Val genotype and 5.1 (95% CI 1.30-19.89, P for trend 0.005) for women with the Val/Val genotype compared to similarly smoking women homozygous for the 432Leu allele. Furthermore, when CYP1B1 genotypes were combined with the previously analyzed N-acetyl transferase (NAT2) genotypes, a significant increase in breast cancer risk was found among women who had at least one CYP1B1 432Val allele together with the NAT2 slow acetylator genotype (OR 1.52; 95% CI 1.03-2.24) compared to women carrying a combination of CYP1B1 Leu/Leu and NAT2 rapid acetylator genotypes. This risk was seen to be confined to ever smokers; the OR was 2.46 (95% CI 1.11-5.45) for ever smokers carrying at least one CYP1B1 432Val allele together with the NAT2 slow acetylator genotype compared to ever smokers with the CYP1B1 Leu/Leu and NAT2 rapid acetylator genotype combination. Our results suggest that the CYP1B1 polymorphism may be an important modifier of breast cancer risk in Finnish Caucasian women who have been exposed to tobacco smoke and/or carry the NAT2 slow acetylator genotype.

  16. Mapping SLCO1B1 Genetic Variation for Global Precision Medicine in Understudied Regions in Africa: A Focus on Zulu and Cape Admixed Populations.

    PubMed

    Hoosain, Nisreen; Pearce, Brendon; Jacobs, Clifford; Benjeddou, Mongi

    2016-09-01

    The U.S. President Barack Obama has announced, in his State of the Union address on January 20, 2015, the Precision Medicine Initiative, a US$215-million program. For global precision medicine to become a reality, however, biological and environmental "variome" in previously understudied populations ought to be mapped and catalogued. Chief among the molecular targets that warrant global mapping is the organic anion-transporting polypeptide 1B1 (OATP1B1), encoded by solute carrier organic anion transporter family member 1B1 (SLCO1B1), a hepatic uptake transporter predominantly expressed in the basolateral side of hepatocytes. Human OATP1B1 plays a crucial role in the transport of a wide variety of substrates. This includes endogenous compounds such as bile salts as well as medicines, including benzylpenicillin, methotrexate, pravastatin, and rifampicin, and natural toxins microcystin and phalloidin. Genetic variations observed in the SLCO1B1 gene have been associated with altered in vitro and in vivo OATP1B1 transport activity, and consequently influencing patients' response to medicines, toxins, and susceptibility to common complex diseases. Well-characterized haplotypes, *5 (RS4149056C) and *15 (RS4149056T), have been associated with a strikingly reduced uptake of multiple OATP1B1 substrates, including estrone-3-sulfate, estradiol-17β-d-glucuronide, atorvastatin, cerivastatin, pravastatin, and rifampicin. In particular, RS4149056C is observed in 60% of the Cape admixed (CA) population and is associated with increased plasma concentrations of many statins as well as fexofenadine and repaglinide. We designed and optimized a SNaPshot minisequencing panel to characterize the variants of relevance for precision medicine in the clinic. We report here the first study on allele and genotype frequencies for 10 nonsynonymous, 4 synonymous, and 6 intronic single-nucleotide polymorphisms of SLCO1B1 in the Zulu and CA populations of South Africa. These variants are further

  17. Disruption of the cytochrome P-450 1B1 gene exacerbates renal dysfunction and damage associated with angiotensin II-induced hypertension in female mice.

    PubMed

    Jennings, Brett L; Moore, Joseph A; Pingili, Ajeeth K; Estes, Anne M; Fang, Xiao R; Kanu, Alie; Gonzalez, Frank J; Malik, Kafait U

    2015-05-01

    Recently, we demonstrated in female mice that protection against ANG II-induced hypertension and associated cardiovascular changes depend on cytochrome P-450 (CYP)1B1. The present study was conducted to determine if Cyp1b1 gene disruption ameliorates renal dysfunction and organ damage associated with ANG II-induced hypertension in female mice. ANG II (700 ng·kg(-1)·min(-1)) infused by miniosmotic pumps for 2 wk in female Cyp1b1(+/+) mice did not alter water consumption, urine output, Na(+) excretion, osmolality, or protein excretion. However, in Cyp1b1(-/-) mice, ANG II infusion significantly increased (P < 0.05) water intake (5.50 ± 0.42 ml/24 h with vehicle vs. 8.80 ± 0.60 ml/24 h with ANG II), urine output (1.44 ± 0.37 ml/24 h with vehicle vs. 4.30 ± 0.37 ml/24 h with ANG II), and urinary Na(+) excretion (0.031 ± 0.016 mmol/24 h with vehicle vs. 0.099 ± 0.010 mmol/24 h with ANG II), decreased osmolality (2,630 ± 79 mosM/kg with vehicle vs. 1,280 ± 205 mosM/kg with ANG II), and caused proteinuria (2.60 ± 0.30 mg/24 h with vehicle vs. 6.96 ± 0.55 mg/24 h with ANG II). Infusion of ANG II caused renal fibrosis, as indicated by an accumulation of renal interstitial α-smooth muscle actin, collagen, and transforming growth factor-β in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. ANG II also increased renal production of ROS and urinary excretion of thiobarburic acid-reactive substances and reduced the activity of antioxidants and urinary excretion of nitrite/nitrate and the 17β-estradiol metabolite 2-methoxyestradiol in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. These data suggest that Cyp1b1 plays a critical role in female mice in protecting against renal dysfunction and end-organ damage associated with ANG II-induced hypertension, in preventing oxidative stress, and in increasing activity of antioxidant systems, most likely via generation of 2-methoxyestradiol from 17β-estradiol.

  18. Haemocoel injection of PirA1B1 to Galleria mellonella larvae leads to disruption of the haemocyte immune functions.

    PubMed

    Wu, Gongqing; Yi, Yunhong

    2016-10-13

    The bacterium Photorhabdus luminescens produces a number of insecticidal proteins to kill its larval prey. In this study, we cloned the gene coding for a binary toxin PirA1B1 and purified the recombinant protein using affinity chromatography combined with desalination technology. Furthermore, the cytotoxicity of the recombinant protein against the haemocytes of Galleria mellonella larvae was investigated. We found that the protein had haemocoel insecticidal activity against G. mellonella with an LD50 of 131.5 ng/larva. Intrahaemocoelic injection of PirA1B1 into G. mellonella resulted in significant decreases in haemocyte number and phagocytic ability. In in vitro experiments, PirA1B1 inhibited the spreading behaviour of the haemocytes of G. mellonella larvae and even caused haemocyte degeneration. Fluorescence microscope analysis and visualization of haemocyte F-actin stained with phalloidin-FITC showed that the PirA1B1 toxin disrupted the organization of the haemocyte cytoskeleton. Our results demonstrated that the PirA1B1 toxin disarmed the insect cellular immune system.

  19. Adipose tissue PCB levels and CYP1B1 and COMT genotypes in relation to breast cancer risk in postmenopausal Danish women.

    PubMed

    Bräuner, Elvira V; Loft, Steffen; Wellejus, Anja; Autrup, Herman; Tjønneland, Anne; Raaschou-Nielsen, Ole

    2014-01-01

    Exposure to PCBs may be an etiologic factor for breast cancer. The cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) enzymes are involved in estrogen metabolism and PCB metabolism, both of which may relate to breast cancer susceptibility. Polymorphisms in genes regulating these enzymes control efficiency. Our objective was to assess whether CYP1B1 and COMT gene polymorphisms modulate the effect of PCBs in breast cancer risk, among postmenopausal Danish women. Neither CYP1B1 Leu432Val polymorphisms nor adipose tissue PCBs were independently associated with breast cancer risk. When assessing the independent effect of the COMT Val158Met polymorphism, we observed reduced risk for breast cancer amongst hormone replacement therapy using women who were homozygous carriers of the variant allele compared with those carrying the wild-type variant (RR = 0.41; 95% CI: 0.29-0.89). We found no statistically significant interactions between any of the PCB groups and CYP1B1 or COMT polymorphisms on the risk of breast cancer.

  20. Haemocoel injection of PirA1B1 to Galleria mellonella larvae leads to disruption of the haemocyte immune functions

    PubMed Central

    Wu, Gongqing; Yi, Yunhong

    2016-01-01

    The bacterium Photorhabdus luminescens produces a number of insecticidal proteins to kill its larval prey. In this study, we cloned the gene coding for a binary toxin PirA1B1 and purified the recombinant protein using affinity chromatography combined with desalination technology. Furthermore, the cytotoxicity of the recombinant protein against the haemocytes of Galleria mellonella larvae was investigated. We found that the protein had haemocoel insecticidal activity against G. mellonella with an LD50 of 131.5 ng/larva. Intrahaemocoelic injection of PirA1B1 into G. mellonella resulted in significant decreases in haemocyte number and phagocytic ability. In in vitro experiments, PirA1B1 inhibited the spreading behaviour of the haemocytes of G. mellonella larvae and even caused haemocyte degeneration. Fluorescence microscope analysis and visualization of haemocyte F-actin stained with phalloidin-FITC showed that the PirA1B1 toxin disrupted the organization of the haemocyte cytoskeleton. Our results demonstrated that the PirA1B1 toxin disarmed the insect cellular immune system. PMID:27734915

  1. Association of CYP1B1 Polymorphisms with Breast Cancer: A Case-Control Study in the Han Population in Ningxia Hui Autonomous Region, P. R. China

    PubMed Central

    Jiao, Haiyan; Liu, Chunlian; Guo, Weidong; Peng, Liang; Chen, Yintao; Martin, Francis L.

    2010-01-01

    Studies investigating possible associations between cytochrome P4501B1 (CYP1B1) polymorphisms and breast cancer risk have been inconsistent. We set out to ascertain whether there might be an association between polymorphisms in exon 2 (codon 119, G→T) and exon 3 (codon 432, G→C) of CYP1B1 and breast cancer in a Chinese Han population in the rural region of Ningxia. Using an allele-specific polymerase chain reaction method and direct DNA sequencing, the presence or absence of the two CYP1B1 polymorphisms was investigated. Genotype and allele frequencies were analyzed in breast cancer cases (n = 152) and healthy age-matched controls (n = 156). The odds ratio (OR) of 119G→T or 432G→C in breast cancer cases and controls was 3.3 (95% CI: 1.28 to 8.28) and 2.8 (95% CI: 1.04 to 7.51), respectively. In addition, the OR for people with both polymorphisms (119T and 432C) was 4.69 (95% CI: 1.97 to 11.19). Our results suggest that certain polymorphisms in the CYP1B1 gene might increase risk for breast cancer among Han Chinese, perhaps because they influence the efficiency of CYP1B1 bio-transformation of oestrogens or pro-carcinogens into DNA-reactive electrophiles that may act as cancer-initiating agents. PMID:20212917

  2. Metabolism of bilirubin by human cytochrome P450 2A6

    SciTech Connect

    Abu-Bakar, A'edah; Arthur, Dionne M.; Wikman, Anna S.; Rahnasto, Minna; Juvonen, Risto O.; Vepsäläinen, Jouko; Raunio, Hannu; Ng, Jack C.; Lang, Matti A.

    2012-05-15

    The mouse cytochrome P450 (CYP) 2A5 has recently been shown to function as hepatic “Bilirubin Oxidase” (Abu-Bakar, A., et al., 2011. Toxicol. Appl. Pharmacol. 257, 14–22). To date, no information is available on human CYP isoforms involvement in bilirubin metabolism. In this paper we provide novel evidence for human CYP2A6 metabolising the tetrapyrrole bilirubin. Incubation of bilirubin with recombinant yeast microsomes expressing the CYP2A6 showed that bilirubin inhibited CYP2A6-dependent coumarin 7-hydroxylase activity to almost 100% with an estimated K{sub i} of 2.23 μM. Metabolite screening by a high-performance liquid chromatography/electrospray ionisation mass spectrometry indicated that CYP2A6 oxidised bilirubin to biliverdin and to three other smaller products with m/z values of 301, 315 and 333. Molecular docking analyses indicated that bilirubin and its positively charged intermediate interacted with key amino acid residues at the enzyme's active site. They were stabilised at the site in a conformation favouring biliverdin formation. By contrast, the end product, biliverdin was less fitting to the active site with the critical central methylene bridge distanced from the CYP2A6 haem iron facilitating its release. Furthermore, bilirubin treatment of HepG2 cells increased the CYP2A6 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A6 compared to cells treated only with CHX. Collectively, the observations indicate that the CYP2A6 may function as human “Bilirubin Oxidase” where bilirubin is potentially a substrate and a regulator of the enzyme. -- Highlights: ► Human CYP2A6 interacts with bilirubin with a high affinity. ► Bilirubin docking to the CYP2A6 active site is more stable than biliverdin docking. ► Recombinant CYP2A6 microsomes metabolised bilirubin to biliverdin. ► Bilirubin increased the hepatic CYP2

  3. No association between CYP1B1 Val432Leu polymorphism and breast cancer risk: a meta-analysis involving 40,303 subjects.

    PubMed

    Yao, Lei; Fang, Fang; Wu, Qi; Zhong, Yang; Yu, Long

    2010-07-01

    Breast cancer is the most common cancer in women. To date, many publications have evaluated the association between Cytochrome P450 1B1 (CYP1B1) Val432Leu polymorphism and breast cancer risk. However, the results remain inconclusive. In order to derive a more precise estimation of the association, a meta-analysis was performed in this study. By searching Medline, Pubmed, and ISI Web of Knowledge databases, 26 studies including 19,028 cases and 21,275 controls were collected for CYP1B1 Val432Leu polymorphism. Crude ORs with 95% CIs were used to assess the strength of association between CYP1B1 Val432Leu polymorphism and breast cancer risk. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, no significant associations between CYP1B1 Val432Leu polymorphism and breast cancer susceptibility were found for Val/Val versus Leu/Leu (OR = 0.98; 95% CI: 0.90-1.06), Val/Leu versus Leu/Leu (OR = 1.01; 95% CI: 0.93-1.09), Val/Val + Val/Leu versus Leu/Leu (OR = 1.00; 95% CI: 0.93-1.08) and Val/Val versus Val/Leu + Leu/Leu (OR = 0.96; 95% CI: 0.91-1.01). In the stratified analysis by ethnicity, menopausal status and sources of controls, significant associations were still not observed in all genetic models. In conclusion, this meta-analysis provides strong evidence that CYP1B1 Val432Leu polymorphism is not associated with breast cancer risk.

  4. Interactions between genetic polymorphism of cytochrome P450-1B1, sulfotransferase 1A1, catechol-o-methyltransferase and tobacco exposure in breast cancer risk.

    PubMed

    Saintot, Monique; Malaveille, Christian; Hautefeuille, Agnès; Gerber, Mariette

    2003-11-20

    Genetic polymorphisms of enzymes involved in the metabolism of xenobiotics and estrogens might play a role in breast carcinogenesis related to environmental exposures. In a case-only study on 282 women with breast cancer, we studied the interaction effects (ORi) between smoking habits and the gene polymorphisms of Cytochrome P450 1B1 (Val432Leu CYP1B1), Phenol-sulfotransferase 1A1 (Arg213His SULT1A1) and Catechol-O-methyltransferase (Val158Met COMT). The smokers carrying the Val CYP1B1 allele associated with a high hydroxylation activity had a higher risk of breast cancer than never smokers with the Leu/Leu genotype (ORi=2.32, 95%CI: 1.00-5.38). Also, the smokers carrying the His SULT1A1 allele associated with a low sulfation activity had a 2-fold excess risk compared to never smokers carrying Arg/Arg SULT1A1 common genotype (ORi= 2.55, 95%CI: 1.21-5.36). The His SULT1A1 allele increased the risk only in premenopausal patients. The Met COMT allele with a lower methylation activity than Val COMT did not modify the risk among smokers. The excess risk due to joint effect could result from a higher exposure to activated tobacco-compounds for women homo/heterozygous for the Val CYP1B1 allele. Also, a lower sulfation of the tobacco carcinogens among women with His SULT1A1 could increase exposure to genotoxic compounds. Alternatively, the Val CYP1B1 or His SULT1A1 allele with modified ability to metabolize estrogens could increase the level of genotoxic catechol estrogen (i.e., 4-hydroxy-estradiol) among smokers. Our study showed that gene polymorphisms of CYP1B1 and SULT1A1 induce an individual susceptibility to breast cancer among current smokers.

  5. 2,3′,4,5′-Tetramethoxystilbene prevents deoxycorticosterone-salt-induced hypertension: contribution of cytochrome P-450 1B1

    PubMed Central

    Sahan-Firat, Seyhan; Jennings, Brett L.; Yaghini, Fariborz A.; Song, Chi Young; Estes, Anne M.; Fang, Xiao R.; Farjana, Nasreen; Khan, Amir I.

    2010-01-01

    Reactive oxygen species (ROS) contribute to various models of hypertension, including deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Recently, we have shown that ROS, generated by cytochrome P-450 1B1 (CYP1B1) from arachidonic acid, mediate vascular smooth muscle cell growth caused by angiotensin II. This study was conducted to determine the contribution of CYP1B1 to hypertension and associated pathophysiological changes produced by DOCA (30 mg/kg) given subcutaneously per week with 1% NaCl + 0.1% KCl in drinking water to uninephrectomized rats for 6 wk. DOCA-salt treatment increased systolic blood pressure (SBP). Injections of the selective inhibitor of CYP1B1, 2,3′,4,5′-tetramethoxystilbene (TMS; 300 μg/kg ip every 3rd day) initiated at the 4th week of DOCA-salt treatment normalized SBP and decreased CYP1B1 activity but not its expression in the aorta, heart, and kidney. TMS also inhibited cardiovascular and kidney hypertrophy, prevented the increase in vascular reactivity and endothelial dysfunction, and minimized the increase in urinary protein and K+ output and the decrease in urine osmolality, Na+ output, and creatinine clearance associated with DOCA-salt treatment. These pathophysiological changes caused by DOCA-salt treatment and associated increase in vascular superoxide production, NADPH oxidase activity, and expression of NOX-1, and ERK1/2 and p38 MAPK activities in the aorta, heart, and kidney were inhibited by TMS. These data suggest that CYP1B1 contributes to DOCA-salt-induced hypertension and associated pathophysiological changes, most likely as a result of increased ROS production and ERK1/2 and p38 MAPK activity, and could serve as a novel target for the development of agents like TMS to treat hypertension. PMID:20852048

  6. 7,12-Dimethylbenzanthracene induces apoptosis in RL95-2 human endometrial cancer cells: Ligand-selective activation of cytochrome P450 1B1

    SciTech Connect

    Kim, Ji Young; Lee, Seung Gee; Chung, Jin-Yong; Kim, Yoon-Jae; Park, Ji-Eun; Oh, Seunghoon; Lee, Se Yong; Choi, Hong Jo; Yoo, Young Hyun; and others

    2012-04-15

    7,12-Dimethylbenzanthracene (DMBA), a polycyclic aromatic hydrocarbon, exhibits mutagenic, carcinogenic, immunosuppressive, and apoptogenic properties in various cell types. To achieve these functions effectively, DMBA is modified to its active form by cytochrome P450 1 (CYP1). Exposure to DMBA causes cytotoxicity-mediated apoptosis in bone marrow B cells and ovarian cells. Although uterine endometrium constitutively expresses CYP1A1 and CYP1B1, their apoptotic role after exposure to DMBA remains to be elucidated. Therefore, we chose RL95-2 endometrial cancer cells as a model system for studying DMBA-induced cytotoxicity and cell death and hypothesized that exposure to DMBA causes apoptosis in this cell type following CYP1A1 and/or CYP1B1 activation. We showed that DMBA-induced apoptosis in RL95-2 cells is associated with activation of caspases. In addition, mitochondrial changes, including decrease in mitochondrial potential and release of mitochondrial cytochrome c into the cytosol, support the hypothesis that a mitochondrial pathway is involved in DMBA-induced apoptosis. Exposure to DMBA upregulated the expression of AhR, Arnt, CYP1A1, and CYP1B1 significantly; this may be necessary for the conversion of DMBA to DMBA-3,4-diol-1,2-epoxide (DMBA-DE). Although both CYP1A1 and CYP1B1 were significantly upregulated by DMBA, only CYP1B1 exhibited activity. Moreover, knockdown of CYP1B1 abolished DMBA-induced apoptosis in RL95-2 cells. Our data show that RL95-2 cells are susceptible to apoptosis by exposure to DMBA and that CYP1B1 plays a pivotal role in DMBA-induced apoptosis in this system. -- Highlights: ► Cytotoxicity-mediated apoptogenic action of DMBA in human endometrial cancer cells. ► Mitochondrial pathway in DMBA-induced apoptosis of RL95-2 endometrial cancer cells. ► Requirement of ligand-selective activation of CYP1B1 in DMBA-induced apoptosis.

  7. CYP2A6 polymorphisms and risk for tobacco-related cancers.

    PubMed

    Rossini, Ana; de Almeida Simão, Tatiana; Albano, Rodolpho Mattos; Pinto, Luis Felipe Ribeiro

    2008-11-01

    Tobacco consumption is the main identifiable risk to cancer, contributing to the majority of tumors in upper aerodigestive tissues. The psychoactive compound responsible for tobacco addiction, nicotine and the potent carcinogens present at high concentrations either in cigarette mainstream smoke or in smokeless tobacco products, 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK) and N-nitrosonornicotine (NNN) can be metabolized by CYP2A6. CYP2A6 is expressed in many aerodigestive tissues with high interindividual variability. The CYP2A6 gene is highly polymorphic and CYP2A6 alleles coding for enzymes with altered expression or metabolic capacity produce alterations in nicotine metabolism in vivo and seem to influence smoking behavior. These polymorphisms may change the rate of NNK and NNN activation and, therefore, may influence cancer risk associated with tobacco consumption. However, to date only a few and inconclusive studies have addressed the risk that a given CYP2A6 polymorphism presents for the development of tobacco-related tumors. Most, but not all, show a reduced risk associated with alleles that result in decreased enzyme activity. The overlapping substrate specificity and tissue expression between CYP2A6 and the highly similar CYP2A13 may add to the conflicting results observed. The intricate regulation of CYP2A6 and the variation of structurally different chemical compounds capable of inhibiting CYP2A enzymes also add to the complexity. Finally, the interaction between polymorphisms of genes that code for CYP2A6, CYP2A13 and other potent carcinogen-metabolizing CYP enzymes may help to determine individuals that are at higher risk of developing tumors associated with tobacco consumption.

  8. The cancer preventative agent resveratrol is converted to the anticancer agent piceatannol by the cytochrome P450 enzyme CYP1B1

    PubMed Central

    Potter, G A; Patterson, L H; Wanogho, E; Perry, P J; Butler, P C; Ijaz, T; Ruparelia, K C; Lamb, J H; Farmer, P B; Stanley, L A; Burke, M D

    2002-01-01

    Resveratrol is a cancer preventative agent that is found in red wine. Piceatannol is a closely related stilbene that has antileukaemic activity and is also a tyrosine kinase inhibitor. Piceatannol differs from resveratrol by having an additional aromatic hydroxy group. The enzyme CYP1B1 is overexpressed in a wide variety of human tumours and catalyses aromatic hydroxylation reactions. We report here that the cancer preventative agent resveratrol undergoes metabolism by the cytochrome P450 enzyme CYP1B1 to give a metabolite which has been identified as the known antileukaemic agent piceatannol. The metabolite was identified by high performance liquid chromatography analysis using fluorescence detection and the identity of the metabolite was further confirmed by derivatisation followed by gas chromatography–mass spectrometry studies using authentic piceatannol for comparison. This observation provides a novel explanation for the cancer preventative properties of resveratrol. It demonstrates that a natural dietary cancer preventative agent can be converted to a compound with known anticancer activity by an enzyme that is found in human tumours. Importantly this result gives insight into the functional role of CYP1B1 and provides evidence for the concept that CYP1B1 in tumours may be functioning as a growth suppressor enzyme. British Journal of Cancer (2002) 86, 774–778. DOI: 10.1038/sj/bjc/6600197 www.bjcancer.com © 2002 Cancer Research UK PMID:11875742

  9. Frequencies of single-nucleotide polymorphisms and haplotypes of the SLCO1B1 gene in selected populations of the western balkans

    PubMed Central

    Grapci, A Daka; Dimovski, AJ; Kapedanovska, A; Vavlukis, M; Eftimov, A; Geshkovska, N Matevska; Labachevski, N; Jakjovski, K; Gorani, D; Kedev, S; Mladenovska, K

    2015-01-01

    As a membrane influx transporter, organic anion-transporting polypeptide 1B1 (OATP1B1) regulates the cellular uptake of a number of endogenous compounds and drugs. The aim of this study was to characterize the diversity of the solute carrier organic anion transporter family member 1B1 (SLCO1B1) gene encoding this transporter in two ethnic groups populating the Western Balkans. The distribution of SCLO1B1 alleles was determined at seven variant sites (c.388A>G, c.521T>C, c.571T>C, c.597C>T, c.1086C>T, c.1463G>C and c.*439T>G) in 266 Macedonians and 94 Albanians using the TaqMan allelic discrimination assay. No significant difference in the frequencies of the single nucleotide polymorphisms (SNPs) was observed between these populations. The frequency of the c.521T>C SNP was the lowest (<13.7 and 12.2%, respectively), while the frequencies of all other SNP alleles were above 40.0%. Variant alleles of c.1463G>C and c.1086 C>T SNPs were not identified in either ethnic group. The haplotype analysis revealed 20 and 21 different haplotypes in the Macedonian and Albanian population, respectively. The most common haplotype in both ethnic groups, *1J/*1K/*1L, had a frequency of 39.0% and 26.6%, respectively. In both populations, the variant alleles of the functionally significant c.521T>C and c.388A>G SNPs existed in one major haplotype (*15/*16/*17), with a frequency of 8.6 and 2.4% in the Macedonian and Albanian subjects, respectively. In conclusion, sequence variations of the SLCO1B1 gene in the studied populations occur at high frequencies, which are similar to that of the Caucasian population. Further studies are needed to evaluate the clinical significance of these SNPs and/ or the major SLCO1B1 haplotypes they form for a large number of substrates and for susceptibility to certain diseases. PMID:26929901

  10. Frequencies of single-nucleotide polymorphisms and haplotypes of the SLCO1B1 gene in selected populations of the western balkans.

    PubMed

    Grapci, A Daka; Dimovski, A J; Kapedanovska, A; Vavlukis, M; Eftimov, A; Geshkovska, N Matevska; Labachevski, N; Jakjovski, K; Gorani, D; Kedev, S; Mladenovska, K

    2015-06-01

    As a membrane influx transporter, organic anion-transporting polypeptide 1B1 (OATP1B1) regulates the cellular uptake of a number of endogenous compounds and drugs. The aim of this study was to characterize the diversity of the solute carrier organic anion transporter family member 1B1 (SLCO1B1) gene encoding this transporter in two ethnic groups populating the Western Balkans. The distribution of SCLO1B1 alleles was determined at seven variant sites (c.388A>G, c.521T>C, c.571T>C, c.597C>T, c.1086C>T, c.1463G>C and c.*439T>G) in 266 Macedonians and 94 Albanians using the TaqMan allelic discrimination assay. No significant difference in the frequencies of the single nucleotide polymorphisms (SNPs) was observed between these populations. The frequency of the c.521T>C SNP was the lowest (<13.7 and 12.2%, respectively), while the frequencies of all other SNP alleles were above 40.0%. Variant alleles of c.1463G>C and c.1086 C>T SNPs were not identified in either ethnic group. The haplotype analysis revealed 20 and 21 different haplotypes in the Macedonian and Albanian population, respectively. The most common haplotype in both ethnic groups, *1J/*1K/*1L, had a frequency of 39.0% and 26.6%, respectively. In both populations, the variant alleles of the functionally significant c.521T>C and c.388A>G SNPs existed in one major haplotype (*15/*16/*17), with a frequency of 8.6 and 2.4% in the Macedonian and Albanian subjects, respectively. In conclusion, sequence variations of the SLCO1B1 gene in the studied populations occur at high frequencies, which are similar to that of the Caucasian population. Further studies are needed to evaluate the clinical significance of these SNPs and/ or the major SLCO1B1 haplotypes they form for a large number of substrates and for susceptibility to certain diseases.

  11. Soy isoflavones, CYP1A1, CYP1B1, and COMT polymorphisms, and breast cancer: a case-control study in southwestern China.

    PubMed

    Wang, Qiong; Li, Hui; Tao, Ping; Wang, Yuan-Ping; Yuan, Ping; Yang, Chun-Xia; Li, Jia-Yuan; Yang, Fei; Lee, Hui; Huang, Yuan

    2011-08-01

    CYP1A1, CYP1B1, and COMT are key enzymes involved in estrogen metabolism. Soy isoflavones, phytoestrogens found in soy foods, may modify the activity of these enzymes. A case-control study was conducted to assess the associations between soy isoflavone intake and the CYP1A1 Ile462Val, CYP1B1 Val432Leu, and COMT Val158Met polymorphisms and breast cancer, as well as their combined effects on breast cancer. A total of 400 newly diagnosed breast cancer cases and 400 healthy controls were recruited. Participants' daily intake of soy isoflavones (DISI [mg/day]) was calculated and transformed to energy-adjusted DISI by the residual method. Gene sequencing was used to analyze CYP1A1, CYP1B1, and COMT polymorphisms. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were estimated by conditional logistic regression. A strong protective dose-dependent effect of energy-adjusted DISI on breast cancer was found in both pre- and postmenopausal women (P(trend) < 0.05). Among all women and in the postmenopausal subgroup, COMT Met/Met and CYP1B1 Leu/Leu susceptible genotype carriers had higher risk of breast cancer (aORs > 1, OR 95% CIs exclude 1). In premenopausal women, only carrying CYP1B1 Leu/Leu was associated with breast cancer risk (aOR = 2.05, 95% CI: 1.11-3.79). Carrying CYP1A1 Val/Val was related to breast cancer risk only among all women. A stratified analysis was performed at two levels of energy-adjusted DISI, with wildtype homozygous genotypes and low energy-adjusted DISI as the reference. In the high energy-adjusted DISI subgroup, carrying the CYP1B1 Leu/Leu genotype did not affect breast cancer risk in either all women or in the menopausal subgroups, compared with the reference. Overall, in Han Chinese women, carrying CYP1A1 Val/Val and COMT Met/Met appears to be associated with breast cancer risk, especially in postmenopausal women. CYP1B1 susceptible genotypes (Val/Leu or Leu/Leu) also contribute to increased breast cancer risk

  12. Variation in CYP2A6 and tobacco dependence throughout adolescence and in young adult smokers

    PubMed Central

    Chenoweth, Meghan J.; Sylvestre, Marie-Pierre; Contreras, Gisele; Novalen, Maria; O’Loughlin, Jennifer; Tyndale, Rachel F.

    2015-01-01

    Background Smoking is influenced by genetic factors including variation in CYP2A6 and CYP2B6, which encode nicotine-metabolizing enzymes. In early adolescence, CYP2A6 slow nicotine metabolism was associated with higher dependence acquisition, but reduced cigarette consumption. Here we extend this work by examining associations of CYP2A6 and CYP2B6 with tobacco dependence acquisition in a larger sample of smokers followed throughout adolescence. Methods White participants from the Nicotine Dependence in Teens cohort that had ever inhaled (n=421) were followed frequently from age 12–18 years. Cox’s proportional hazards models compared the risk of ICD-10 tobacco dependence acquisition (score 3+) for CYP2A6 and CYP2B6 metabolism groups. Early smoking experiences, as well as amount smoked at end of follow-up, was also computed. At age 24 (N=162), we assessed concordance between self-reported cigarette consumption and salivary cotinine. Results In those who initiated inhalation during follow-up, CYP2A6 slow (vs. normal) metabolizers were at greater risk of dependence (hazards ratio (HR)=2.3; 95% CI=1.1, 4.8); CYP2B6 slow (vs. normal) metabolizers had non-significantly greater risk (HR=1.5; 95% CI=0.8, 2.6). Variation in CYP2A6 or CYP2B6 was not significantly associated with early smoking symptoms or cigarette consumption at end of follow-up. At age 24, neither gene was significantly associated with dependence status. Self-reported consumption was associated with salivary cotinine, a biomarker of tobacco exposure, acquired at age 24 (B=0.37; P<0.001). Conclusions Our findings extend previous work indicating that slow nicotine metabolism mediated by CYP2A6, and perhaps CYP2B6, increases risk for tobacco dependence throughout adolescence. PMID:26644138

  13. Functional and Structural Analyses of CYP1B1 Variants Linked to Congenital and Adult-Onset Glaucoma to Investigate the Molecular Basis of These Diseases

    PubMed Central

    Chakrabarti, Saikat; Ray, Kunal

    2016-01-01

    Glaucoma, the leading cause of irreversible blindness, appears in various forms. Mutations in CYP1B1 result in primary congenital glaucoma (PCG) by an autosomal recessive mode of inheritance while it acts as a modifier locus for primary open angle glaucoma (POAG). We investigated the molecular basis of the variable phenotypes resulting from the defects in CYP1B1 by using subclones of 23 CYP1B1 mutants reported in glaucoma patients, in a cell based system by measuring the dual activity of the enzyme to metabolize both retinol and 17β-estradiol. Most variants linked to POAG showed low steroid metabolism while null or very high retinol metabolism was observed in variants identified in PCG. We examined the translational turnover rates of mutant proteins after the addition of cycloheximide and observed that the levels of enzyme activity mostly corroborated the translational turnover rate. We performed extensive normal mode analysis and molecular-dynamics-simulations-based structural analyses and observed significant variation of fluctuation in certain segmental parts of the mutant proteins, especially at the B-C and F-G loops, which were previously shown to affect the dynamic behavior and ligand entry/exit properties of the cytochrome P450 family of proteins. Our molecular study corroborates the structural analysis, and suggests that the pathologic state of the carrier of CYP1B1 mutations is determined by the allelic state of the gene. To our knowledge, this is the first attempt to dissect biological activities of CYP1B1 for correlation with congenital and adult onset glaucomas. PMID:27243976

  14. Novel ATP6V1B1 and ATP6V0A4 mutations in autosomal recessive distal renal tubular acidosis with new evidence for hearing loss.

    PubMed

    Stover, E H; Borthwick, K J; Bavalia, C; Eady, N; Fritz, D M; Rungroj, N; Giersch, A B S; Morton, C C; Axon, P R; Akil, I; Al-Sabban, E A; Baguley, D M; Bianca, S; Bakkaloglu, A; Bircan, Z; Chauveau, D; Clermont, M-J; Guala, A; Hulton, S A; Kroes, H; Li Volti, G; Mir, S; Mocan, H; Nayir, A; Ozen, S; Rodriguez Soriano, J; Sanjad, S A; Tasic, V; Taylor, C M; Topaloglu, R; Smith, A N; Karet, F E

    2002-11-01

    Autosomal recessive distal renal tubular acidosis (rdRTA) is characterised by severe hyperchloraemic metabolic acidosis in childhood, hypokalaemia, decreased urinary calcium solubility, and impaired bone physiology and growth. Two types of rdRTA have been differentiated by the presence or absence of sensorineural hearing loss, but appear otherwise clinically similar. Recently, we identified mutations in genes encoding two different subunits of the renal alpha-intercalated cell's apical H(+)-ATPase that cause rdRTA. Defects in the B1 subunit gene ATP6V1B1, and the a4 subunit gene ATP6V0A4, cause rdRTA with deafness and with preserved hearing, respectively. We have investigated 26 new rdRTA kindreds, of which 23 are consanguineous. Linkage analysis of seven novel SNPs and five polymorphic markers in, and tightly linked to, ATP6V1B1 and ATP6V0A4 suggested that four families do not link to either locus, providing strong evidence for additional genetic heterogeneity. In ATP6V1B1, one novel and five previously reported mutations were found in 10 kindreds. In 12 ATP6V0A4 kindreds, seven of 10 mutations were novel. A further nine novel ATP6V0A4 mutations were found in "sporadic" cases. The previously reported association between ATP6V1B1 defects and severe hearing loss in childhood was maintained. However, several patients with ATP6V0A4 mutations have developed hearing loss, usually in young adulthood. We show here that ATP6V0A4 is expressed within the human inner ear. These findings provide further evidence for genetic heterogeneity in rdRTA, extend the spectrum of disease causing mutations in ATP6V1B1 and ATP6V0A4, and show ATP6V0A4 expression within the cochlea for the first time.

  15. Novel ATP6V1B1 and ATP6V0A4 mutations in autosomal recessive distal renal tubular acidosis with new evidence for hearing loss

    PubMed Central

    Stover, E; Borthwick, K; Bavalia, C; Eady, N; Fritz, D; Rungroj, N; Giersch, A; Morton, C; Axon, P; Akil, I; Al-Sabban, E; Baguley, D; Bianca, S; Bakkaloglu, A; Bircan, Z; Chauveau, D; Clermont, M; Guala, A; Hulton, S; Kroes, H; Li, V; Mir, S; Mocan, H; Nayir, A; Ozen, S; Rodriguez, S; Sanjad, S; Tasic, V; Taylor, C; Topaloglu, R; Smith, A; Karet, F

    2002-01-01

    Autosomal recessive distal renal tubular acidosis (rdRTA) is characterised by severe hyperchloraemic metabolic acidosis in childhood, hypokalaemia, decreased urinary calcium solubility, and impaired bone physiology and growth. Two types of rdRTA have been differentiated by the presence or absence of sensorineural hearing loss, but appear otherwise clinically similar. Recently, we identified mutations in genes encoding two different subunits of the renal α-intercalated cell's apical H+-ATPase that cause rdRTA. Defects in the B1 subunit gene ATP6V1B1, and the a4 subunit gene ATP6V0A4, cause rdRTA with deafness and with preserved hearing, respectively. We have investigated 26 new rdRTA kindreds, of which 23 are consanguineous. Linkage analysis of seven novel SNPs and five polymorphic markers in, and tightly linked to, ATP6V1B1 and ATP6V0A4 suggested that four families do not link to either locus, providing strong evidence for additional genetic heterogeneity. In ATP6V1B1, one novel and five previously reported mutations were found in 10 kindreds. In 12 ATP6V0A4 kindreds, seven of 10 mutations were novel. A further nine novel ATP6V0A4 mutations were found in "sporadic" cases. The previously reported association between ATP6V1B1 defects and severe hearing loss in childhood was maintained. However, several patients with ATP6V0A4 mutations have developed hearing loss, usually in young adulthood. We show here that ATP6V0A4 is expressed within the human inner ear. These findings provide further evidence for genetic heterogeneity in rdRTA, extend the spectrum of disease causing mutations in ATP6V1B1 and ATP6V0A4, and show ATP6V0A4 expression within the cochlea for the first time. PMID:12414817

  16. Pharmacokinetic interactions between glimepiride and rosuvastatin in healthy Korean subjects: does the SLCO1B1 or CYP2C9 genetic polymorphism affect these drug interactions?

    PubMed Central

    Kim, Choon Ok; Oh, Eun Sil; Kim, Hohyun; Park, Min Soo

    2017-01-01

    To improve cardiovascular outcomes, dyslipidemia in patients with diabetes needs to be treated. Thus, these patients are likely to take glimepiride and rosuvastatin concomitantly. Therefore, this study aimed to evaluate the pharmacokinetic (PK) interactions between these two drugs in healthy males and to explore the effect of SLCO1B1 and CYP2C9 polymorphisms on their interactions in two randomized, open-label crossover studies. Glimepiride was studied in part 1 and rosuvastatin in part 2. Twenty-four participants were randomly assigned to each part. All subjects (n=24) completed part 1, and 22 subjects completed part 2. A total of 38 subjects among the participants of the PK interaction studies were enrolled in the genotype study to analyze their SLCO1B1 and CYP2C9 polymorphisms retrospectively (n=22 in part 1, n=16 in part 2). Comparison of the PK and safety of each drug alone with those of the drugs in combination showed that both glimepiride and rosuvastatin did not interact with each other and had tolerable safety profiles in all subjects. However, with regard to glimepiride PK, the SLCO1B1 521TC group had a significantly higher maximum plasma concentration (Cmax,ss) and area under the plasma concentration–time curve during the dose interval at steady state (AUCτ,ss) for glimepiride in combination with rosuvastatin than those for glimepiride alone. However, other significant effects of the SLCO1B1 or CYP2C9 polymorphism on the interaction between the two drugs were not observed. In conclusion, there were no significant PK interactions between the two drugs; however, the exposure to glimepiride could be affected by rosuvastatin in the presence of the SLCO1B1 polymorphism. PMID:28260863

  17. Carnosol, a Constituent of Zyflamend, Inhibits Aryl Hydrocarbon Receptor-Mediated Activation of CYP1A1 and CYP1B1 Transcription and Mutagenesis

    PubMed Central

    Mohebati, Arash; Guttenplan, Joseph B.; Kochhar, Amit; Zhao, Zhong-Lin; Kosinska, Wieslawa; Subbaramaiah, Kotha; Dannenberg, Andrew J.

    2012-01-01

    The aryl hydrocarbon receptor (AhR), a ligand-activated member of the basic-helix-loop-helix family of transcription factors, plays a significant role in polycyclic aromatic hydrocarbon (PAH) induced carcinogenesis. In the upper aerodigestive tract of humans, tobacco smoke, a source of PAHs, activates the AhR leading to increased expression of CYP1A1 and CYP1B1, which encode proteins that convert PAHs to genotoxic metabolites. Inhibitors of Hsp90 ATPase cause a rapid decrease in levels of AhR, an Hsp90 client protein, and thereby block PAH-mediated induction of CYP1A1 and CYP1B1. The main objective of this study was to determine whether Zyflamend, a polyherbal preparation, suppressed PAH-mediated induction of CYP1A1 and CYP1B1 and inhibited DNA adduct formation and mutagenesis. We also investigated whether carnosol, one of multiple phenolic antioxidants in Zyflamend, had similar inhibitory effects. Treatment of cell lines derived from oral leukoplakia (MSK-Leuk1) and skin (HaCaT) with benzo[a]pyrene (B[a]P), a prototypic PAH, induced CYP1A1 and CYP1B1 transcription, resulting in enhanced levels of message and protein. Both Zyflamend and carnosol suppressed these effects of B[a]P. Notably, both Zyflamend and carnosol inhibited Hsp90 ATPase activity and caused a rapid reduction in AhR levels. The formation of B[a]P induced DNA adducts and mutagenesis were also inhibited by Zyflamend and carnosol. Collectively, these results show that Zyflamend and carnosol inhibit Hsp90 ATPase leading to reduced levels of AhR, suppression of B[a]P-mediated induction of CYP1A1 and CYP1B1 and inhibition of mutagenesis. Carnosol-mediated inhibition of Hsp90 ATPase activity can help explain the chemopreventive activity of herbs such as Rosemary, which contain this phenolic antioxidant. PMID:22374940

  18. CYP1A1 and CYP1B1 polymorphisms and their association with estradiol and estrogen metabolites in women who are premenopausal and perimenopausal.

    PubMed

    Sowers, MaryFran R; Wilson, Angela L; Kardia, Sharon R; Chu, Jian; McConnell, Daniel S

    2006-09-01

    The purpose of this study was to relate measured concentrations of estradiol (E2) and the urinary estrogen metabolites 2-hydroxyestrone (2-OHE1) and 16alpha-hydroxyestrone (16alpha-OHE1) to single nucleotide polymorphisms (SNPs) from CYP1A1 and CYP1B1, the primary genes involved in estrogen catabolism. We investigated the association of 4 CYP1A1 SNPs (CYP1A1 rs4646903, CYP1A1 rs1531163, CYP1A1 rs2606345, and CYP1A1 rs1048943) and 2 CYP1B1 SNPs (CYP1B1 rs162555 and CYP1B1 rs1056836) to circulating serum E2 concentrations and the urinary estrogen metabolites 2-OHE1 and 16alpha-OHE1. The associations were evaluated in 1,340 participants of 4 racial/ethnic groups from the Study of Women's Health Across the Nation (SWAN) who were premenopausal and perimenopausal. There was substantial variation in the allele frequencies of the SNPs for African American and Caucasian women. There was, however, remarkable comparability between Chinese and Japanese women; their CYP1A1 and CYP1B1 allele frequencies differed by only < or =11%. There was significant variation in E2 concentrations by genotype within racial/ethnic group for CYP1A1 rs2606345. In particular, Japanese women with the CC genotype had lower E2 concentrations than did Japanese women with the AC genotype. Chinese women with the CC genotype had higher 2-OHE1 concentrations than did Chinese women with the AC genotype. Further, African American women with the CC genotype had higher 16alpha-OHE1 concentrations than did those with other genotypes. CYP1A1 rs2606345 may play an important role in estrogen metabolism in women who are premenopausal and perimenopausal.

  19. Mutational spectrum of the CYP1B1 gene in Pakistani patients with primary congenital glaucoma: Novel variants and genotype-phenotype correlations

    PubMed Central

    Sheikh, Shakeel Ahmed; Narsani, Ashok Kumar; Shaikh, Hina; Gilal, Imtiaz Ahmed; Shah, Khairuddin; Qasim, Muhammad; Memon, Azam Iqbal; Kewalramani, Pitambar; Shaikh, Naila

    2014-01-01

    Purpose This study aimed to investigate the role of CYP1B1 mutations in primary congenital glaucoma (PCG) in Pakistani patients. Methods After consent was received, 20 families with at least more than one member affected with primary congenital glaucoma were enrolled in the study. The disease was confirmed with standard ophthalmological investigations. Genomic DNA was extracted from whole blood for localization of linkage and sequencing. Bioinformatics tools were used to assess the predicted pathological role of novel variants. Results Ten out of 20 families (50%, 10/20) showed homozygosity with CYP1B1-linked short tandem repeat (STR) markers. On direct sequencing of the CYP1B1 gene in the linked families, six mutations, including two novel pathogenic variants, were identified. p. R390H was the most frequently found mutation in five families (50%, 5/10), whereas c.868_869insC, p.E229K, and p.A115P were found once in three families. Two novel mutations, a missense mutation (p.G36D) and an in-frame deletion mutation (p.G67-A70del), were segregated with disease phenotype in two families. Age of disease onset was congenital in all mutations; however, disease severity and response to clinical interventions varied among the mutations and families. Haplotype analysis using five polymorphisms revealed a distinct haplotype for a common mutation. Conclusions This is the largest cohort of Pakistani patients with PCG to be genetically screened for CYP1B1 mutations. Identifying common mutation and genotype-phenotype correlations may help in genetic testing and better prognosis for the disease. Novel mutations identified in the study may help in better understanding the pathophysiology of CYP1B1-associated glaucoma. PMID:25018621

  20. Meta- and pooled analyses of the cytochrome P-450 1B1 Val432Leu polymorphism and breast cancer: a HuGE-GSEC review.

    PubMed

    Paracchini, Valentina; Raimondi, Sara; Gram, Inger T; Kang, Daehee; Kocabas, Neslihan A; Kristensen, Vessela N; Li, Donghui; Parl, Fritz F; Rylander-Rudqvist, Tove; Soucek, Pavel; Zheng, Wei; Wedren, Sara; Taioli, Emanuela

    2007-01-15

    The association between the cytochrome P-450 1B1 (CYP1B1) Val432Leu polymorphism and breast cancer was assessed through a meta-analysis of all published case-control studies and a pooled analysis of both published and unpublished case-control studies from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database ( www.upci.upmc.edu/research/ccps/ccontrol/g_intro.html ). GSEC is a collaborative project that gathers information on studies of metabolic gene polymorphisms and cancer. Thirteen articles were included in the meta-analysis (14,331 subjects; 7,514 cases, 6,817 controls); nine data sets were included in the pooled analysis (6,842 subjects; 3,391 cases, 3,451 controls). A summary meta- or pooled estimate of the association between the CYP1B1 Val432Leu polymorphism and breast cancer could not be calculated because of statistically significant heterogeneity in the point estimates among studies. No association between the CYP1B1 Val432Leu polymorphism and breast cancer was observed in Asians (for Val/Val and Val/Leu combined, odds ratio (OR) = 1.0, 95% confidence interval (CI): 0.8, 1.2). An inverse association was observed in populations of mixed/African origin (OR = 0.8, 95% CI: 0.7, 0.9). The pooled analysis suggested a possible association in Caucasians (for Val/Val and Val/Leu combined, OR = 1.5, 95% CI: 1.1, 2.1), with effect modification across age categories. The observed effect of age on the association in Caucasians indicates that further studies are needed on the role of CYP1B1 Val432Leu in estrogen metabolism according to age, ethnicity, and menopausal status.

  1. The influence of macrolide antibiotics on the uptake of organic anions and drugs mediated by OATP1B1 and OATP1B3.

    PubMed

    Seithel, Annick; Eberl, Sonja; Singer, Katrin; Auge, Daniel; Heinkele, Georg; Wolf, Nadine B; Dörje, Frank; Fromm, Martin F; König, Jörg

    2007-05-01

    Macrolides may cause severe drug interactions due to the inhibition of metabolizing enzymes. Transporter-mediated uptake of drugs into cells [e.g., by members of the human organic anion transporting polypeptide (OATP) family] is a determinant of drug disposition and a prerequisite for subsequent metabolism. However whether macrolides are also inhibitors of uptake transporters, thereby providing an additional mechanism of drug interactions, has not been systematically studied. The human OATP family members OATP1B1 and OATP1B3 mediate the uptake of endogenous substances and drugs such as antibiotics and HMG-CoA reductase inhibitors (statins) into hepatocytes. In this study we investigated the potential role of these uptake transporters on macrolide-induced drug interactions. By using sulfobromophthalein (BSP) and the HMG-CoA reductase inhibitor pravastatin as substrates, the effects of the macrolides azithromycin, clarithromycin, erythromycin, and roxithromycin and of the ketolide telithromycin on the OATP1B1- and OATP1B3-mediated uptake were analyzed. These experiments demonstrated that the OATP1B1- and OATP1B3-mediated uptake of BSP and pravastatin can be inhibited by increasing concentrations of all macrolides except azithromycin. The IC50 values for the inhibition of OATP1B3-mediated BSP uptake were 11 microM for telithromycin, 32 microM for clarithromycin, 34 microM for erythromycin, and 37 microM for roxithromycin. These IC50 values were lower than the IC50 values for inhibition of OATP1B1-mediated BSP uptake (96-217 microM). These macrolides also inhibited in a concentration-dependent manner the OATP1B1- and OATP1B3-mediated uptake of pravastatin. In summary, these results indicate that alterations of uptake transporter function by certain macrolides/ketolides have to be considered as a potential additional mechanism underlying drug-drug interactions.

  2. The SLCO1B1 rs4149032 Polymorphism Is Highly Prevalent in South Africans and Is Associated with Reduced Rifampin Concentrations: Dosing Implications▿

    PubMed Central

    Chigutsa, Emmanuel; Visser, Marianne E.; Swart, Elizabeth C.; Denti, Paolo; Pushpakom, Sudeep; Egan, Deirdre; Holford, Nicholas H. G.; Smith, Peter J.; Maartens, Gary; Owen, Andrew; McIlleron, Helen

    2011-01-01

    Among patients with tuberculosis, rifampin plasma concentrations and sputum conversion rates have been reported to be lower in Africans. Rifampin is a substrate of P-glycoprotein (coded for by the ABCB1 gene) and organic anion-transporting polypeptide 1B1 (coded for by SLCO1B1). The objectives were to identify genetic polymorphisms of drug transporters and the transcriptional regulators pregnane X receptor (PXR) and constitutive androstane receptor (CAR) with an impact on rifampin pharmacokinetics in South Africans. Fifty-seven patients with tuberculosis from Cape Town underwent pharmacokinetic sampling during treatment with rifampin, pyrazinamide, isoniazid, and ethambutol. DNA was genotyped for ABCB1, SLCO1B1, PXR, and CAR polymorphisms by using real-time PCR. NONMEM was used for data analysis. The allele frequency of the SLCO1B1 rs4149032 polymorphism was 0.70. Patients heterozygous and homozygous for this polymorphism had reductions in the bioavailability (and, thus, the area under the curve [AUC]) of rifampin of 18% and 28%, respectively. Simulations showed that increasing the daily rifampin dose by 150 mg in patients with the polymorphism would result in plasma concentrations similar to those of wild-type individuals and reduce the percentage of patients with peak plasma concentrations (Cmax) below 8 mg/liter from 63% to 31%. ABCB1, PXR, and CAR polymorphisms were not associated with differences in rifampin pharmacokinetics. SLCO1B1 rs4149032 was present in most patients and was associated with substantially reduced rifampin exposure. These data suggest that the standard recommended dose of rifampin should be reconsidered for South Africans. PMID:21709081

  3. CXCR4 promotes cisplatin-resistance of non-small cell lung cancer in a CYP1B1-dependent manner.

    PubMed

    Xie, Songping; Tu, Zhenbo; Xiong, Jie; Kang, Ganjun; Zhao, Lina; Hu, Weidong; Tan, Haiyan; Tembo, Kingsley Miyanda; Ding, Qianshan; Deng, Xinzhou; Huang, Jie; Zhang, Qiuping

    2017-02-01

    Chemoresistance is the main cause of treatment failure and high mortality in advanced lung cancer. Cisplatin, an important chemotherapeutic agent for lung cancer, has been observed to show enormously reduced chemotherapeutic efficacy owing to the development of chemoresistance. CXCR4, a stromal-derived-factor-1 specific chemokine receptor, is highly expressed in non-small cell lung cancer (NSCLC) tissues and participates in cancer progression by regulating cell growth, apoptosis or invasion. In this study, we therefore investigated whether CXCR4 plays a role in the cisplatin associated resistance in NSCLC. We detected the expression of CXCR4 in tissue specimens from 64 NSCLC patients by immunohistochemistry. Cisplatin-resistant NSCLC cells A549/DDP and its parental A549 cells were employed in this study. RNA interference was performed to silence the CXCR4. The influence of CXCR4 on tumor cell chemoresistance, apoptosis and growth, as well as the relationship between CXCR4 and the expression of cytochrome p450 associated molecule CYP1B1 in NSCLC were evaluated. Finally, we found CXCR4 was significantly highly expressed in cisplatin-resistant NSCLC patients and the A549/DDP cell line. CXCR4 inhibition by siRNA reversed chemoresistance and decreased tumor cell proliferation. Bioinformatics analysis showed that the expression of CYP1B1 had a positive correlation with CXCR4, the CYP1B1 silencing significantly decreased CXCR4 expression levels and cisplatin resistance. Immunohistochemistry also verified that CYP1B1 was upregulated in NSCLC tissues of cisplatin-resistant patients. In conclusion, our results indicate that overexpression of CXCR4 in NSCLC promotes cisplatin resistance via CXCR4-mediated CYP1B1 upregulation. Thus, it can be used as a potential therapeutic target in NSCLC chemoresistance patients and be used as a clinical predictor of cisplatin response.

  4. Effects of the 5-HT receptor antagonists GR127935 (5-HT1B/1D) and MDL100907 (5-HT2A) in the consolidation of learning.

    PubMed

    Meneses, A; Terrón, J A; Hong, E

    1997-12-01

    We have previously reported that 5-HT1B/1D and 5-HT2A/2B/2C receptors play a role in learning and memory. The present investigation was devoted to analyze further in the autoshaping learning task: (1) the effects of the 5-HT1A/1B/1D receptor agonist, GR46611, the 5-HT1B/1D receptor antagonist, GR127935, and the selective 5-HT2A receptor antagonist, MDL100907. Consistent with a role of 5-HT1B/1D receptors in learning, the post-training injection of GR46611 (1-10 mg/kg) decreased the consolidation of learning whereas GR127935 (10 mg/kg) increased it; the effects of both drugs were reversed by PCA pretreatment. GR127935 abolished the decrease induced by GR46611, TFMPP and mCPP, whereas MDL100907 (0.1-3.0 mg/kg) had no effect by itself but abolished the effects of DOI, ketanserin and TFMPP and moderately inhibited the effects elicited by mCPP, 1-NP and mesulergine. Neither did GR127935 nor MDL100907 significantly modify the increase in the consolidation of learning induced by 8-OH-DPAT. Thus, the present findings suggest that stimulation of presynaptic 5-HT1B/1D receptors impairs the consolidation of learning whilst stimulation of 5-HT2A/2C receptors enhances it; the blockade of 5-HT2A receptors has no effects. In addition, 5-HT2 receptors seem to modulate this cognitive stage.

  5. Pharmacogenetics of OATP Transporters Reveals That SLCO1B1 c.388A>G Variant Is Determinant of Increased Atorvastatin Response

    PubMed Central

    Rodrigues, Alice C.; Perin, Paula M. S.; Purim, Sheila G.; Silbiger, Vivian N.; Genvigir, Fabiana D. V.; Willrich, Maria Alice V.; Arazi, Simone S.; Luchessi, Andre D.; Hirata, Mario H.; Bernik, Marcia M. S.; Dorea, Egidio L.; Santos, Carla; Faludi, Andre A.; Bertolami, Marcelo C.; Salas, Antonio; Freire, Ana; Lareu, Maria V.; Phillips, Christopher; Porras-Hurtado, Liliana; Fondevila, Manuel; Carracedo, Angel; Hirata, Rosario D. C.

    2011-01-01

    Aims The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. Material and Methods One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected and treated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot® and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (−71T>C) gene polymorphisms were identified by TaqMan® Real-time PCR. Results Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3–8.0, p < 0.05). Conclusion SLCO1B1 c.388A>G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy. PMID:22016628

  6. Nicotine Metabolism and Smoking: Ethnic Differences in the Role of P450 2A6.

    PubMed

    Murphy, Sharon E

    2017-01-17

    Nicotine is the primary addictive agent in tobacco, and P450 2A6 (gene name: CYP2A6) is the primary catalyst of nicotine metabolism. It was proposed more than 20 years ago that individuals who metabolize nicotine poorly would smoke less, either fewer cigarettes per day or less intensely per cigarette, compared to smokers who metabolize nicotine more efficiently. These poor metabolizers would then be less likely to develop lung cancer due to their lower exposure to the many carcinogens delivered with nicotine in each puff of smoke. Numerous studies have reported that smokers who carry reduced activity or null CYP2A6 alleles do smoke less. Yet only in Asian populations, both Japanese and Chinese, which have a high prevalence of genetic variants, has a link between CYP2A6, smoking dose, and lung cancer been established. In other ethnic groups, it has been challenging to confirm a direct link between P450 2A6-mediated nicotine metabolism and the risk of lung cancer. This challenge is due in part to the difficulty in accurately quantifying smoking dose and accurately predicting or measuring P450 2A6-mediated nicotine metabolism. Biomarkers of nicotine metabolism and smoking exposure, including the ratio of trans-3-hydroxycotine to cotinine, a measure of P450 2A6 activity and plasma cotinine, or urinary total nicotine equivalents (the sum of nicotine and six metabolites) as measures of exposure are useful for addressing this challenge. However, to take full advantage of these biomarkers in the study of ethnic/racial differences in the risk of lung cancer requires the complete characterization of nicotine metabolism across ethnic/racial groups. Variation in metabolism pathways, other than those catalyzed by P450 2A6, can impact biomarkers of both nicotine metabolism and dose. This is clearly important for smokers with low levels of UGT2B10-catalyzed nicotine and cotinine glucuronidation because the UGT2B10 genotype influences plasma cotinine levels. Cotinine is not

  7. Differential Effects of Glycyrrhiza Species on Genotoxic Estrogen Metabolism: Licochalcone A Downregulates P450 1B1, whereas Isoliquiritigenin Stimulates It.

    PubMed

    Dunlap, Tareisha L; Wang, Shuai; Simmler, Charlotte; Chen, Shao-Nong; Pauli, Guido F; Dietz, Birgit M; Bolton, Judy L

    2015-08-17

    Estrogen chemical carcinogenesis involves 4-hydroxylation of estrone/estradiol (E1/E2) by P450 1B1, generating catechol and quinone genotoxic metabolites that cause DNA mutations and initiate/promote breast cancer. Inflammation enhances this effect by upregulating P450 1B1. The present study tested the three authenticated medicinal species of licorice [Glycyrrhiza glabra (GG), G. uralensis (GU), and G. inflata (GI)] used by women as dietary supplements for their anti-inflammatory activities and their ability to modulate estrogen metabolism. The pure compounds, liquiritigenin (LigF), its chalcone isomer isoliquiritigenin (LigC), and the GI-specific licochalcone A (LicA) were also tested. The licorice extracts and compounds were evaluated for anti-inflammatory activity by measuring inhibition of iNOS activity in macrophage cells: GI ≫ GG > GU and LigC ≅ LicA ≫ LigF. The Michael acceptor chalcone, LicA, is likely responsible for the anti-inflammatory activity of GI. A sensitive LC-MS/MS assay was employed to quantify estrogen metabolism by measuring 2-MeOE1 as nontoxic and 4-MeOE1 as genotoxic biomarkers in the nontumorigenic human mammary epithelial cell line, MCF-10A. GG, GU, and LigC increased 4-MeOE1, whereas GI and LicA inhibited 2- and 4-MeOE1 levels. GG, GU (5 μg/mL), and LigC (1 μM) also enhanced P450 1B1 expression and activities, which was further increased by inflammatory cytokines (TNF-α and IFN-γ). LicA (1, 10 μM) decreased cytokine- and TCDD-induced P450 1B1 gene expression and TCDD-induced xenobiotic response element luciferase reporter (IC50 = 12.3 μM), suggesting an antagonistic effect on the aryl hydrocarbon receptor, which regulates P450 1B1. Similarly, GI (5 μg/mL) reduced cytokine- and TCDD-induced P450 1B1 gene expression. Collectively, these data suggest that, of the three licorice species that are used in botanical supplements, GI represents the most promising chemopreventive licorice extract for women's health. Additionally, the

  8. Gender, but not CYP7A1 or SLCO1B1 polymorphism, affects the fasting plasma concentrations of bile acids in human beings.

    PubMed

    Xiang, Xiaoqiang; Backman, Janne T; Neuvonen, Pertti J; Niemi, Mikko

    2012-03-01

    Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme of bile acid production in human beings, and organic anion-transporting polypeptide 1B1 (OATP1B1) may influence bile acid hepatic uptake and cholesterol and bile acid synthesis rate. Our purpose was to investigate the effects of gender and CYP7A1 and SLCO1B1 polymorphisms on the fasting plasma concentrations of bile acids, bile acid synthesis marker and total cholesterol in a Finnish population. Fasting plasma concentrations of 16 endogenous bile acids, their synthesis marker (7α-hydroxy-4-cholesten-3-one) and total cholesterol were measured in 243 samples from 143 healthy volunteers. The volunteers were genotyped for 6 haplotype-tagging single-nucleotide polymorphisms (SNPs) of CYP7A1 and two functionally relevant SNPs in SLCO1B1. The mean plasma concentrations of chenodeoxycholic acid, glycochenodeoxycholic acid, ursodeoxycholic acid and glycoursodeoxycholic acid were 61-111% higher in men than in women (P ≤ 0.001). Accordingly, the mean concentration of total bile acids was 51% higher in men than in women (P = 0.001). The CYP7A1 rs8192879 and rs1023652 SNPs were associated with deoxycholic acid and hyodeoxycholic acid concentrations, respectively, but the associations were not significant after correction for multiple testing. None of the six CYP7A1 SNPs was associated with the plasma concentrations of cholesterol or 7α-hydroxy-4-cholesten-3-one. SLCO1B1 genotype was associated with total plasma cholesterol concentration only, but the association was not significant after correction for multiple testing. In general, the gender contributes substantially more to variation in fasting plasma bile acid concentrations than CYP7A1 or SLCO1B1 polymorphism do. Common genetic variability in CYP7A1 is unlikely to play a significant role in cholesterol metabolism and bile acid homeostasis under normal physiological conditions.

  9. Application of a fuzzy neural network model in predicting polycyclic aromatic hydrocarbon-mediated perturbations of the Cyp1b1 transcriptional regulatory network in mouse skin

    SciTech Connect

    Larkin, Andrew; Siddens, Lisbeth K.; Krueger, Sharon K.; Tilton, Susan C.; Waters, Katrina M.; Williams, David E.; Baird, William M.

    2013-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are present in the environment as complex mixtures with components that have diverse carcinogenic potencies and mostly unknown interactive effects. Non-additive PAH interactions have been observed in regulation of cytochrome P450 (CYP) gene expression in the CYP1 family. To better understand and predict biological effects of complex mixtures, such as environmental PAHs, an 11 gene input-1 gene output fuzzy neural network (FNN) was developed for predicting PAH-mediated perturbations of dermal Cyp1b1 transcription in mice. Input values were generalized using fuzzy logic into low, medium, and high fuzzy subsets, and sorted using k-means clustering to create Mamdani logic functions for predicting Cyp1b1 mRNA expression. Model testing was performed with data from microarray analysis of skin samples from FVB/N mice treated with toluene (vehicle control), dibenzo[def,p]chrysene (DBC), benzo[a]pyrene (BaP), or 1 of 3 combinations of diesel particulate extract (DPE), coal tar extract (CTE) and cigarette smoke condensate (CSC) using leave-one-out cross-validation. Predictions were within 1 log{sub 2} fold change unit of microarray data, with the exception of the DBC treatment group, where the unexpected down-regulation of Cyp1b1 expression was predicted but did not reach statistical significance on the microarrays. Adding CTE to DPE was predicted to increase Cyp1b1 expression, whereas adding CSC to CTE and DPE was predicted to have no effect, in agreement with microarray results. The aryl hydrocarbon receptor repressor (Ahrr) was determined to be the most significant input variable for model predictions using back-propagation and normalization of FNN weights. - Highlights: ► Tested a model to predict PAH mixture-mediated changes in Cyp1b1 expression ► Quantitative predictions in agreement with microarrays for Cyp1b1 induction ► Unexpected difference in expression between DBC and other treatments predicted ► Model predictions

  10. Excitation of the \\tilde{a}\\,^3B_1 and \\tilde{A}\\,^1B_1 states of H2O by low-energy electron impact

    NASA Astrophysics Data System (ADS)

    Hargreaves, L.; Ralphs, K.; Serna, G.; Khakoo, M. A.; Winstead, C.; McKoy, V.

    2012-10-01

    We report measured and calculated differential cross-sections for inelastic scattering of low-energy electrons by water leading to excitation of the dissociative (1b1 → 4a1) 1, 3B1 states. The measurements were taken using conventional energy-loss spectroscopy at incident energies of 9, 10, 12, 15, and 20 eV for scattering angles from 10° to 130°. The calculations were carried out using the Schwinger multichannel method, with a Born-dipole correction applied in the singlet excitation channel. Integral excitation cross sections for the \\tilde{a}\\,^3B_1 and \\tilde{A}\\,^1B_1 states are also derived from the differential cross section results.

  11. CYP1B1 gene mutations with incomplete penetrance in a Chinese pedigree with primary congenital glaucoma: a case report and review of literatures

    PubMed Central

    Chen, Ling; Huang, Lina; Zeng, Aineng; He, Jing

    2015-01-01

    To investigate the cytochrome P4501B1 (CYP1B1) mutations in a three-generation Chinese Han family with PCG, the 2 and 3 coding exons of CYP1B1 gene were amplified by PCR, and were directly sequenced using Sanger bidirectional sequencing reactions. The mutation c.517 G>A p.E173K was detected in all the affected individuals (which showed homozygous AA genotype) and not in all the unaffected ones except one individual. The mutation c.517 G>A p.E173K is associated with disease causing in this pedigree. And the possible genetic model is recessive inheritance. One apparently unaffected individual had mutations and haplotypes identical to her affected sibs suggested incomplete penetrance in this pedigree. PMID:26550445

  12. CYP1B1 G199T Polymorphism Affects Prognosis of NSCLC Patients with the Potential to Be an Indicator and Target for Precise Drug Intervention

    PubMed Central

    Zhang, Shaofeng; Zhang, Qi; Zhao, Shilei

    2017-01-01

    CYP1B1 gene single nucleotide polymorphisms G119T, C432G, and A453G were tested among 164 NSCLC patients treated by Video-Assisted Thoracoscopic Surgery. After a follow-up period of 5 years, it was found that CYP1B1 G119T mutant genotypes were related to a higher risk of tumor recurrence and death after surgical resection. However, C432G and A453G genotypes had no influence on long-term prognosis of the study cohort. Thus, G199T alleles are supposed to be an auxiliary predictor for prognosis of NSCLC patients and a potential target for precise drug intervention, as well as a candidate for further anticancer drug research. PMID:28377924

  13. Genetic polymorphism analysis of the drug-metabolizing enzyme CYP1A2 in a Uyghur Chinese population: a pilot study.

    PubMed

    Geng, Tingting; Zhang, Xi Yang; Wang, Li; Wang, Huijuan; Shi, Xugang; Kang, Longli; Hou, Peng; Jin, Tianbo

    2016-01-01

    1. CYP1A2 is a highly polymorphic gene and CYP1A2 enzyme results in broad inter-individual variability in response to certain pharmacotherapies, while little is known about the genetic variation of CYP1A2 in Uyghur Chinese population. The aim of the present study was to screen Uyghur volunteers for CYP1A2 genetic polymorphisms. 2. We used DNA sequencing to investigate promoter, exons, introns, and 3' UTR of the CYP1A2 gene in 96 unrelated healthy Uyghur individuals. We also used SIFT (Sorting Intolerant From Tolerant) and PolyPhen-2 (Polymorphism Phenotyping v2) to predict the protein function of the novel non-synonymous mutation in CYP1A2 coding regions. 3. We identified 20 different CYP1A2 polymorphisms in the Uyghur Chinese population, including two novel variants (119A > G and 2410G > A). Variant 119A > G was predicted to be probably damaging on protein function by PolyPhen-2, by contrast, 2410G > A was identified as benign. The allele frequencies of CYP1A2*1A, *1B, *1F, *1G, *1J, *1M, *4, and *9 were 23.4%, 53.1%, 3.7%, 2.6%, 2.6%, 13.5%, 0.5%, and 0.5%, respectively. The frequency of *1F, a putative high inducibility allele, was higher in our sample population compared with that in the Caucasian population (p < 0.05). The most common genotype combinations were *1A/*1B (46.9%) and *1B/*1M (27.1%). 4. Our results provide basic information on CYP1A2 polymorphisms in Uyghur individuals and suggest that the enzymatic activities of CYP1A2 may differ among the diverse ethnic populations of the world.

  14. Investigation of binding features: effects on the interaction between CYP2A6 and inhibitors.

    PubMed

    Ai, Chunzhi; Li, Yan; Wang, Yonghua; Li, Wei; Dong, Peipei; Ge, Guangbo; Yang, Ling

    2010-07-15

    A computational investigation has been carried out on CYP2A6 and its naphthalene inhibitors to explore the crucial molecular features contributing to binding specificity. The molecular bioactive orientations were obtained by docking (FlexX) these compounds into the active site of the enzyme. And the density functional theory method was further used to optimize the molecular structures with the subsequent analysis of molecular lipophilic potential (MLP) and molecular electrostatic potential (MEP). The minimal MLPs, minimal MEPs, and the band gap energies (the energy difference between the highest occupied molecular orbital and lowest unoccupied molecular orbital) showed high correlations with the inhibition activities (pIC(50)s), illustrating their significant roles in driving the inhibitor to adopt an appropriate bioactive conformation oriented in the active site of CYP2A6 enzyme. The differences in MLPs, MEPs, and the orbital energies have been identified as key features in determining the binding specificity of this series of compounds to CYP2A6 and the consequent inhibitory effects. In addition, the combinational use of the docking, MLP and MEP analysis is also demonstrated as a good attempt to gain an insight into the interaction between CYP2A6 and its inhibitors.

  15. Structural Insight into the Altered Substrate Specificity of Human Cytochrome P450 2A6 Mutants

    PubMed Central

    Sansen, Stefaan; Hsu, Mei-Hui; Stout, C. David; Johnson, Eric F.

    2009-01-01

    Human P450 2A6 displays a small active site that is well adapted for the oxidation of small planar substrates. Mutagenesis of CYP2A6 resulted in an increased catalytic efficiency for indole biotransformation to pigments and conferred a capacity to oxidize substituted indoles (Wu, Z.-L., Podust, L.M. and Guengerich, F.P. (2005) J.Biol.Chem. 49, 41090-41100). Here, we describe the structural basis that underlies the altered metabolic profile of three mutant enzymes, P450 2A6 N297Q, L240C/N297Q and N297Q/I300V. The Asn297 substitution abolishes a potential hydrogen bonding interaction with substrates in the active site, and replaces a structural water molecule between the helix B′-C region and helix I while maintaining structural hydrogen bonding interactions. The structures of the P450 2A6 N297Q/L240C and N297Q/I300V mutants provide clues as to how the protein can adapt to fit the larger substituted indoles in the active site, and enable a comparison with other P450 family 2 enzymes for which the residue at the equivalent position was seen to function in isozyme specificity, structural integrity and protein flexibility. PMID:17540336

  16. Functional evaluation of novel single nucleotide polymorphisms and haplotypes in the promoter regions of CYP1B1 and CYP1A1 genes.

    PubMed

    Han, Weiguo; Pentecost, Brian T; Spivack, Simon D

    2003-07-01

    Interindividual variation in the expression of the carcinogen- and estrogen-metabolizing enzymes cytochrome P4501B1 and 1A1 (CYP1B1 and CYP1A1) has been detected in human lung. To search for polymorphisms with functional consequences for CYP1B1 and CYP1A1 gene expression, we examined 1.5 kb of the promoter region of each gene. Genomic DNA from 21 Caucasian individuals was amplified by polymerase chain reaction (PCR) for direct cycle sequencing. Eight single nucleotide polymorphisms (SNPs) for CYP1B1 and 13 SNPs for CYP1A1 were found. The majority of polymorphisms occurred as multiSNP combinations for individual subjects. The wild-type sequences were cloned into a luciferase reporter construct. The most frequent polymorphisms were then recreated by iterative site-directed mutagenesis, replicating single polymorphisms and multiSNP combinations. These wild-type and variant constructs were functionally evaluated in transient transfection experiments employing exposures to either the index polycyclic aromatic hydrocarbon (PAH) inducer benzo[a]pyrene (B[a]P), a composite mixture of cigarette smoke extract (CSE), or the repressor chemopreventive agent trans-3,4,5-trihydroxystilbene (reseveratrol). Results indicated that all wild-type and variant constructs responded in qualitatively concordant fashion to the inducers and to the repressor. The CYP1B1 haplotypes and the majority of CYP1A1 haplotypes were shown to have no functional consequence, as compared to those of the wild-type promoter sequences. Two constructs of composite polymorphisms of CYP1A1 appeared to result in a statistically significant increase in basal promoter activity (1.38- and 1.50-fold, respectively), but the degree of functional impact was judged unlikely to be biologically important in vivo. We conclude that the observed promoter region polymorphisms in these genes are common, but are of unclear functional consequence.

  17. Organic anion transporting polypeptide (OATP)1B1 and OATP1B3 as important regulators of the pharmacokinetics of substrate drugs.

    PubMed

    Maeda, Kazuya

    2015-01-01

    Nobody doubts the importance of organic anion transporting polypeptide (OATP)1B1 and 1B3 in the clinical pharmacokinetics of substrate drugs. Based on the theory of pharmacokinetics, even if a drug is eliminated from the body by extensive metabolism, the rate-determining process of the hepatic intrinsic clearance of OATP substrates is often hepatic uptake. Because of their broad substrate specificities, once the functions of OATP1B1 or OATP1B3 are altered by several kinds of special occasions such as drug-drug interactions (DDI) and genetic polymorphisms of transporter genes, the hepatic clearance of many kinds of structurally-unrelated drugs is expected to be changed. In some cases, these alterations of pharmacokinetics lead to modified pharmacological effects and adverse reactions such as statin-induced myotoxicity and the glucose-lowering effect of anti-diabetes drugs. Thus, appropriate methods with which to quantitatively predict the changes in plasma and tissue concentrations of drugs are needed in the process of drug development. As for DDI, a static model that takes into consideration of the theoretically-maximum unbound inhibitor concentration is often used for the sensitive detection of possible DDI risks and this method has been adopted in several regulatory guidance/guidelines on DDI. Regarding genetic polymorphisms, the effects of SLCO1B1 c.388A>G and c.521T>C on the pharmacokinetics of substrate drugs have been extensively investigated. Even though there are some discrepancies, c.521T>C generally decreased hepatic uptake activity, while c.388A>G tended to slightly increase it. This article briefly summarizes the current status of research on hepatic OATP1B1 and OATP1B3 and the clinical significance of their functions.

  18. Application of a Fuzzy Neural Network Model in Predicting Polycyclic Aromatic Hydrocarbon- Mediated Perturbations of the Cyp1b1 Transcriptional Regulatory Network in Mouse Skin

    PubMed Central

    Larkin, Andrew; Siddens, Lisbeth K.; Krueger, Sharon K.; Tilton, Susan C.; Waters, Katrina M.; Williams, David E.; Baird, William M.

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are present in the environment as complex mixtures with components that have diverse carcinogenic potencies and mostly unknown interactive effects. Non-additive PAH interactions have been observed in regulation of cytochrome P450 (CYP) gene expression in the CYP1 family. To better understand and predict biological effects of complex mixtures, such as environmental PAHs, an 11 gene input-1 gene output fuzzy neural network (FNN) was developed for predicting PAH-mediated perturbations of dermal Cyp1b1 transcription in mice. Input values were generalized using fuzzy logic into low, medium, and high fuzzy subsets, and sorted using k-means clustering to create Mamdani logic functions for predicting Cyp1b1 mRNA expression. Model testing was performed with data from microarray analysis of skin samples from FVB/N mice treated with toluene (vehicle control), dibenzo[def,p]chrysene (DBC), benzo[a]pyrene (BaP), or 1 of 3 combinations of diesel particulate extract (DPE), coal tar extract (CTE) and cigarette smoke condensate (CSC) using leave one out cross-validation. Predictions were within 1 log2 fold change unit of microarray data, with the exception of the DBC treatment group, where the unexpected down-regulation of Cyp1b1 expression was predicted but did not reach statistical significance on the microarrays. Adding CTE to DPE was predicted to increase Cyp1b1 expression, whereas adding CSC to CTE and DPE was predicted to have no effect, in agreement with microarray results. The aryl hydrocarbon receptor repressor (Ahrr) was determined to be the most significant input variable for model predictions using back-propagation and normalization of FNN weights. PMID:23274566

  19. [The CYP1B1 and CYP2F1 genes polymorphisms frequency in three ethnic groups of Bashkortostan and chronic obstructive pulmonary disease patients].

    PubMed

    Korytina, G F; Akhmadishina, L Z; Viktorova, T V

    2010-01-01

    Chronic obstructive pulmonary disease is a multifactorial respiratory disorder. Members of the cytochrome P450 family catalyze the oxidative metabolism of exogenous chemicals and activate their substrates into reactive intermediates that may initiate lung injury. The aim of this study was to learn interethnic variation in frequency distribution patterns of CYP1B1 and CYP2F1 genes polymorphic markers and to analyse its association withchronic obstructive pulmonary disease. The polymorphic markers Leu432Val(CYP1B1) and c.14_15insC(CYP2F1) were studied at chronic obstructive pulmonary disease patients (Russian (N=169), Tatar (N=137)) and cases of healthy individuals (Russian (N=191), Tatar (N=198) and Bashkir (N=78)), residents of Bashkortostan by PCR-RFLP method. It was shown that the CYP2F1 gene genotype frequency distribution patterns differed between three ethnic groups (chi2 = 21.29, df=4, P = 0.0001), because of high frequency of c.14_15insC/c.14_15insC genotype in Tatars (6.38%). On the other hand, high frequency (39.74%) of normal/ c.14_15insC genotype was appeared in Bashkirs. Association analysis of CYP2F1 geneinsertion variant with chronic obstructive pulmonary disease have shown high frequency (87.5%) of normal allele in Tatars patients with very severe stage and manifestation of chronic obstructive pulmonary disease after 55 years (chi2 = 3.964, df=1, P = 0.046; OR = = 2.268). It was shown that allele and genotype frequency distribution of Leu432ValCYP1B1 gene not differed between Russian, Tatar and Bashkir ethnic groups. We did not find any association of Leu432Val CYP1B1 gene with chronic obstructive pulmonary disease.

  20. Concomitance of oncogenic HPV types, CHEK2 gene mutations, and CYP1B1 gene polymorphism as an increased risk factor for malignancy

    PubMed Central

    Constantinou, Maria; Pietrusiński, Michał; Kępczyński, Łukasz; Jędrzejczyk, Adam; Rożniecki, Marek; Marks, Piotr; Kałużewski, Bogdan

    2013-01-01

    Introduction Urinary bladder carcinoma ranks the fourth position in malignancy incidence rates in men (6.1%) and the 17th position in women (1.6%). In general, neoplastic diseases should be approached from two perspectives: prevention with implementation of prophylactic measures and early diagnostics. Prophylactics is possible in the preclinical phase of neoplasm, being both justified and plausible in patients from high–risk groups. Thus, it is particularly important to select such groups, not only by referring to environmental carcinogenic factors (occupational and extra–occupational) but also from genetic predisposition, which may be conductive for neoplasm formation. The mutations / polymorphisms of CHEK2 and CYP1B1 genes predispose to neoplasm via multiorgan mechanisms, while the human papilloma virus (HPV) may participate in the neoplastic transformation as an environmental factor. Material and methods 131 patients with diagnosed urinary bladder cancer were qualified to the study. Mutations/polymorphisms of CHEK2 (IVS2 + 1G > A gene, 1100delC, del5395, I157T) and CYP1B1– 355T/T were identified by the PCR in DNA isolated directly from the tumor and from peripheral blood. The ELISA test was used for the studies of 37 HPV genotypes in DNA, isolated tumour tissue. Results 11 mutations of CHEK2 gene were found, 355T/T polymorphism if CYP1B1 gene occurred in 18 patients (12.9%). Oncogenic HPV was found in 36 (29.3%), out of 123 examined patients. Conclusions The concomitance of CHEK2 gene mutations or 355T/T polymorphism of CYP1B1 gene and the presence of oncogenic HPV types statistically significantly correlates with histological malignancy grades of urinary bladder carcinoma. PMID:24578981

  1. Protein expression of CYP1A1, CYP1B1, ALDH1A1, and ALDH2 in young patients with oral squamous cell carcinoma.

    PubMed

    Kaminagakura, E; Caris, A; Coutinho-Camillo, C; Soares, F A; Takahama-Júnior, A; Kowalski, L P

    2016-06-01

    The purpose of this study was to evaluate the expression of the enzymes involved in the biotransformation of tobacco and alcohol. A study group of 41 young patients (≤40 years old) with oral squamous cell carcinoma (OSCC) was compared to 59 control subjects (≥50 years old) with tumours of similar clinical stages and topographies. The immunohistochemical expression of CYP1A1, CYP1B1, ALDH1A1, and ALDH2 was evaluated using the tissue microarray technique. There was a predominance of males, smokers, and alcohol drinkers in both groups. Most tumours were located in the tongue (43.9% vs. 50.8%), were well-differentiated (63.4% vs. 56.6%), and were in clinical stages III or IV (80.5% vs. 78.0%). No difference was observed in the expression of CYP1A1, ALDH1A1, or ALDH2 between the two groups. CYP1A1 and ALDH2 protein expression had no influence on the prognosis. The immunoexpression of CYP1B1 was significantly higher in the control group than in the young group (P<0.001). The 5-year relapse-free survival was better in patients with CYP1B1 overexpression vs. protein underexpression (64% vs. 25%; P<0.05), regardless of age. ALDH1A1 expression improved relapse-free survival in young patients. These results suggest a lower risk of recurrence with increased metabolism of carcinogens by CYP1B1. Further studies involving other genes and proteins are necessary to complement the results of this research.

  2. Role of androgen metabolism genes CYP1B1, PSA/KLK3, and CYP11alpha in prostate cancer risk and aggressiveness.

    PubMed

    Cicek, Mine S; Liu, Xin; Casey, Graham; Witte, John S

    2005-09-01

    Candidate genes involved with androgen metabolism have been hypothesized to affect the risk of prostate cancer. To further investigate this, we evaluated the relationship between prostate cancer and multiple potentially functional polymorphisms in three genes involved in androgen metabolism: CYP1B1 (two single nucleotide polymorphisms: 355G/T and 4326C/G), prostate-specific antigen (PSA/KLK3 (three single nucleotide polymorphisms: -158A/G, -4643G/A, and -5412C/T), and CYP11alpha [(tttta)(n) repeat], using a moderately large (n = 918) sibling-based case-control population. When looking at all subjects combined, no association was observed between any polymorphism-or their haplotypes-and prostate cancer risk. However, among men with more aggressive prostate cancer, the CYP1B1 355G/T variant was positively associated with disease: carrying one or two T alleles gave odds ratios (OR) of 1.90 [95% confidence interval (95% CI), 1.09-3.31; P = 0.02] and 3.73 (95% CI, 1.39-10.0; P = 0.009), respectively. Similarly, carrying the CYP1B1 355T-4326C haplotype was positively associated with prostate cancer among men with high aggressive disease (P = 0.01). In addition, the PSA -158G/-158G genotype was positively associated with prostate cancer among men with less aggressive disease (OR, 2.71; 95% CI, 1.06-6.94; P = 0.04). Our findings suggest that CYP1B1 and PSA variants may affect the risk of prostate cancer and tumor aggressiveness.

  3. Antiproliferative effect of the Ginkgo biloba extract is associated with the enhancement of cytochrome P450 1B1 expression in estrogen receptor-negative breast cancer cells.

    PubMed

    Zhao, Xiao-Dan; Dong, Ni; Man, Hong-Tao; Fu, Zhong-Lin; Zhang, Mei-Hong; Kou, Shuang; Ma, Shi-Liang

    2013-09-01

    Ginkgo biloba is a dioecious tree and its extract is a complex mixture that has been used for thousands of years to treat a variety of ailments in traditional Chinese medicine. The aim of this study was to present our observations on the inhibitory effects of different Ginkgo biloba extracts on human breast cancer cell proliferation and growth. Our results demonstrated that treatment of MCF-7 and MDA-MB-231 human breast cancer cells with Ginkgo biloba leaves and ginkgo fruit extract inhibited cell proliferation. It was also observed that this inhibition was accompanied by the enhancement of cytochrome P450 (CYP) 1B1 expression in MDA-MB-231 cells. In addition, treatment with ginkgo fruit extract resulted in a higher CYP1B1 expression in MDA-MB-231 cells compared to treatment with the Ginkgo biloba leaves extract. Our results suggested that the inhibitory effects of the Ginkgo biloba extract on estrogen receptor-negative breast cancer proliferation and the induction of CYP1B1 expression may be exerted through an alternative pathway, independent of the estrogen receptor or the aryl hydrocarbon receptor pathway.

  4. SLCO1B1 genetic variant associated with statin-induced myopathy: a proof-of-concept study using the clinical practice research datalink.

    PubMed

    Carr, D F; O'Meara, H; Jorgensen, A L; Campbell, J; Hobbs, M; McCann, G; van Staa, T; Pirmohamed, M

    2013-12-01

    This study aimed to determine whether patients with statin-induced myopathy could be identified using the United Kingdom Clinical Practice Research Datalink, whether DNA could be obtained, and whether previously reported associations of statin myopathy with the SLCO1B1 c.521T>C and COQ2 rs4693075 polymorphisms could be replicated. Seventy-seven statin-induced myopathy patients (serum creatine phosphokinase (CPK) > 4× upper limit of normal (ULN)) and 372 statin-tolerant controls were identified and recruited. Multiple logistic regression analysis showed the SLCO1B1 c.521T>C single-nucleotide polymorphism to be a significant risk factor (P = 0.009), with an odds ratio (OR) per variant allele of 2.06 (1.32-3.15) for all myopathy and 4.09 (2.06-8.16) for severe myopathy (CPK > 10× ULN, and/or rhabdomyolysis; n = 23). COQ2 rs4693075 was not associated with myopathy. Meta-analysis showed an association between c.521C>T and simvastatin-induced myopathy, although power for other statins was limited. Our data replicate the association of SLCO1B1 variants with statin-induced myopathy. Furthermore, we demonstrate how electronic medical records provide a time- and cost-efficient means of recruiting patients with severe adverse drug reactions for pharmacogenetic studies.

  5. Antiproliferative effect of the Ginkgo biloba extract is associated with the enhancement of cytochrome P450 1B1 expression in estrogen receptor-negative breast cancer cells

    PubMed Central

    ZHAO, XIAO-DAN; DONG, NI; MAN, HONG-TAO; FU, ZHONG-LIN; ZHANG, MEI-HONG; KOU, SHUANG; MA, SHI-LIANG

    2013-01-01

    Ginkgo biloba is a dioecious tree and its extract is a complex mixture that has been used for thousands of years to treat a variety of ailments in traditional Chinese medicine. The aim of this study was to present our observations on the inhibitory effects of different Ginkgo biloba extracts on human breast cancer cell proliferation and growth. Our results demonstrated that treatment of MCF-7 and MDA-MB-231 human breast cancer cells with Ginkgo biloba leaves and ginkgo fruit extract inhibited cell proliferation. It was also observed that this inhibition was accompanied by the enhancement of cytochrome P450 (CYP) 1B1 expression in MDA-MB-231 cells. In addition, treatment with ginkgo fruit extract resulted in a higher CYP1B1 expression in MDA-MB-231 cells compared to treatment with the Ginkgo biloba leaves extract. Our results suggested that the inhibitory effects of the Ginkgo biloba extract on estrogen receptor-negative breast cancer proliferation and the induction of CYP1B1 expression may be exerted through an alternative pathway, independent of the estrogen receptor or the aryl hydrocarbon receptor pathway. PMID:24649031

  6. Measuring electron-impact cross sections of water: elastic scattering and electronic excitation of the ã3B1 and Ã1B1 states

    NASA Astrophysics Data System (ADS)

    Matsui, Midori; Hoshino, Masamitsu; Kato, Hidetoshi; Ferreira da Silva, Fillipe; Limão-Vieira, Paulo; Tanaka, Hiroshi

    2016-04-01

    Here, we report elastic differential cross sections (DCSs) for electron scattering from water in the incident energy range of 2-100 eV. Furthermore, we present a complete study on the electronic excitation of the ã3B1 and Ã1B1 states at electron impact energies of 15, 20, and 30 eV and in the scattering angle range of 10° - 130°. Integral cross sections (ICSs) are determined from the DCSs. Measuring elastic DCSs in various experimental conditions confirmed the reproducibility of the data. The present results agree with the data previously obtained from a conventional collimating tube gas source. Ambiguities associated with the unfolding procedure of the electron energy loss (EEL) spectra for the electronic excitations have been reduced by comparison against the EEL spectrum at high electron impact energy and for small scattering angle. The reliability of the extracted DCSs is improved significantly for optically forbidden contributions from the overlap of the ã3B1 and Ã1B1 electronic states. The BEf-scaling model is also confirmed to produce the integral cross section for the optical allowed transition of the Ã1B1 state in the intermediate electron energy region above 15 eV.

  7. Association of the CYP1B1 Leu432Val polymorphism with the risk of prostate cancer: a meta-analysis.

    PubMed

    Cui, Lingling; Dillehay, Kelsey; Chen, Weimin; Shen, Deliang; Dong, Zhongyun; Li, Wenjie

    2012-07-01

    Cytochrome P450 1B1 (CYP1B1) is a key P450 enzyme involved in the metabolism of exogenous and endogenous substrates in endocrine-mediated tumors such as prostate cancer. The potential significance of nonsynonymous SNP Leu432Val (rs1056836) as a risk factor in prostate cancer has been extensively studied. The objective of this meta-analysis was to quantitatively summarize the association between CYP1B1 Leu432Val polymorphism and prostate cancer. All eligible studies were searched and acquired from the PubMed and ISI databases. Statistical analysis was performed by using the software STATA 11.0. Ten case-controlled studies from nine eligible publications were identified, which includes 6,668 subjects with 3,221 cases and 3,447 controls. Overall, no significant association was found between the CYP1B1 Leu432Val polymorphism and prostate cancer susceptibility for Val/Val vs Leu/Leu (OR = 1.07; 95% CI: 0.79-1.44; P = 0.67), Leu/Val vs Leu/Leu (OR = 1.05; 95% CI: 0.94-1.17; P = 0.42), Leu/Val + Val/Val vs Leu/Leu (OR = 1.07; 95% CI: 0.91-1.26; P = 0.40) and Val/Val vs Leu/Val + Leu/Leu (OR = 1.11; 95% CI: 0.86-1.44; P = 0.43). However, a higher risk was found among Asians in all genetic models (Val/Val vs Leu/Leu :OR = 2.48, 95% CI: 1.14-5.39, P = 0.02; Leu/Val vs Leu/Leu: OR = 1.40, 95% CI: 1.03-1.89, P = 0.03; Leu/Val + Val/Val vs Leu/Leu: OR = 1.51, 95% CI = 1.14-2.01, P = 0.004; Val/Val vs Leu/Val + Leu/Leu: OR = 2.50, 95% CI = 1.35-4.56, P = 0.004). We were not able to detect any association in the subgroup analysis by source of controls and genotyping method in all genetic models. In conclusion, this meta-analysis provides evidence that CYP1B1 Leu432Val polymorphism is not associated with prostate cancer risk overall with the exception in Asians.

  8. Polymorphisms in the cytochrome P450 CYP1A2 gene (CYP1A2) in colorectal cancer patients and controls: allele frequencies, linkage disequilibrium and influence on caffeine metabolism

    PubMed Central

    Sachse, Christoph; Bhambra, Upinder; Smith, Gillian; Lightfoot, Tracy J; Barrett, Jennifer H; Scollay, Jenna; Garner, R Colin; Boobis, Alan R; Wolf, C Roland; Gooderham, Nigel J

    2003-01-01

    Aim Several single nucleotide polymorphisms (SNPs) of the cytochrome P450 enzyme 1A2 gene (CYP1A2) have been reported. Here, frequencies, linkage disequilibrium and phenotypic consequences of six SNPs are described. Methods From genomic DNA, 114 British Caucasians (49 colorectal cancer cases and 65 controls) were genotyped for the CYP1A2 polymorphisms −3858G→A (allele CYP1A2*1C), −2464T→delT (CYP1A2*1D), −740T→G (CYP1A2*1E and *1G), −164A→C (CYP1A2*1F), 63C→G (CYP1A2*2), and 1545T→C (alleles CYP1A2*1B, *1G, *1H and *3), using polymerase chain reaction–restriction fragment length polymorphism assays. All patients and controls were phenotyped for CYP1A2 by h.p.l.c. analysis of urinary caffeine metabolites. Results In 114 samples, the most frequent CYP1A2 SNPs were 1545T→C (38.2% of tested chromosomes), −164A→C (CYP1A2*1F, 33.3%) and −2464T→delT (CYP1A2*1D, 4.82%). The SNPs were in linkage disequilibrium: the most frequent constellations were found to be −3858G/−2464T/−740T/−164A/63C/1545T (61.8%), −3858G/−2464T/−740T/−164C/63C/1545C (33.3%), and −3858G/−2464delT/−740T/−164A/63C/1545C (3.51%), with no significant frequency differences between cases and controls. In the phenotype analysis, lower caffeine metabolic ratios were detected in cases than in controls. This was significant in smokers (n = 14, P = 0.020), and in a subgroup of 15 matched case-control pairs (P = 0.007), but it was not significant in nonsmokers (n = 100, P = 0.39). There was no detectable association between CYP1A2 genotype and caffeine phenotype. Conclusions (i) CYP1A2 polymorphisms are in linkage disequilibrium. Therefore, only −164A→C (CYP1A2*1F) and −2464T→delT (CYP1A2*1D) need to be analysed in the routine assessment of CYP1A2 genotype; (ii) in vivo CYP1A2 activity is lower in colorectal cancer patients than in controls, and (iii) CYP1A2 genotype had no effect on phenotype (based on the caffeine metabolite ratio). However, this

  9. Combined effect of CYP1B1, COMT, GSTP1, and MnSOD genotypes and risk of postmenopausal breast cancer

    PubMed Central

    Cerne, Jasmina-Ziva; Pohar-Perme, Maja; Novakovic, Srdjan; Frkovic-Grazio, Snjezana; Stegel, Vida

    2011-01-01

    Objective Estrogen plays a key role in breast cancer development and functionally relevant genetic variants within the estrogen metabolic pathway are prime candidates for a possible association with breast cancer risk. We investigated the independent and the combined effects of commonly occurring polymorphisms in four genes encoding key proteins of estrogen metabolic pathway on their potential contribution to breast cancer risk. Methods We studied 530 breast cancer cases and 270 controls of the same age and ethnicity participating in a case-control study of postmenopausal women. Genotyping was conducted for CYP1B1 (rs1056836), COMT (rs4680), GSTP1 (rs1695), and MnSOD (rs4880) polymorphisms by polymerase chain reaction based restriction fragment length polymorphism and TaqMan allelic discrimination method. Adjusted ORs and 95% CIs were calculated using logistic regression. Results None of the 4 genetic variants examined contributed to breast cancer risk individually. When the combined effects of the risk genotypes were investigated, significant associations were observed among women with two high-risk genotypes in CYP1B1 and COMT (OR, 2.0; 95% CI, 1.1 to 3.5) and two high-risk genotypes in COMT and MnSOD (OR, 2.0; 95% CI, 1.0 to 3.8), compared to those with low-risk genotypes. Conclusion Our results suggest that individual susceptibility to breast cancer incidence may be increased by combined effects of the high-risk genotypes in CYP1B1, COMT, and MnSOD estrogen metabolic genes. PMID:21860737

  10. Association of single nucleotide polymorphisms in the CYP1B1 gene with the risk of primary open-angle glaucoma: a meta-analysis.

    PubMed

    Wang, Z; Li, M; Li, L; Sun, H; Lin, X Y

    2015-12-17

    Mutations in the CYP1B1 gene were detected in primary open-angle glaucoma (POAG) patients. However, the association between these mutations and the incidence of POAG remains to be elucidated. Here, we have conducted a meta-analysis to analyze this correlation, using relevant studies obtained from an extensive search of various electronic databases, including EMBase, Web of Science, and PubMed. The extracted studies were selected for the meta-analysis based on the inclusion and exclusion criteria. The quality of each included study was assessed by the Newcastle-Ottawa scale (NOS), and the I2 value was calculated to evaluate the heterogeneity between studies. The combined effect size was presented as the odds ratio (OR), and confidence intervals (CI) were used to assess the association between POAG and CYP1B1 mutations. Eight studies, each with a high NOS score, were included in the analysis. Compared to the mutant allele, the wild-type allele of the rs180040 polymorphism in POAG patients showed a 12% decrease in OR (OR = 0.88, 95%CI = 0.76- 1.00); also, the wild-type allele of rs1056827 showed a 23% decrease in OR of the incidence of POAG (OR = 0.77, 95%CI = 0.60-0.99). However, the latter result was controversial. Polymorphisms at rs1056836, rs10012, and rs1056837 were not correlated with the incidence of POAG (using any evaluation model). In conclusion, three of the tested SNPs in the CYP1B1 gene were correlated with POAG; however, the SNPs rs180040 and rs1056827 showed an association with risk of POAG. These results must be further validated with larger-scale evaluations.

  11. Role of 5-HT5A and 5-HT1B/1D receptors in the antinociception produced by ergotamine and valerenic acid in the rat formalin test.

    PubMed

    Vidal-Cantú, Guadalupe C; Jiménez-Hernández, Mildred; Rocha-González, Héctor I; Villalón, Carlos M; Granados-Soto, Vinicio; Muñoz-Islas, Enriqueta

    2016-06-15

    Sumatriptan, dihydroergotamine and methysergide inhibit 1% formalin-induced nociception by activation of peripheral 5-HT1B/1D receptors. This study set out to investigate the pharmacological profile of the antinociception produced by intrathecal and intraplantar administration of ergotamine (a 5-HT1B/1D and 5-HT5A/5B receptor agonist) and valerenic acid (a partial agonist at 5-HT5A receptors). Intraplantar injection of 1% formalin in the right hind paw resulted in spontaneous flinching behavior of the injected hindpaw of female Wistar rats. Intrathecal ergotamine (15nmol) or valerenic acid (1 nmol) blocked in a dose dependent manner formalin-induced nociception. The antinociception by intrathecal ergotamine (15nmol) or valerenic acid (1nmol) was partly or completely blocked by intrathecal administration of the antagonists: (i) methiothepin (non-selective 5-HT5A/5B; 0.01-0.1nmol); (ii) SB-699551 (selective 5-HT5A; up to 10nmol); (iii) anti-5-HT5A antibody; (iv) SB-224289 (selective 5-HT1B; 0.1-1nmol); or (v) BRL-15572 (selective 5-HT1D; 0.1-1nmol). Likewise, antinociception by intraplantar ergotamine (15nmol) and valerenic acid (10nmol) was: (i) partially blocked by methiothepin (1nmol), SB-699551 (10nmol) or SB-224289 (1nmol); and (ii) abolished by BRL-15572 (1nmol). The above doses of antagonists (which did not affect per se the formalin-induced nociception) were high enough to completely block their respective receptors. Our results suggest that ergotamine and valerenic acid produce antinociception via 5-HT5A and 5-HT1B/1D receptors located at both spinal and peripheral sites. This provides new evidence for understanding the modulation of nociceptive pathways in inflammatory pain.

  12. Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

    SciTech Connect

    Mahadevan, B.; Marston, C.P.; Luch, A.; Dashwood, W.M.; Brooks, E.; Pereira, C.; Doehmer, J.; Baird, W.M.

    2007-03-15

    A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealed that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.

  13. Protein kinase mediated upregulation of endothelin A, endothelin B and 5-hydroxytryptamine 1B/1D receptors during organ culture in rat basilar artery

    PubMed Central

    Hansen-Schwartz, Jacob; Svensson, Carl-Lennart; Xu, Cang-Bao; Edvinsson, Lars

    2002-01-01

    Organ culture has been shown to upregulate both endothelin (ET) and 5-hydroxytryptamine 1B/1D (5-HT1B/1D) receptors in rat cerebral arteries. The purpose of the present study was to investigate the involvement of protein kinases, especially protein kinases C (PKC) and A (PKA) in this process. The effect of inhibiting protein kinases during organ culture with staurosporine (unspecific protein kinase inhitor), RO 31-7549 (specific inhibitor of classical PKC's) and H 89 (specific inhibitor of PKA) was examined using in vitro pharmacological examination of cultured vessel segments with ET-1 (unspecific ETA and ETB agonist), S6c (specific ETB agonist) and 5-CT (5-HT1 agonist). Levels of mRNA coding for the ETA, ETB, 5-HT1B and 5-HT1D receptors were analysed using real-time RT–PCR. Classical PKC's are critically involved in the appearance of the ETB receptor; co-culture with RO 31-7549 abolished the contractile response (6.9±1.8%) and reduced the ETB receptor mRNA by 44±4% as compared to the cultured control. Correlation between decreased ETB receptor mRNA and abolished contractile function indicates upstream involvement of PKC. Inhibition of PKA generally had an enhancing effect on the induced changes giving rise to a 7–25% increase in Emax in response to ET-1, S6c and 5-CT as compared to the cultured control. Staurosporine inhibited the culture induced upregulation of the response of both the ETA and the 5-HT1B/1D receptors, but had no significant effect on the mRNA levels of these receptors. This lack of correlation indicates an additional downstream involvement of protein kinases. PMID:12183337

  14. Genotype-Phenotype Correlations in CYP1B1-Associated Primary Congenital Glaucoma Patients Representing Two Large Cohorts from India and Brazil

    PubMed Central

    de Melo, Mônica Barbosa; Mandal, Anil K.; Tavares, Ivan M.; Ali, Mohammed Hasnat; Kabra, Meha; de Vasconcellos, José Paulo Cabral; Senthil, Sirisha; Sallum, Juliana M. F.; Kaur, Inderjeet; Betinjane, Alberto J.; Moura, Christiane R.; Paula, Jayter S.; Costa, Karita A.; Sarfarazi, Mansoor; Paolera, Mauricio Della; Finzi, Simone; Ferraz, Victor E. F.; Costa, Vital P.; Belfort, Rubens; Chakrabarti, Subhabrata

    2015-01-01

    Background Primary congenital glaucoma (PCG), occurs due to the developmental defects in the trabecular meshwork and anterior chamber angle in children. PCG exhibits genetic heterogeneity and the CYP1B1 gene has been widely implicated worldwide. Despite the diverse mutation spectra, the clinical implications of these mutations are yet unclear. The present study attempted to delineate the clinical profile of PCG in the background of CYP1B1 mutations from a large cohort of 901 subjects from India (n=601) and Brazil (n=300). Methods Genotype-phenotype correlations was undertaken on clinically well characterized PCG cases from India (n=301) and Brazil (n=150) to assess the contributions of CYP1B1 mutation on a set of demographic and clinical parameters. The demographic (gender, and history of consanguinity) and quantitative clinical (presenting intraocular pressure [IOP] and corneal diameter [CD]) parameters were considered as binary and continuous variables, respectively, for PCG patients in the background of the overall mutation spectra and also with respect to the prevalent mutations in India (R368H) and Brazil (4340delG). All these variables were fitted in a multivariate logistic regression model using the Akaike Information Criterion (AIC) to estimate the adjusted odds ratio (OR) using the R software (version 2.14.1). Results The overall mutation spectrum were similar across the Indian and Brazilian PCG cases, despite significantly higher number of homozygous mutations in the former (p=0.024) and compound heterozygous mutations in the later (p=0.012). A wide allelic heterogeneity was observed and only 6 mutations were infrequently shared between these two populations. The adjusted ORs for the binary (demographic) and continuous (clinical) variables did not indicate any susceptibility to the observed mutations (p>0.05). Conclusions The present study demonstrated a lack of genotype-phenotype correlation of the demographic and clinical traits to CYP1B1 mutations in

  15. Changes in 2-hydroxyestrone and 16alpha-hydroxyestrone metabolism with flaxseed consumption: modification by COMT and CYP1B1 genotype.

    PubMed

    McCann, Susan E; Wactawski-Wende, Jean; Kufel, Kari; Olson, James; Ovando, Bladimir; Kadlubar, Susan Nowell; Davis, Warren; Carter, Lisa; Muti, Paola; Shields, Peter G; Freudenheim, Jo L

    2007-02-01

    Consumption of the phytoestrogen lignans, structurally similar to estrogen, has been associated with alterations in gene expression and estrogen metabolism. Furthermore, lignan consumption, subsequent changes in metabolizing enzyme expression, and genetic variability in these enzymes may alter estrogen metabolism and modify disease risk. Therefore, we investigated the effect of flaxseed on hydroxyestrone metabolite excretion by catechol-O-methyltransferase (COMT) and cytochrome P450 1B1 (CYP1B1) genotype. We conducted an intervention among 132 healthy, postmenopausal women, ages 46 to 75 years. Participants consumed 10 g ground flaxseed daily for 7 consecutive days. Blood and urine samples were collected at baseline and after the 7-day intervention. COMT Val(158)Met and CYP1B1 Leu(432)Val genotypes were determined using PCR-RFLP methods. Urinary 2-hydroxyestrone (2OHE1) and 16alpha-hydroxyestrone (16OHE1) were quantified by ELISA assay. The effect of genotype on intervention-related changes in estrogen metabolites was assessed with the Kruskal-Wallis test. Compared with baseline levels, postintervention levels of urinary 2OHE1 (ng/mg creatinine; mean +/- SD, 16.1 +/- 10.6 versus 9.3 +/- 6.9, postintervention and baseline, respectively; P < 0.01) and 2OHE1/16OHE1 ratios (mean +/- SD, 2.73 +/- 1.47 versus 1.54 +/- 0.75, postintervention and baseline, respectively; P < 0.01) were significantly higher. The change in 2OHE1/16OHE1 increased with increasing numbers of variant alleles for COMT (mean change: Val/Val, 0.90; Val/Met, 1.15; and Met/Met, 1.50; P = 0.17, Kruskal-Wallis) and especially CYP1B1 (mean change: Leu/Leu, 0.89; Leu/Val, 1.32; and Val/Val, 1.51; P = 0.04, Kruskal-Wallis). Our findings suggest that variation in hormone-related genes may modify the effect of dietary lignan exposures on estrogen metabolism.

  16. [Genetic variants of CYP1B1 and WDR36 in the patients with primary congenital glaucoma and primary open angle glaucoma from Saint-Petersburg].

    PubMed

    Motushchuk, A E; Komarova, T Iu; Grudinina, N A; Rakhmanov, V V; Mandel'shtam, M Iu; Astakhov, Iu S; Vasil'ev, V B

    2009-12-01

    In 32 patients with primary congenital glaucoma (PCG), a search for mutations in the myocilin (MYOC), cytochrome P450B1 (CYP1B1), and WDR36 genes was performed. The Q368X mutation in myocilin gene, typical of the patients with adult-onset primary open-angle glaucoma (POAG), was not detected in the PCG patients. Screening of the CYP1B1 introns 2 and 3 for the presence of mutations in PCG patients revealed only six DNA polymorphisms, including IVS1-12ntT>C (g.3793 T>C), A119S (g.4160 G>T; GCC>TCC), G188G (g.4369 C>A; GGC>GGA), L432V (G.8131 C>G; CTG>GTG), D449D (g.8184 C>T; GAC>GAT), and N453S (g.8195 A>G; AAC>AGC) (nucleotide numbering is given in accordance with the GenBank sequence U56438). In the groups of PCG patients and donors without eye diseases, the frequencies of these variants were not statistically significantly different, pointing to the neutrality of these polymorphisms. Furthermore, the CYP1B1 polymorphism L432V, considered to be associated with POAG in some world populations, was not associated with this disease in the patients from St. Petersburg. DNA collections obtained from the POAG and PCG patients and from the control group were tested for the carriage of the worldwide distributed mutations of the WRD36 gene, D658G, R529Q, A449T, and N355S. D658G variant was found with equally low frequencies in the groups of POAG and PCG patients, as well as in the control group. Mutations A449T and R529Q were found only once each, while mutation N355S was not detected in any of the groups examined. Our results indicate that the WDR36 variants make no substantial contribution to the development of POAG and PCG in the patients from St. Petersburg and represent normal DNA polymorphism. It is likely that in most of the PCG patients from the population examined the disease is not associated with the CYP1B1 gene defects.

  17. CYP1A1 and CYP1B1 polymorphisms as modifying factors in patients with pneumoconiosis and occupationally related tumours: A pilot study.

    PubMed

    Schneider, Joachim; Bernges, Ulrike

    2009-01-01

    CYP1A1 and CYP1B1 are involved in the metabolism of carcinogens. The effect of CYP1A1 and CYP1B1 polymorphisms as genetic modifiers of risk was investigated in individuals with asbestos, silica dust or ionizing radiation-induced occupational tumours compared to exposed non-cancer subjects suffering from pneumoconiosis, particularly in relation to tobacco smoking. CYP1A1 T6235C, CYP1A1 A4889G and CYP1B1 codon 432 polymorphisms were determined by real-time PCR analysis in patients with asbestos-related lung cancer (n=39), patients with diffuse malignant mesotheliomas (n=19), lung cancer in silicosis patients (n=7), uranium miners with lung cancer (UMLC) (n=40), patients with asbestosis (n=181), and silicosis patients (n=204). The results were compared to those from a healthy unexposed control group (n=50) not exposed to carcinogenic (or fibrogenic) agents in the workplace. An additional healthy control group (n=134) comprised smokers and ex-smokers. Allele frequencies were within the range described for Caucasians. Multivariate analysis revealed that patients with occupational diseases with the susceptible CYP1A1 T6235C genotype had a calculated risk ranging from OR=0.5 (95% CI 0.18-1.36) for UMLC to OR=1.23 (95% CI 0.39-4.05) for uranium miners with silicosis. The risk for patients with the susceptible CYP1A1 A4889G allele was calculated as being between OR=0.39 (95% CI 0.10-1.54) for mesothelioma patients and OR=1.54 (95% CI 0.49-4.89) for UMLC. CYP1B1 Val432Leu polymorphisms were associated with a risk of OR=0.56 (95% CI 0.2-1.55) for UMLC and OR=1.52 (95% CI 0.68-3.39) for asbestos-exposed lung cancer patients. By analyzing the interaction between tobacco smoking, type of exposure to carcinogens and the genotypes, it was determined that smoking and the presence of the susceptible genotypes did not have a combined effect. In this pilot study, the analyzed polymorphism had no consistent modifying effect on pneumoconiosis or occupationally related tumours.

  18. Effects of SNPs (CYP1B1*2 G355T, CYP1B1*3 C4326G, and CYP2E1*5 G-1293C), Smoking, and Drinking on Susceptibility to Laryngeal Cancer among Han Chinese

    PubMed Central

    Jin, Jianhua; Lin, Faming; Liao, Shiyu; Bao, Qiyu; Ni, Liyan

    2014-01-01

    Purpose This study was conducted to explore the effects of genetic polymorphisms (CYP1B1*2 G355T, CYP1B1*3 C4326G, and CYP2E1*5 G-1293C) and environmental factors (smoking and drinking) on susceptibility to laryngeal cancer in a Han Chinese study group. Methods This case-control study included 552 Han Chinese patients diagnosed with laryngeal cancer and 666 healthy control subjects of the same ethnicity, similar age, and gender. Genetic polymorphisms were examined using multi-PCR and Matrix Assisted Laser Desorption Ionization - Time of Flight (MALDI-TOF MS) methodology. The association of these genetic and environmental factors with susceptibility to laryngeal cancer was evaluated using a statistical approach. Results The frequencies of all three polymorphisms in the patient cohort were significantly different from those in the control cohort. Compared to the control cohort, carriers of variant alleles of CYP1B1*2 355T and CYP2E1*5 -1293C showed a higher risk for developing laryngeal cancer (for CYP1B1*2 355T, adjusted OR = 2.657, P <0.001; for CYP2E1*5 -1293C, adjusted OR = 1.938, P <0.001), while carriers of mutation allele CYP1B1*3 4326G showed a lower risk (adjusted OR = 0.562, P <0.001). Joint effects of these polymorphisms were observed. When compared to haplotype G355C4326G−1293, haplotypes T355C4326G−1293 (adjusted OR = 1.809, P <0.001), G355C4326C−1293 (adjusted OR = 1.644, P = 0.044), and T355C4326C−1293 (adjusted OR = 3.104, P <0.001) were associated with a significantly higher laryngeal cancer risk. The adjusted ORs for non-smokers, non-drinkers, smokers, and drinkers with the GT/TT genotype at CYP1B1*2 G355T were 2.190 (P = 0.006), 2.008 (P = 0.001), 5.875 (P <0.001), and 4.518 (P <0.001), respectively. Conclusions CYP1B1*2 355T and CYP2E1*5 -1293C are associated with an increased laryngeal cancer risk, while CYP1B1*3 4326G is associated with a decreased risk. These polymorphisms showed joint effects on

  19. Association of CYP1A1, CYP1B1 and CYP17 gene polymorphisms and organochlorine pesticides with benign prostatic hyperplasia.

    PubMed

    Kumar, Vivek; Banerjee, Basu Dev; Datta, Sudip Kumar; Yadav, Chandra Shekhar; Singh, Satyender; Ahmed, Rafat Sultana; Gupta, Sanjay

    2014-08-01

    It is well established that steroidal hormones (testosterone and estrogen) increase benign prostatic hyperplasia (BPH) risk. Cytochrome P450 (CYP) enzymes especially CYP1A1, CYP1B1 and CYP17 metabolize these hormones. Apart from that, several endocrine disrupting organochlorine pesticides (OCPs) are reported to mimic the activity of these steroidal hormones. Therefore, functional polymorphisms in these genes and exposure to such pesticides may increase BPH risk further. Our study included 100 newly diagnosed BPH subjects and 100 age-matched healthy male controls. CYP1A1, CYP1B1 and CYP17 polymorphisms were studied using PCR-RFLP and allele-specific PCR method. OCP levels in blood were analyzed by gas chromatography (GC). Levels of p,p'-DDE and endosulfan α were found to be significantly higher amongst BPH subjects as compared to controls (p-values=0.001 and 0.03 respectively) and CYP17 polymorphism was observed to be significantly associated with BPH subjects as compared to controls (p-values=0.03), indicating that these factors may be important risk factors for BPH. However, further studies are required before unequivocal conclusion.

  20. Amino Acid Residues in the Putative Transmembrane Domain 11 of Human Organic Anion Transporting Polypeptide 1B1 Dictate Transporter Substrate Binding, Stability, and Trafficking.

    PubMed

    Hong, Weifang; Wu, Zhixuan; Fang, Zihui; Huang, Jiujiu; Huang, Hong; Hong, Mei

    2015-12-07

    Organic anion transporting polypeptides (OATPs, gene symbol SLCO) are membrane proteins that mediate the sodium-independent transport of a wide range of endogenous and exogenous compounds. Due to their broad substrate specificity, wide tissue distribution, and involvement in drug-drug interactions, OATPs have been considered as key players in drug absorption, distribution, and excretion. Transmembrane domains (TMs) are crucial structural features involved in proper functions of many transporters. According to computer-based modeling and previous studies of our laboratory and others, TM11 of OATP1B1 may face the substrate interaction pocket and thus play an important role in the transport function of the protein. Alanine-scanning of the transmembrane domain identified seven critical amino acid residues within the region. Further analysis revealed that alanine substitution of these residues resulted in reduced protein stability, which led to significantly decreased protein expression on the plasma membrane. In addition, all mutants exhibited an altered Km for ES uptake (either high affinity or low affinity component, or both), though Km for taurocholate transport only changed in R580A, G584A, and F591A. These results suggested that critical residues in TM11 not only affect protein stability of the transporter, but its interaction with substrates as well. The identification of seven essential residues out of 21 TM amino acids highlighted the importance of this transmembrane domain in the proper function of OATP1B1.

  1. One-pot synthesis of new triazole--Imidazo[2,1-b][1,3,4]thiadiazole hybrids via click chemistry and evaluation of their antitubercular activity.

    PubMed

    Ramprasad, Jurupula; Nayak, Nagabhushana; Dalimba, Udayakumar; Yogeeswari, Perumal; Sriram, Dharmarajan

    2015-10-01

    A new series of triazole-imidazo[2,1-b][1,3,4]thiadiazole hybrids (6a-s, 7a) were designed by a molecular hybridisation approach and the target molecules were synthesized via one pot click chemistry protocol. All the intermediates and final molecules were characterised using spectral methods and one of the target compounds (6c) was analysed by the single crystal XRD study. The derivatives were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain. Two compounds, 6f and 6n, demonstrated significant growth inhibitory activity against the bacterial strain with a MIC of 3.125 μg/mL. The presence of chloro substituent on the imidazo[2,1-b][1,3,4]thiadiazole ring and ethyl, benzyl or cyanomethylene groups on the 1,2,3-triazole ring enhance the inhibition activity of the molecules. The active compounds are not toxic to a normal cell line which signifies the lack of general cellular toxicity of these compounds.

  2. Primary congenital glaucoma caused by the homozygous F261L CYP1B1 mutation and paternal isodisomy of chromosome 2.

    PubMed

    López-Garrido, M-P; Campos-Mollo, E; Harto, M-A; Escribano, J

    2009-12-01

    Primary congenital glaucoma (PCG), a rare, severe and blinding disease, usually results from mutations in the CYP1B1 gene located in chromosome 2p22.2. Uniparental isodisomy (UPID) is also a rare condition in which a diploid offspring carries two identical copies of a single parental chromosome. By DNA sequence analysis, we found that a proband (female newborn) affected by PCG was homozygous for the null-allele F261L of the CYP1B1 gene. Her father was a heterozygous carrier for this mutation, and unexpectedly her mother carried only the G168D mutation in the heterozygous state. Segregation analysis of eight microsatellite markers which spanned the two arms of chromosome 2 was consistent with paternal isodisomy for this chromosome in the proband. To the best of our knowledge, this is the first reported case of UPID resulting in PCG and the fifth reported case of paternal UPID for chromosome 2. In addition, the absence of a clinical phenotype other than PCG confirms previous observations of there being no paternally imprinted genes in chromosome 2 that have major phenotypic effects. These results, along with previous reports, also suggest that UPID may play a relevant role in recessive diseases linked to chromosome 2.

  3. Mutations in CYP1B1, the gene for cytochrome P4501B1, are the predominant cause of primary congenital glaucoma in Saudi Arabia.

    PubMed Central

    Bejjani, B A; Lewis, R A; Tomey, K F; Anderson, K L; Dueker, D K; Jabak, M; Astle, W F; Otterud, B; Leppert, M; Lupski, J R

    1998-01-01

    The autosomal recessive disorder primary congenital glaucoma (PCG) is caused by unknown developmental defect(s) of the trabecular meshwork and anterior chamber angle of the eye. Homozygosity mapping with a DNA pooling strategy in three large consanguineous Saudi PCG families identified the GLC3A locus on chromosome 2p21 in a region tightly linked to PCG in another population. Formal linkage analysis in 25 Saudi PCG families confirmed both significant linkage to polymorphic markers in this region and incomplete penetrance, but it showed no evidence of genetic heterogeneity. For these 25 families, the maximum combined two-point LOD score was 15.76 at a recombination fraction of .021, with the polymorphic marker D2S177. Both haplotype analysis and homozygosity mapping in these families localized GLC3A to a 5-cM critical interval delineated by markers D2S2186 and D2S1356. Sequence analysis of the coding exons for cytochrome P4501B1 (CYP1B1) in these 25 families revealed three distinctive mutations that segregate with the phenotype in 24 families. Additional clinical and molecular data on some mildly affected relatives showed variable expressivity of PCG in this population. These results should stimulate a study of the genetic and environmental events that modify the effects of CYP1B1 mutations in ocular development. Furthermore, the small number of PCG mutations identified in this Saudi population makes both neonatal and population screening attractive public health measures. PMID:9463332

  4. Whole genome expression profiling of blood cells in ovarian cancer patients -prognostic impact of the CYP1B1, MTSS1, NCALD, and NOP14.

    PubMed

    Isaksson, Helena S; Sorbe, Bengt; Nilsson, Torbjörn K

    2014-06-30

    Ovarian cancer patients with different tumor stages and cell differentiation might be distinguished from each other by gene expression profiles in whole blood cell mRNA by the Affymetrix Human Gene 1.0 ST Array. We also examined if there is any association with other clinical variables, response to therapy, and residual tumor burden after surgery. Patients were divided into two groups, one with poor prognosis, advanced stage and poorly differentiated tumors (n = 22), and one group with good prognosis, early stage and well- to medium differentiated tumors (n = 11). Six genes were found to be differentially expressed: the PDIA3, LYAR, NOP14, NCALD and MTSS1 genes were down-regulated and the CYP1B1 gene expression was up-regulated in the poor prognosis group, all with p value <0.05, adjusted for mass comparison. In survival analyses, CYP1B1, MTSS1, NCALD and NOP14 remained significantly different (p<0.05). Patient groups did not differ in any transcript related to acute phase or immune responses. This minimal gene expression signature of prognostic ovarian cancer-related genes opens up an avenue for more practicable monitoring of ovarian cancer patients by simple peripheral blood tests, which may evolve into a tool to guide selection of curative and postoperative supportive therapies.

  5. Triclosan activates aryl hydrocarbon receptor (AhR)-dependent apoptosis and affects Cyp1a1 and Cyp1b1 expression in mouse neocortical neurons.

    PubMed

    Szychowski, Konrad A; Wnuk, Agnieszka; Kajta, Małgorzata; Wójtowicz, Anna K

    2016-11-01

    Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitizing products, such as soaps, toothpastes, and hair products. A number of studies have revealed the presence of TCS in human tissues, such as fat, liver and brain, in addition to blood and breast milk. The aim of the present study was to investigate the impact of TCS on AhR and Cyp1a1/Cyp1b1 signaling in mouse neocortical neurons in primary cultures. In addition to the use of selective ligands and siRNAs, expression levels of mRNA and proteins as well as caspase-3 activity, reactive oxygen species (ROS) formation, and lactate dehydrogenase (LDH) release have been measured. We also studied the involvement of the AhR in TCS-induced LDH release and caspase-3 activation as well as the effect of TCS on ROS generation. Cultures of neocortical neurons were prepared from Swiss mouse embryos on day 15/16 of gestation. The cells were cultured in phenol red-free Neurobasal medium with B27 and glutamine, and the neurons were exposed to 1 and 10µM TCS. Our experiments showed that the expression of AhR and Cyp1a1 mRNA decreased in cells exposed to 10µM TCS for 3 or 6h. In the case of Cyp1b1, mRNA expression remained unchanged compared with the control group following 3h of exposure to TCS, but after 6h, the mRNA expression of Cyp1b1 was decreased. Our results confirmed that the AhR is involved in the TCS mechanism of action, and our data demonstrated that after the cells were transfected with AhR siRNA, the cytotoxic and pro-apoptotic properties of TCS were decreased. The decrease in Cyp1a1 mRNA and protein expression levels accompanied by a decrease in its activity. The stimulation of Cyp1a1 activity produced by the application of an AhR agonist (βNF) was attenuated by TCS, whereas the addition of AhR antagonist (αNF) reversed the inhibitory effects of TCS. In our experiments, TCS diminished Cyp1b1 mRNA and enhanced its protein expression. In case of Cyp1a1 we observed

  6. CYP2D6 and CYP2A6 biotransform dietary tyrosol into hydroxytyrosol.

    PubMed

    Rodríguez-Morató, Jose; Robledo, Patricia; Tanner, Julie-Anne; Boronat, Anna; Pérez-Mañá, Clara; Oliver Chen, C-Y; Tyndale, Rachel F; de la Torre, Rafael

    2017-02-15

    The dietary phenol tyrosol has been reported to be endogenously transformed into hydroxytyrosol, a potent antioxidant with multiple health benefits. In this work, we evaluated whether tyrosine hydroxylase (TH) and cytochrome P450s (CYPs) catalyzed this process. To assess TH involvement, Wistar rats were treated with α-methyl-L-tyrosine and tyrosol. Tyrosol was converted into hydroxytyrosol whilst α-methyl-L-tyrosine did not inhibit the biotransformation. The role of CYP was assessed in human liver microsomes (HLM) and tyrosol-to-hydroxytyrosol conversion was observed. Screening with selective enzymatic CYP inhibitors identified CYP2A6 as the major isoform involved in this process. Studies with baculosomes further demonstrated that CYP2D6 and CYP3A4 could transform tyrosol into hydroxytyrosol. Experiments using human genotyped livers showed an interindividual variability in hydroxytyrosol formation and supported findings that CYP2D6 and CYP2A6 mediated this reaction. The dietary health benefits of tyrosol-containing foods remain to be evaluated in light of CYP pharmacogenetics.

  7. Polymorphisms in CYP1B1, CYP3A5, GSTT1, and SULT1A1 Are Associated with Early Age Acute Leukemia.

    PubMed

    Lopes, Bruno Almeida; Emerenciano, Mariana; Gonçalves, Bruno Alves Aguiar; Vieira, Tállita Meciany; Rossini, Ana; Pombo-de-Oliveira, Maria S

    2015-01-01

    Based on observational studies, early age leukemia (EAL) was associated with maternal hormone exposure during pregnancy. We studied the association between genetic polymorphisms of estrogen metabolism and EAL. Using data from the Brazilian Collaborative Study Group of Infant Acute Leukemia (2000-2012), 350 cases and 404 age-matched controls and 134 mothers of cases and controls were genotyped to explore polymorphisms in genes of the estrogen metabolism pathway: CYP1B1 (c.1294C>G, rs1056836), CYP3A4 (c.-392A>G, rs2740574), CYP3A5 (c.219-237G>A, rs776746), GSTM1/GSTT1 deletions, and SULT1A1 (c.638G>A, rs9282861; and c.667A>G, rs1801030). Logistic regression was used to calculate the odds ratios (OR) with 95% confidence intervals (CIs), and unconditional logistic regression was used to estimate adjusted odds ratios (aORs) by ethnicity. Because of multiple testing, p values < 0.01 were significant after Bonferroni correction. SULT1A1 (c.638G>A) was associated to infant acute lymphoblastic leukemia and acute myeloid leukemia (AML) risk in males (additive model: aOR = 0.52; 95% CI: 0.29-0.95, p = 0.03; dominant model: aOR = 2.18; 95% CI: 1.17-4.05, p = 0.01, respectively). CYP1B1 polymorphism was associated with a decreased risk of AML either for non-white or female children (additive model: OR = 0.24; 95% CI: 0.08-0.76, p < 0.01; additive model: aOR = 0.27; 95% CI: 0.08-0.89, p = 0.03, respectively). Since polymorphisms of Cytochrome P450 genes presented gender-specific risk associations, we also investigated their expression. CYP1B1 was not expressed in 57.1% of EAL cases, and its expression varied by genotype, gender, and leukemia subtype. Maternal-fetal GSTT1 null genotype was associated with risk of EAL. This study shows that polymorphisms in genes of estrogen metabolism confer genetic susceptibility to EAL, mainly in males, and maternal susceptibility genes modify the risk for developing EAL in newborns.

  8. The Val432Leu polymorphism of the CYP1B1 gene is associated with differences in estrogen metabolism and bone density.

    PubMed

    Napoli, Nicola; Rini, Giovam Battista; Serber, Daniel; Giri, Tusar; Yarramaneni, Jayasree; Bucchieri, Salvatore; Camarda, Lawrence; Di Fede, Gaetana; Camarda, Marcello Rosolino; Jain, Sudahansu; Mumm, Steven; Armamento-Villareal, Reina

    2009-03-01

    Polymorphisms of the CYP450 genes that encode for the enzymes that metabolize estrogen are linked to hormone-related cancers. We investigated the impact of two polymorphisms of the CYP1B1 gene previously reported to be associated with hormone-related disorders on estrogen metabolism and bone mineral density (BMD), another hormone-dependent condition, in women from different ethnic backgrounds. Four hundred sixty-eight postmenopausal Caucasian women, 220 from St. Louis, MO, USA (mean age=63.5+/-0.53 years) and 248 from Palermo, Italy (mean age=72.9+/-0.44 years) participated in the study. Measurements of urinary estrogen metabolites by enzyme-linked immunoassay, serum estradiol by ultrasensitive radioimmnunoassay, and serum sex hormone-binding globulin by immunoradiometric assay were performed only in the American women, while BMD by dual energy X-ray absorptiometry and genotyping by pyrosequencing were performed in both American and Italian women. Differences in the levels of metabolites, free estradiol index and BMD were analyzed by analysis of covariance. Analysis among the American participants for the Valine432Leucine polymorphism showed that, compared to women with the Val/Val genotype, women with the Leu allele (Val/Leu and Leu/Leu) had significantly higher log-transformed values of total urinary estrogen metabolite (ng/mg-creatinine) levels (1.23+/-0.04, 1.35+/-0.02, and 1.34+/-0.03; p=0.03), and significantly lower BMD (gm/cm(2)) in the lumbar spine (1.009+/-0.02, 0.955+/-0.01 and 0.931+/-0.02; p=0.03) and the femoral neck (0.748+/-0.02, 0.717+/-0.01 and 0.693+/-001, p=0.03) for the Val/Val, Val/Leu and Leu/Leu genotypes respectively. There were no significant differences in the urinary metabolites and BMD in the different genotypes for the Alanine119Serine polymorphism among the American women. Meanwhile, a separate analysis among the Italian women revealed no significant differences in BMD among the different genotypes for the two polymorphisms

  9. Polymorphisms in CYP1B1, CYP3A5, GSTT1, and SULT1A1 Are Associated with Early Age Acute Leukemia

    PubMed Central

    Lopes, Bruno Almeida; Emerenciano, Mariana; Gonçalves, Bruno Alves Aguiar; Vieira, Tállita Meciany; Rossini, Ana; Pombo-de-Oliveira, Maria S.

    2015-01-01

    Based on observational studies, early age leukemia (EAL) was associated with maternal hormone exposure during pregnancy. We studied the association between genetic polymorphisms of estrogen metabolism and EAL. Using data from the Brazilian Collaborative Study Group of Infant Acute Leukemia (2000–2012), 350 cases and 404 age-matched controls and 134 mothers of cases and controls were genotyped to explore polymorphisms in genes of the estrogen metabolism pathway: CYP1B1 (c.1294C>G, rs1056836), CYP3A4 (c.-392A>G, rs2740574), CYP3A5 (c.219-237G>A, rs776746), GSTM1/GSTT1 deletions, and SULT1A1 (c.638G>A, rs9282861; and c.667A>G, rs1801030). Logistic regression was used to calculate the odds ratios (OR) with 95% confidence intervals (CIs), and unconditional logistic regression was used to estimate adjusted odds ratios (aORs) by ethnicity. Because of multiple testing, p values < 0.01 were significant after Bonferroni correction. SULT1A1 (c.638G>A) was associated to infant acute lymphoblastic leukemia and acute myeloid leukemia (AML) risk in males (additive model: aOR = 0.52; 95% CI: 0.29–0.95, p = 0.03; dominant model: aOR = 2.18; 95% CI: 1.17–4.05, p = 0.01, respectively). CYP1B1 polymorphism was associated with a decreased risk of AML either for non-white or female children (additive model: OR = 0.24; 95% CI: 0.08–0.76, p < 0.01; additive model: aOR = 0.27; 95% CI: 0.08–0.89, p = 0.03, respectively). Since polymorphisms of Cytochrome P450 genes presented gender-specific risk associations, we also investigated their expression. CYP1B1 was not expressed in 57.1% of EAL cases, and its expression varied by genotype, gender, and leukemia subtype. Maternal-fetal GSTT1 null genotype was associated with risk of EAL. This study shows that polymorphisms in genes of estrogen metabolism confer genetic susceptibility to EAL, mainly in males, and maternal susceptibility genes modify the risk for developing EAL in newborns. PMID:25992585

  10. Evidence for 5-HT1B/1D and 5-HT2A receptors mediating constriction of the canine internal carotid circulation

    PubMed Central

    Centurión, David; Ortiz, Mario I; Sánchez-López, Araceli; De Vries, Peter; Saxena, Pramod R; Villalón, Carlos M

    2001-01-01

    The present study has investigated the preliminary pharmacological profile of the receptors mediating vasoconstriction to 5-hydroxytryptamine (5-HT) in the internal carotid bed of vagosympathectomised dogs. One minute intracarotid infusions of the agonists 5-HT (0.1–10 μg min−1), sumatriptan (0.3–10 μg min−1; 5-HT1B/1D), 5-methoxytryptamine (1–100 μg min−1; 5-HT1, 5-HT2, 5-HT4, 5-ht6 and 5-HT7) or DOI (0.31–10 μg min−1; 5-HT2), but not 5-carboxamidotryptamine (0.01–0.3 μg min−1; 5-HT1, 5-ht5A and 5-HT7), 1-(m-chlorophenyl)-biguanide (mCPBG; 1–1000 μg min−1; 5-HT3) or cisapride (1–1000 μg min−1; 5-HT4), resulted in dose-dependent decreases in internal carotid blood flow, without changing blood pressure or heart rate. The vasoconstrictor responses to 5-HT, which remained unaffected after saline, were resistant to blockade by i.v. administration of the antagonists ritanserin (100 μg kg−1; 5-HT2A/2B/2C) in combination with tropisetron (3000 μg kg−1; 5-HT3/4) or the cyclo-oxygenase inhibitor, indomethacin (5000 μg kg−1), but were abolished by the 5-HT1B/1D receptor antagonist, GR127935 (30 μg kg−1). Interestingly, after administration of GR127935, the subsequent administration of ritanserin unmasked a dose-dependent vasodilator component. GR127935 or saline did not practically modify the vasoconstrictor effects of 5-MeO-T. In animals receiving GR127935, the subsequent administration of ritanserin abolished the vasoconstrictor responses to 5-MeO-T unmasking a dose-dependent vasodilator component. The vasoconstriction induced by sumatriptan was antagonized by GR127935, but not by ritanserin. Furthermore, ritanserin (100 μg kg−1) or ketanserin (100 μg kg−1; 5-HT2A), but not GR127935, abolished DOI-induced vasoconstrictor responses. The above results suggest that 5-HT-induced internal carotid vasoconstriction is predominantly mediated by 5-HT1B/1D and 5-HT2A receptors

  11. Inactivation of CYP2A6 by the Dietary Phenylpropanoid trans-Cinnamic Aldehyde (Cinnamaldehyde) and Estimation of Interactions with Nicotine and Letrozole.

    PubMed

    Chan, Jeannine; Oshiro, Tyler; Thomas, Sarah; Higa, Allyson; Black, Stephen; Todorovic, Aleksandar; Elbarbry, Fawzy; Harrelson, John P

    2016-04-01

    Human exposure to trans-cinnamic aldehyde [t-CA; cinnamaldehyde; cinnamal; (E)-3-phenylprop-2-enal] is common through diet and through the use of cinnamon powder for diabetes and to provide flavor and scent in commercial products. We evaluated the likelihood of t-CA to influence metabolism by inhibition of P450 enzymes. IC50 values from recombinant enzymes indicated that an interaction is most probable for CYP2A6 (IC50 = 6.1 µM). t-CA was 10.5-fold more selective for human CYP2A6 than for CYP2E1; IC50 values for P450s 1A2, 2B6, 2C9, 2C19, 2D6, and 3A4 were 15.8-fold higher or more. t-CA is a type I ligand for CYP2A6 (KS = 14.9 µM). Inhibition of CYP2A6 by t-CA was metabolism-dependent; inhibition required NADPH and increased with time. Glutathione lessened the extent of inhibition modestly and statistically significantly. The carbon monoxide binding spectrum was dramatically diminished after exposure to NADPH and t-CA, suggesting degradation of the heme or CYP2A6 apoprotein. Using a static model and mechanism-based inhibition parameters (K(I) = 18.0 µM; k(inact) = 0.056 minute(-1)), changes in the area under the concentration-time curve (AUC) for nicotine and letrozole were predicted in the presence of t-CA (0.1 and 1 µM). The AUC fold-change ranged from 1.1 to 3.6. In summary, t-CA is a potential source of pharmacokinetic variability for CYP2A6 substrates due to metabolism-dependent inhibition, especially in scenarios when exposure to t-CA is elevated due to high dietary exposure, or when cinnamon is used as a treatment of specific disease states (e.g., diabetes).

  12. Inactivation of CYP2A6 by the Dietary Phenylpropanoid trans-Cinnamic Aldehyde (Cinnamaldehyde) and Estimation of Interactions with Nicotine and Letrozole

    PubMed Central

    Chan, Jeannine; Oshiro, Tyler; Thomas, Sarah; Higa, Allyson; Black, Stephen; Todorovic, Aleksandar; Elbarbry, Fawzy

    2016-01-01

    Human exposure to trans-cinnamic aldehyde [t-CA; cinnamaldehyde; cinnamal; (E)-3-phenylprop-2-enal] is common through diet and through the use of cinnamon powder for diabetes and to provide flavor and scent in commercial products. We evaluated the likelihood of t-CA to influence metabolism by inhibition of P450 enzymes. IC50 values from recombinant enzymes indicated that an interaction is most probable for CYP2A6 (IC50 = 6.1 µM). t-CA was 10.5-fold more selective for human CYP2A6 than for CYP2E1; IC50 values for P450s 1A2, 2B6, 2C9, 2C19, 2D6, and 3A4 were 15.8-fold higher or more. t-CA is a type I ligand for CYP2A6 (KS = 14.9 µM). Inhibition of CYP2A6 by t-CA was metabolism-dependent; inhibition required NADPH and increased with time. Glutathione lessened the extent of inhibition modestly and statistically significantly. The carbon monoxide binding spectrum was dramatically diminished after exposure to NADPH and t-CA, suggesting degradation of the heme or CYP2A6 apoprotein. Using a static model and mechanism-based inhibition parameters (KI = 18.0 µM; kinact = 0.056 minute−1), changes in the area under the concentration-time curve (AUC) for nicotine and letrozole were predicted in the presence of t-CA (0.1 and 1 µM). The AUC fold-change ranged from 1.1 to 3.6. In summary, t-CA is a potential source of pharmacokinetic variability for CYP2A6 substrates due to metabolism-dependent inhibition, especially in scenarios when exposure to t-CA is elevated due to high dietary exposure, or when cinnamon is used as a treatment of specific disease states (e.g., diabetes). PMID:26851241

  13. From thiourea to bicyclic structures: an original route to imidazo[2,1-b]thiazoles, 5H-thiazolo[3,2-a]pyrimidines, 7H-imidazo[2,1-b][1,3]thiazines, and 2H,6H-pyrimido[2,1-b][1,3]thiazines.

    PubMed

    Landreau, Cyrille; Deniaud, David; Meslin, Jean Claude

    2003-06-13

    We report an example of an efficient regioselective synthesis of biheterocyclic compounds using thiourea as starting material. In fact, N,N'-bis(dimethylaminomethylene)thiourea (1), easily prepared by double condensation of N,N-dimethylformamide dimethyl acetal with thiourea, can be reacted with haloketones or acrylic dienophiles to give thiazolic (2) and thiazinic (3) diazadienes, respectively, themselves undergoing cyclization reactions to yield imidazo[2,1-b]thiazoles, 5H-thiazolo[3,2-a]pyrimidines, 7H-imidazo[2,1-b][1,3]thiazines, and 2H,6H-pyrimido[2,1-b][1,3]thiazines without any regioisomeric ambiguity. This straightforward route represents an original and unambiguously regioselective pathway to these valuable heterocycles.

  14. [Homozygous E387K (1159G>A) mutation of the CYP1B1 gene in a Roma boy affected with primary congenital glaucoma. Case report].

    PubMed

    Vogt, Gábor; Kádasi, Ľudevit Lajos; Czeizel, Endre

    2014-08-17

    Primary congenital glaucoma was diagnosed in a son (born in 2009) of a healthy, non-consanguineous Roma couple. This couple terminated their next two pregnancies because of the 25% recurrence risk of this autosomal recessive ophthalmological abnormality. Molecular genetic analysis showed the homozygote E387K mutation of the CYP1B1 gene in the proband and the presence of this gene mutation in heterozygous form in both parents. This gene mutation is characteristic for Slovakian Roma population. There are two objectives of this case report. On one hand this finding indicates the genetic relationship of Slovakian and Hungarian Romas. On the other hand, the couple plans to have further pregnancies, and prenatal genetic test may help to assess the possible recurrence risk of this hereditary disease.

  15. Comparison of genetic variations of the SLCO1B1, SLCO1B3, and SLCO2B1 genes among five ethnic groups.

    PubMed

    Namgoong, Suhg; Cheong, Hyun Sub; Kim, Ji On; Kim, Lyoung Hyo; Na, Han Sung; Koh, In Song; Chung, Myeon Woo; Shin, Hyoung Doo

    2015-11-01

    Organic anion-transporting polypeptide (OATP; gene symbol, SLCO) transporters are generally involved in the uptake of multiple drugs and their metabolites at most epithelial barriers. The pattern of single-nucleotide polymorphisms (SNPs) in these transporters may be determinants of interindividual variability in drug disposition and response. The objective of this study was to define the distribution of SNPs of three SLCO genes, SLCO1B1, SLCO1B3, and SLCO2B1, in a Korean population and other ethnic groups. The study was screened using the Illumina GoldenGate assay for genomic DNA from 450 interethnic subjects, including 11 pharmacogenetic core variants and 76 HapMap tagging SNPs. The genotype distribution of the Korean population was similar to East Asian populations, but significantly different from African American and European American cohorts. These interethnic differences will be useful information for prospective studies, including genetic association and pharmacogenetic studies of drug metabolism by SLCO families.

  16. Identification of the minimum PAR4 inhibitor pharmacophore and optimization of a series of 2-methoxy-6-arylimidazo[2,1-b][1,3,4]thiadiazoles.

    PubMed

    Temple, Kayla J; Duvernay, Matthew T; Maeng, Jae G; Blobaum, Anna L; Stauffer, Shaun R; Hamm, Heidi E; Lindsley, Craig W

    2016-11-15

    This letter describes the further deconstruction of the known PAR4 inhibitor chemotypes (MWs 490-525 and with high plasma protein binding) to identify a minimum PAR4 pharmacophore devoid of metabolic liabilities and improved properties. This exercise identified a greatly simplified 2-methoxy-6-arylimidazo[2,1-b][1,3,4]thiadiazole scaffold that afforded nanomolar inhibition of both activating peptide and γ-thrombin mediated PAR4 stimulation, while reducing both molecular weight and the number of hydrogen bond donors/acceptors by ∼50%. This minimum PAR4 pharmacophore, with competitive inhibition, versus non-competitive of the larger chemotypes, allows an ideal starting point to incorporate desired functional groups to engender optimal DMPK properties towards a preclinical candidate.

  17. Association Between SLCO1B1 Gene T521C Polymorphism and Statin-Related Myopathy Risk: A Meta-Analysis of Case-Control Studies.

    PubMed

    Hou, Qingtao; Li, Sheyu; Li, Ling; Li, Yun; Sun, Xin; Tian, Haoming

    2015-09-01

    Statin-related myopathy is an important adverse effect of statin which is classically unpredictable. The evidence of association between solute carrier organic anion transporter 1B1 (SLCO1B1) gene T521C polymorphism and statin-related myopathy risk remained controversial. This study aimed to investigate this genetic association. Databases of PubMed, EMBASE, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database, and Wanfang Data were searched till June 17, 2015. Case-control studies investigating the association between SLCO1B1 gene T521C polymorphism and statin-related myopathy risk were included. The Newcastle-Ottawa Scale (NOS) was used for assessing the quality of included studies. Data were pooled by odds ratios (ORs) and their 95% confidence intervals (CIs). Nine studies with 1360 cases and 3082 controls were included. Cases of statin-related myopathy were found to be significantly associated with the variant C allele (TC + CC vs TT: OR = 2.09, 95% CI = 1.27-3.43, P = 0.003; C vs T: OR = 2.10, 95% CI = 1.43-3.09, P < 0.001), especially when statin-related myopathy was defined as an elevation of creatine kinase (CK) >10 times the upper limit of normal (ULN) or rhabdomyolysis (TC + CC vs TT: OR = 3.83, 95% CI = 1.41-10.39, P = 0.008; C vs T: OR = 2.94, 95% CI = 1.47-5.89, P = 0.002). When stratified by statin type, the association was significant in individuals receiving simvastatin (TC + CC vs TT: OR = 3.09, 95% CI = 1.64-5.85, P = 0.001; C vs T: OR = 3.00, 95% CI = 1.38-6.49, P = 0.005), but not in those receiving atorvastatin (TC + CC vs TT: OR = 1.31, 95% CI = 0.74-2.30, P = 0.35; C vs T: OR = 1.33, 95% CI = 0.57-3.12, P = 0.52). The available evidence suggests that SLCO1B1 gene T521C polymorphism is associated with an increased risk of statin-related myopathy

  18. CYP1B1, CYP1A1, MPO, and GSTP1 polymorphisms and lung cancer risk in never-smoking Korean women.

    PubMed

    Yoon, Kyong-Ah; Kim, Jin Hee; Gil, Hyea-Jin; Hwang, Hyukkee; Hwangbo, Bin; Lee, Jin Soo

    2008-04-01

    Polymorphisms in metabolic genes encoding phase I and phase II enzymes are thought to modulate the risk of lung cancer via changes in enzymatic activity. Recently, the effect of these metabolic enzymes and their interaction with environmental factors has been studied in both smokers and also never-smokers, since never-smokers are a good model in which to study genetic susceptibility at low-dose carcinogen exposure. Here, we investigated the association of CYP1A1 Ile462Val, CYP1B1 Leu432Val, GSTP1 Ile105Val, MPO G-463A polymorphisms and lung cancer risk in never-smoking Korean women. In this case-control study of 213 lung cancer patients and 213 age-matched healthy controls, we found that carrying one variant allele of the CYP1A1 Ile462Val polymorphism was associated with a significantly decreased risk of lung adenocarcinoma (adjusted odds ratio (OR)=0.63; 95% confidence interval (CI), 0.41-0.99). Furthermore, the combination of risk genotypes of CYP1B1 Leu432Val with CYP1A1 Ile462Val was associated with the risk of lung adenocarcinoma (adjusted OR=2.16; 95% CI, 1.02-4.57) as well as overall lung cancer (adjusted OR=2.23; 95% CI 1.01-4.89). The polymorphisms of GSTP1 Ile105Val and MPO G-463A showed no significant association with lung cancer. Theses results suggest that the CYP1A1 Ile462Val polymorphism is associated with a reduced risk of lung adenocarcinoma in never-smoking Korean women, whereas specific combinations of variant genotypes for metabolic enzymes increase lung cancer risk considerably.

  19. Association of genetic variants of xenobiotic and estrogen metabolism pathway (CYP1A1 and CYP1B1) with gallbladder cancer susceptibility.

    PubMed

    Sharma, Kiran Lata; Agarwal, Akash; Misra, Sanjeev; Kumar, Ashok; Kumar, Vijay; Mittal, Balraj

    2014-06-01

    Gallbladder carcinoma is a highly aggressive cancer with female predominance. Interindividual differences in the effectiveness of the activation/detoxification of environmental carcinogens and endogenous estrogens may play a crucial role in cancer susceptibility. The present study included 410 patients with carcinoma of the gallbladder (GBC) and 230 healthy subjects. This study examined association of CYP1A1-MspI, CYP1A1-Ile462Val, and CYP1B1-Val432Leu with GBC susceptibility. CYP1A1-MspI [CC] and CYP1A1-Ile462Val [iso/val] genotypes were found to be significantly associated with GBC (p=0.006 and p=0.03, respectively), as compared to healthy controls, while CYP1B1-Val432Leu was not associated with GBC. The CYP1A1 haplotype [C-val] showed a significant association with GBC (p=0.006). On stratification based on gender, the CYP1A1-MspI [CC] genotype showed an increased risk of GBC in females (p=0.018). In case-only analysis, tobacco users with CYP1A1-MspI [CT] genotypes were at a higher risk of GBC (p=0.008). Subdividing the GBC patients on the basis of gallstone status, the CYP1A1 haplotype [C-val] imparted a higher risk in patients without stones when compared to controls (p=0.001). The results remained significant even after applying Bonferroni correction. Multivariate analysis revealed an increased risk of CYP1A1 iso/val and val/val genotypes in GBC patients having BMI >25 (p=0.021). The CYP1A1 polymorphisms may confer increased risk of GBC, probably due to impaired xenobiotic or hormone metabolism through a gallstone-independent pathway.

  20. Canine external carotid vasoconstriction to methysergide, ergotamine and dihydroergotamine: role of 5-HT1B/1D receptors and α2-adrenoceptors

    PubMed Central

    Villalón, Carlos M; De Vries, Peter; Rabelo, Gonzalo; Centurión, David; Sánchez-López, Araceli; Saxena, Pramod

    1999-01-01

    The antimigraine drugs methysergide, ergotamine and dihydroergotamine (DHE) produce selective vasoconstriction in the external carotid bed of vagosympathectomized dogs anaesthetized with pentobarbital and artificially respired, but the receptors involved have not yet been completely characterized. Since the above drugs display affinity for several binding sites, including α-adrenoceptors and several 5-HT1 and 5-HT2 receptor subtypes, this study has analysed the mechanisms involved in the above responses. Intracarotid (i.c.) infusions during 1 min of methysergide (31–310 μg min−1), ergotamine (0.56–5.6 μg min−1) or DHE (5.6–31 μg min−1) dose-dependently reduced external carotid blood flow (ECBF) by up to 46±4, 37±4 and 49±5%, respectively. Blood pressure and heart rate remained unchanged. The reductions in ECBF by methysergide were abolished and even reversed to increases in animals pre-treated with GR127935 (10 μg kg−1, i.v.). The reductions in ECBF by ergotamine and DHE remained unchanged in animals pre-treated (i.v.) with prazosin (300 μg kg−1), but were partly antagonized in animals pre-treated with either GR127935 (10 or 30 μg kg−1) or yohimbine (1000 μg kg−1). Pre-treatment with a combination of GR127935 (30 μg kg−1) and yohimbine (1000 μg kg−1) abolished the responses to both ergotamine and DHE. The above doses of antagonists were shown to produce selective antagonism at their respective receptors. These results suggest that the external carotid vasoconstrictor responses to methysergide primarily involve 5-HT1B/1D receptors, whereas those to ergotamine and DHE are mediated by 5-HT1B/1D receptors as well as α2-adrenoceptors. PMID:10188968

  1. Role of spinal 5-HT5A, and 5-HT1A/1B/1D, receptors in neuropathic pain induced by spinal nerve ligation in rats.

    PubMed

    Avila-Rojas, Sabino Hazael; Velázquez-Lagunas, Isabel; Salinas-Abarca, Ana Belen; Barragán-Iglesias, Paulino; Pineda-Farias, Jorge Baruch; Granados-Soto, Vinicio

    2015-10-05

    Serotonin (5-HT) participates in pain modulation by interacting with different 5-HT receptors. The role of 5-HT5A receptor in neuropathic pain has not previously studied. The purpose of this study was to investigate: A) the role of 5-HT5A receptors in rats subjected to spinal nerve injury; B) the expression of 5-HT5A receptors in dorsal spinal cord and dorsal root ganglia (DRG). Neuropathic pain was induced by L5/L6 spinal nerve ligation. Tactile allodynia in neuropathic rats was assessed with von Frey filaments. Western blot methodology was used to determine 5-HT5A receptor protein expression. Intrathecal administration (on day 14th) of 5-HT (10-100 nmol) or 5-carboxamidotryptamine (5-CT, 0.03-0.3 nmol) reversed nerve injury-induced tactile allodynia. Intrathecal non-selective (methiothepin, 0.1-0.8 nmol) and selective (SB-699551, 1-10 nmol) 5-HT5A receptor antagonists reduced, by ~60% and ~25%, respectively, the antiallodynic effect of 5-HT (100 nmol) or 5-CT (0.3 nmol). Moreover, both selective 5-HT1A and 5-HT1B/1D receptor antagonists, WAY-100635 (0.3-1 nmol) and GR-127935 (0.3-1 nmol), respectively, partially diminished the antiallodynic effect of 5-HT or 5-CT by about 30%. Injection of antagonists, by themselves, did not affect allodynia. 5-HT5A receptors were expressed in the ipsilateral dorsal lumbar spinal cord and DRG and L5/L6 spinal nerve ligation did not modify 5-HT5A receptor protein expression in those sites. Results suggest that 5-HT5A receptors reduce pain processing in the spinal cord and that 5-HT and 5-CT reduce neuropathic pain through activation of 5-HT5A and 5-HT1A/1B/1D receptors. These receptors could be an important part of the descending pain inhibitory system.

  2. Cross-Species Integrative Functional Genomics in GeneWeaver Reveals a Role for Pafah1b1 in Altered Response to Alcohol

    PubMed Central

    Bubier, Jason A.; Wilcox, Troy D.; Jay, Jeremy J.; Langston, Michael A.; Baker, Erich J.; Chesler, Elissa J.

    2016-01-01

    Identifying the biological substrates of complex neurobehavioral traits such as alcohol dependency pose a tremendous challenge given the diverse model systems and phenotypic assessments used. To address this problem we have developed a platform for integrated analysis of high-throughput or genome-wide functional genomics studies. A wealth of such data exists, but it is often found in disparate, non-computable forms. Our interactive web-based software system, Gene Weaver (http://www.geneweaver.org), couples curated results from genomic studies to graph-theoretical tools for combinatorial analysis. Using this system we identified a gene underlying multiple alcohol-related phenotypes in four species. A search of over 60,000 gene sets in GeneWeaver's database revealed alcohol-related experimental results including genes identified in mouse genetic mapping studies, alcohol selected Drosophila lines, Rattus differential expression, and human alcoholic brains. We identified highly connected genes and compared these to genes currently annotated to alcohol-related behaviors and processes. The most highly connected gene not annotated to alcohol was Pafah1b1. Experimental validation using a Pafah1b1 conditional knock-out mouse confirmed that this gene is associated with an increased preference for alcohol and an altered thermoregulatory response to alcohol. Although this gene has not been previously implicated in alcohol-related behaviors, its function in various neural mechanisms makes a role in alcohol-related phenomena plausible. By making diverse cross-species functional genomics data readily computable, we were able to identify and confirm a novel alcohol-related gene that may have implications for alcohol use disorders and other effects of alcohol. PMID:26834590

  3. Generation and characterization of a transgenic mouse model with hepatic expression of human CYP2A6.

    PubMed

    Zhang, Qing-Yu; Gu, Jun; Su, Ting; Cui, Huadong; Zhang, Xiuling; D'Agostino, Jaime; Zhuo, Xiaoliang; Yang, Weizhu; Swiatek, Pamela J; Ding, Xinxin

    2005-12-09

    The aim of this study was to prepare and characterize a transgenic mouse model in which CYP2A6, a human P450 enzyme, is expressed specifically in the liver. CYP2A6, which is mainly expressed in human liver, is active toward many xenobiotics. Our transgene construct contained the mouse transthyretin promoter/enhancer, a full-length CYP2A6 cDNA, and a downstream neomycin-resistance gene for positive selection in embryonic stem cells. Hepatic expression of the CYP2A6 transgene was demonstrated by immunoblotting, whereas tissue specificity of CYP2A6 expression was confirmed by RNA-PCR. The transgenic mouse was further characterized after being backcrossed to the B6 strain for six generations. Hepatic microsomes from homozygous transgenic mice had activities significantly higher than those of B6 mice toward coumarin. The in vivo activity of transgenic CYP2A6 was also determined. Systemic clearance of coumarin was significantly higher in the transgenic mice than in B6 controls, consistent with the predicted role of CYP2A6 as the major coumarin hydroxylase in human liver. The CYP2A6-transgenic mouse model should be valuable for studying the in vivo function of this polymorphic human enzyme in drug metabolism and chemical toxicity.

  4. Differential Induction of CYP1A1 and CYP1B1 by Benzo[a]pyrene in Oral Squamous Cell Carcinoma Cell Lines and by Tobacco Smoking in Oral Mucosa

    PubMed Central

    Chi, Angela C.; Appleton, Kathryn; Henriod, Joel B.; Krayer, Joe W.; Marlow, Nicole M.; Bandyopadhyay, Dipankar; Sigmon, Ryan C.; Kurtz, David T.

    2009-01-01

    Polyaromatic hydrocarbons, including benzo[a]pyrene (BP), are major tobacco carcinogens. Their carcinogenic effects require metabolic activation by cytochrome p450 (CYP) enzymes. Relative CYP isoform expression is related to tissue-specific tobacco-related squamous cell carcinoma (SCC) susceptibility. There have been conflicting reports regarding relative CYP1A1 and CYP1B1 oral expression, and information regarding CYP1B1 expression in oral tissues is limited. OBJECTIVE To quantify BP- and tobacco-induced CYP1A1 and CYP1B1 expression in oral SCC cells and oral mucosa. STUDY DESIGN Real-time qPCR was performed to measure 1) BP-induced CYP1A1 and CYP1B1 mRNA expression in seven oral/other head and neck SCC cell lines 2) CYP1A1 and CYP1B1 mRNA expression in gingiva from 22 smokers and 24 nonsmokers. RESULTS SCC lines exhibited either similar induction of both isoforms or preferential CYP1A1 induction (CYP1A1-to-CYP1B1 ratios 0.8-4.3). In contrast, gingival tissues from smokers exhibited preferential CYP1B1 induction. Marked interindividual variation in CYP1A1 and CYP1B1 expression was observed among smokers. CONCLUSIONS In vitro conditions may not account for factors that modulate expression in vivo. Interindividual variation in inducible CYP1A1 and CYP1B1 expression may account in part for variation in tobacco-related oral SCC risk. PMID:19576839

  5. Electrophoretic protein analysis for the identification of doubled haploid 1A-1R, 1B-1R wheat-rye double translocation lines and for the assessment of their genetic stability.

    PubMed

    Vahl, U; Müller, G; Böhme, T

    1993-06-01

    Eighteen available doubled haploid wheat lines with a cytologically proven 1A-1R, 1B-1R double translocation, which where derived via anther culture from four crosses of the 1A-1R wheat-rye translocation cv "Amigo" with several 1B-1R wheat-rye translocation forms, were subjected to electrophoretic seed protein analysis. Besides, the five parents used in the crosses and some other wheat cultivars and doubled haploid lines (19 with a 1B-1R single translocation, 10 with a 1A-1R translocation and 7 without any 1R translocation) were also included in the investigation. It was found that the gliadin patterns visualized after SDS polyacrylamide gel electrophoresis of alcohol-soluble seed protein extracts can differentiate not only 1B-1R and 1A-1R translocation forms from wheats without any 1R-translocation chromosome, but also 1B-1R and 1A-1R wheats from each other. Moreover, 1A-1R, 1B-1R double translocation lines can be distinguished as well due to characteristic differences revealed between 1A-1R and 1B-1R translocation forms. Thus, all of tested dh1- and dh2-grains of the double translocation lines showed the expected doublet: the 1A-1R translocation ("Amigo")-typical rye band and the 1B-1R translocation ("Kawkas")-typical rye band. Consequently, gliadin patterns estimated after SDS electrophoresis may be used as markers for the fast detection of the desired 1A-1R, 1B-1R double translocation forms among 1A-1R single translocation lines, 1B-1R single translocation lines and lines without any 1R-translocation in the progenies of appropriate crosses. Furthermore, by means of gliadin tests on the dh2-generation the excellent stability of the double translocation 1A-1R, 1B-1R during more than one propagation phase has been proven. Estimations of high-molecular weight (HMW) glutenin subunits coded by 1A and 1B chromosomes are compatible with the double translocation constitution. A few deviating results can be explained by crossing-over events. Seed protein analysis

  6. The Val432Leu polymorphism of the CYP1B1 gene is associated with differences in estrogen metabolism and bone density☆

    PubMed Central

    Napoli, Nicola; Rini, Giovam Battista; Serber, Daniel; Giri, Tusar; Yarramaneni, Jayasree; Bucchieri, Salvatore; Camarda, Lawrence; Di Fede, Gaetana; Camarda, Marcello Rosolino; Jain, Sudahansu; Mumm, Steven; Armamento-Villareal, Reina

    2013-01-01

    Polymorphisms of the CYP450 genes that encode for the enzymes that metabolize estrogen are linked to hormone-related cancers. We investigated the impact of two polymorphisms of the CYP1B1 gene previously reported to be associated with hormone-related disorders on estrogen metabolism and bone mineral density (BMD), another hormone-dependent condition, in women from different ethnic backgrounds. Four hundred sixty-eight postmenopausal Caucasian women, 220 from St. Louis, MO, USA (mean age=63.5±0.53 years) and 248 from Palermo, Italy (mean age=72.9±0.44 years) participated in the study. Measurements of urinary estrogen metabolites by enzyme-linked immunoassay, serum estradiol by ultrasensitive radioimmnunoassay, and serum sex hormone-binding globulin by immunoradiometric assay were performed only in the American women, while BMD by dual energy X-ray absorptiometry and genotyping by pyrosequencing were performed in both American and Italian women. Differences in the levels of metabolites, free estradiol index and BMD were analyzed by analysis of covariance. Analysis among the American participants for the Valine432Leucine polymorphism showed that, compared to women with the Val/Val genotype, women with the Leu allele (Val/Leu and Leu/Leu) had significantly higher log-transformed values of total urinary estrogen metabolite (ng/mg-creatinine) levels (1.23±0.04, 1.35±0.02, and 1.34±0.03; p=0.03), and significantly lower BMD (gm/cm2) in the lumbar spine (1.009±0.02, 0.955±0.01 and 0.931±0.02; p=0.03) and the femoral neck (0.748± 0.02, 0.717±0.01 and 0.693±001, p =0.03) for the Val/Val, Val/Leu and Leu/Leu genotypes respectively. There were no significant differences in the urinary metabolites and BMD in the different genotypes for the Alanine119Serine polymorphism among the American women. Meanwhile, a separate analysis among the Italian women revealed no significant differences in BMD among the different genotypes for the two polymorphisms investigated. In

  7. Association of CYP1A1 and CYP1B1 polymorphisms with bone mineral density variations in postmenopausal Mexican-Mestizo women.

    PubMed

    Chávez, Bertha; Vilchis, Felipe; Rojano-Mejía, David; Coral Vázquez, Ramón Mauricio; Aguirre-García, María Del Carmen; Canto, Patricia

    2017-03-16

    Herein, we investigated potential associations between polymorphisms of genes related to estrogen metabolism and bone mineral density (BMD) in postmenopausal women. This was a cross-sectional study, in which two hundred and ninety postmenopausal Mexican-Mestizo women were studied. The BMD of the lumbar spine (LS), total hip (TH), and femoral neck (FN) was measured. The distribution of the genetic polymorphisms, including rs1799814 and rs1048943 at CYP1A1 as well as rs1056836 at CYP1B1, were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single-stranded conformational polymorphism (SSCP), and DNA sequencing. Deviations from Hardy-Weinberg equilibrium (HWE) were tested, and linkage disequilibrium (LD) was calculated by direct correlation (r(2)). Moreover, haplotype analysis was performed. All polymorphisms were in HWE. The genotype and allele distributions of the three single nucleotide polymorphisms (SNPs) studied showed no significant differences. However, statistical significance was reached when constructing haplotypes. The CG haplotype in CYP1A1 was associated with variations in LS and FN BMD after adjustment for covariates (p = 0.021 and 0.045, respectively), but the association with TH BMD was not significant. These results suggested that the CG haplotype in CYP1A1 may play an important role in the mechanism of osteoporosis and may be useful as a genetic marker.

  8. Autoradiographic Mapping of 5-HT(1B/1D) Binding Sites in the Rhesus Monkey Brain Using [carbonyl-C]zolmitriptan.

    PubMed

    Lindhe, Orjan; Almqvist, Per; Kågedal, Matts; Gustafsson, Sven-Åke; Bergström, Mats; Nilsson, Dag; Antoni, Gunnar

    2011-01-01

    Zolmitriptan is a serotonin 5-HT(1B/1D) receptor agonist that is an effective and well-tolerated drug for migraine treatment. In a human positron emission tomography study, [(11)C]zolmitriptan crossed the blood-brain barrier but no clear pattern of regional uptake was discernable. The objective of this study was to map the binding of [(11)C]zolmitriptan in Rhesus monkey brain using whole hemisphere in vitro autoradiography with [(11)C]zolmitriptan as a radioligand. In saturation studies, [(11)C]zolmitriptan showed specific (90%) binding to a population of high-affinity binding sites (Kd 0.95-5.06 nM). There was regional distribution of binding sites with the highest density in the ventral pallidum, followed by the external globus pallidus, substantia nigra, visual cortex, and nucleus accumbens. In competitive binding studies with 5-HT(1) receptor antagonists, [(11)C]zolmitriptan binding was blocked by selective 5-HT(1B) and 5-HT(1D) ligands in all target areas. There was no appreciable change in binding with the addition of a 5-HT(1A) receptor antagonist.

  9. Franck-Condon factors perturbed by damped harmonic oscillators: Solvent enhanced X 1Ag ↔ A1B1u absorption and fluorescence spectra of perylene

    NASA Astrophysics Data System (ADS)

    Wang, Chen-Wen; Yang, Ling; Zhu, Chaoyuan; Yu, Jian-Guo; Lin, Sheng-Hsien

    2014-08-01

    Damped harmonic oscillators are utilized to calculate Franck-Condon factors within displaced harmonic oscillator approximation. This is practically done by scaling unperturbed Hessian matrix that represents local modes of force constants for molecule in gaseous phase, and then by diagonalizing perturbed Hessian matrix it results in direct modification of Huang-Rhys factors which represent normal modes of solute molecule perturbed by solvent environment. Scaling parameters are empirically introduced for simulating absorption and fluorescence spectra of an isolated solute molecule in solution. The present method is especially useful for simulating vibronic spectra of polycyclic aromatic hydrocarbon molecules in which hydrogen atom vibrations in solution can be scaled equally, namely the same scaling factor being applied to all hydrogen atoms in polycyclic aromatic hydrocarbons. The present method is demonstrated in simulating solvent enhanced X 1Ag ↔ A1B1u absorption and fluorescence spectra of perylene (medium-sized polycyclic aromatic hydrocarbon) in benzene solution. It is found that one of six active normal modes v10 is actually responsible to the solvent enhancement of spectra observed in experiment. Simulations from all functionals (TD) B3LYP, (TD) B3LYP35, (TD) B3LYP50, and (TD) B3LYP100 draw the same conclusion. Hence, the present method is able to adequately reproduce experimental absorption and fluorescence spectra in both gas and solution phases.

  10. A comparative molecular field analysis of cytochrome P450 2A5 and 2A6 inhibitors.

    PubMed

    Poso, A; Gynther, J; Juvonen, R

    2001-03-01

    Structure-activity relationships of 23 P450 2A5 and 2A6 inhibitors were analysed using the CoMFA and GOLPE/GRID with smart region definition (SRD). The predictive power of the resulting models was validated using five compounds not belonging to the model set. All models have high internal and external predictive power and resulting 3D-QSAR models are supporting each other. Both Sybyl and GOLPE highlight properties near lactone moiety to be important for 2A5 and 2A6 inhibition. Another important feature for pIC50 was the size of the substituent in the 7-positon of coumarin. The models suggest that the 2A5 binding site is larger that that of 2A6 due to larger steric regions in the CoMFA coefficient maps and corresponding GOLPE maps. In addition, the maps reveal that 2A6 disfavours negative charge near the lactone moiety of coumarin.

  11. Celery extract inhibits mouse CYP2A5 and human CYP2A6 activities via different mechanisms.

    PubMed

    Deng, Xiao; Pu, Qianghong; Wang, Erhao; Yu, Chao

    2016-12-01

    Human cytochrome P450 (CYP) 2A6 participates in the metabolism of nicotine and precarcinogens, thus the deliberate inhibition of CYP2A6 may reduce cigarette consumption and therefore reduce the risk of developing the types of cancer associated with smoking. The inhibitory effects and mechanisms of celery (Apium graveolens) extract on mouse CYP2A5 and human CYP2A6 activity remain unclear. These effects were investigated in mouse and human liver microsomes using coumarin 7-hydroxylation in a probe reaction. Celery extract reduced CYP2A5 and CYP2A6 activities in vitro in a dose-dependent manner. In vivo experiments also showed that celery extract markedly decreased CYP2A5 activity. The inhibition of celery extract on CYP2A5 was time- and nicotinamide adenine dinucleotide phosphate (NADPH)-independent, and was markedly reduced by ultracentrifugation. Additionally, the inhibition of celery extract on CYP2A6 was time and NADPH-dependent. Levels of inhibition were characterized by a Ki, the measure of the tightness of bonds between the enzyme and its inhibitor, of 266.4 µg/ml for CYP2A5, and a Ki of 1,018 µg/ml and Kinact of 0.3/min for CYP2A6. Kinact is the maximal rate of enzyme inactivation at a saturating concentration of inhibitor. The coumarin derivative 5-methoxypsoralen present in celery extract did not solely to the inhibition of CYP2A5/6 activity. In conclusion, celery extract inhibited the levels of mouse CYP2A5 and human CYP2A6 activity via different mechanisms: Mixed competitive inhibition for CYP2A5 and mechanism-based inhibition for CYP2A6.

  12. Celery extract inhibits mouse CYP2A5 and human CYP2A6 activities via different mechanisms

    PubMed Central

    Deng, Xiao; Pu, Qianghong; Wang, Erhao; Yu, Chao

    2016-01-01

    Human cytochrome P450 (CYP) 2A6 participates in the metabolism of nicotine and precarcinogens, thus the deliberate inhibition of CYP2A6 may reduce cigarette consumption and therefore reduce the risk of developing the types of cancer associated with smoking. The inhibitory effects and mechanisms of celery (Apium graveolens) extract on mouse CYP2A5 and human CYP2A6 activity remain unclear. These effects were investigated in mouse and human liver microsomes using coumarin 7-hydroxylation in a probe reaction. Celery extract reduced CYP2A5 and CYP2A6 activities in vitro in a dose-dependent manner. In vivo experiments also showed that celery extract markedly decreased CYP2A5 activity. The inhibition of celery extract on CYP2A5 was time- and nicotinamide adenine dinucleotide phosphate (NADPH)-independent, and was markedly reduced by ultracentrifugation. Additionally, the inhibition of celery extract on CYP2A6 was time and NADPH-dependent. Levels of inhibition were characterized by a Ki, the measure of the tightness of bonds between the enzyme and its inhibitor, of 266.4 µg/ml for CYP2A5, and a Ki of 1,018 µg/ml and Kinact of 0.3/min for CYP2A6. Kinact is the maximal rate of enzyme inactivation at a saturating concentration of inhibitor. The coumarin derivative 5-methoxypsoralen present in celery extract did not solely to the inhibition of CYP2A5/6 activity. In conclusion, celery extract inhibited the levels of mouse CYP2A5 and human CYP2A6 activity via different mechanisms: Mixed competitive inhibition for CYP2A5 and mechanism-based inhibition for CYP2A6. PMID:28101244

  13. Reverse type I binding spectra of human cytochrome P450 1B1 induced by flavonoid, stilbene, pyrene, naphthalene, phenanthrene, and biphenyl derivatives that inhibit catalytic activity: a structure-function relationship study.

    PubMed

    Shimada, Tsutomu; Tanaka, Katsuhiro; Takenaka, Shigeo; Foroozesh, Maryam K; Murayama, Norie; Yamazaki, Hiroshi; Guengerich, F Peter; Komori, Masayuki

    2009-07-01

    Fifty-one chemicals including derivatives of 16 flavonoids, three stilbenes, six pyrenes, seven naphthalenes, seven phenanthrenes, 10 biphenyls, 17beta-estradiol, and estrone were examined for their abilities to induce reverse type I binding spectra with human cytochrome P450 (P450) 1B1 and to inhibit 7-ethoxyresorufin O-deethylation (EROD) activities catalyzed by P450 1B1. Forty-nine chemicals showed reverse type I spectra with P450 1B1, and we found that 3,5,7-trihydroxyflavone, 3',4'-dimethoxy-5,7-dihydroxyflavone, 4'-methoxy-5,7-dihydroxyflavone, alpha- and beta-naphthoflavones, 2,4,3',5'-tetramethoxystilbene, pyrene, and several acetylenic pyrenes and phenanthrenes were strong inducers of the spectra and also potent inhibitors of EROD activities catalyzed by P450 1B1. The spectral dissociation constant (K(s)) and the magnitude of the binding (DeltaA(max)/K(s)) of 49 chemicals were correlated with the inhibition potencies of EROD activities by these chemicals [correlation coefficients (r) of 0.72 and 0.74, respectively]. The K(s) and DeltaA(max)/K(s) values were more correlated with IC(50) values when compared in a group of derivatives of flavonoids, stilbenes, and estrogens (r = 0.81 and 0.88, respectively) or a group of derivatives of pyrenes, naphthalenes, phenanthrenes, and biphenyls (r = 0.88 and 0.91, respectively). Among 14 flavonoids examined, 3,5,7-trihydroxyflavone and 4'-methoxy- and 3',4'-dimethoxy-5,7-dihydroxyflavone were more active than flavone in interacting with P450 1B1, but the respective 7,8-dihydroxyflavones were less active. Pyrene itself was highly active in interacting with P450 1B1, but its binding was slightly decreased when substituted with acetylenic groups. In contrast, substitution of naphthalene with methyl and ethyl propargyl ethers led to more interaction with P450 1B1 than with naphthalene itself. Similarly, substitution on phenanthrene or biphenyl with acetylenic groups and propargyl ethers increased affinities to P450 1B1

  14. Tritium analyses of COBRA-1A2 beryllium pebbles

    SciTech Connect

    Baldwin, D.L.

    1998-03-01

    Selected tritium measurements have been completed for the COBRA-1A2 experiment C03 and D03 beryllium pebbles. The completed results, shown in Tables 1, 2, and 3, include the tritium assay results for the 1-mm and 3-mm C03 pebbles, and the 1-mm D03 pebbles, stepped anneal test results for both types of 1-mm pebbles, and the residual analyses for the stepped-anneal specimens. All results have been reported with date-of-count and are not corrected for decay. Stepped-anneal tritium release response is provided in addenda.

  15. Receptor specificity and trigemino-vascular inhibitory actions of a novel 5-HT1B/1D receptor partial agonist, 311C90 (zolmitriptan)

    PubMed Central

    Martin, G R; Robertson, A D; MacLennan, S J; Prentice, D J; Barrett, V J; Buckingham, J; Honey, A C; Giles, H; Moncada, S

    1997-01-01

    311C90 (zolmitriptan zomig: (S)-4[[3-[2-(dimethylamino)ethyl]-1H-indol-5-yl]methyl]-2-oxazolidinone) is a novel 5-HT1B/1D receptor agonist with proven efficacy in the acute treatment of migraine. Here, we describe the receptor specificity of the drug and its actions on trigeminal-evoked plasma protein extravasation into the dura mater of the anaesthetized guinea-pig. At the ‘5-HT1B-like' receptor mediating vascular contraction (rabbit saphenous vein), the compound was a potent (p[A50]=6.79±0.06) partial agonist achieving 77±4% of the maximum effect to 5-hydroxytryptamine (5-HT). In the same experiments, sumatriptan (p[A50]=6.48±0.04) was half as potent as 311C90 and produced 97±2% of the 5-HT maximum effect. Studies in which receptor inactivation methods were used to estimate the affinity (pKA) and efficacy relative to 5-HT (τrel.) for each agonist confirmed that 311C90 exhibits higher affinity than sumatriptan (pKA=6.63±0.04 and 6.16±0.03, respectively) and that both drugs are partial agonists relative to 5-HT (τrel=0.61±0.03 and 0.63±0.10, respectively, compared to 5-HT=1.0). Consistent with its effects in rabbit saphenous vein, 311C90 also produced concentration-dependent contractions of primate basilar artery and human epicardial coronary artery rings. In basilar artery, agonist potency (p[A50]=6.92±0.07) was similar to that demonstrated in rabbit saphenous vein, again being 2–3 fold higher than for sumatriptan (p[A50]=6.46±0.03). Both agonists produced about 50% of the maximum response obtained with 5-HT in the same preparations. In rings of human coronary artery, the absolute potency of 311C90 and sumatriptan was higher than in primate basilar artery (p[A50]=7.3±0.1 and 6.7±0.1, respectively), but maximum effects relative to 5-HT were lower (37±8% and 35±7%, respectively). In both types of vessel, the inability of 5-HT1B/1D agonists to achieve the same maximum as the endogenous agonist 5-HT is explained by the additional presence of 5-HT2A

  16. Analysis of Dibenzo[def,p]chrysene-Deoxyadenosine Adducts in Wild-Type and Cytochrome P450 1b1 Knockout Mice using Stable-Isotope Dilution UHPLC-MS/MS

    PubMed Central

    Harper, Tod A.; Morré, Jeff; Lauer, Fredine T.; McQuistan, Tammie J.; Hummel, Jessica M.; Burchiel, Scott W.; Williams, David E.

    2015-01-01

    The polycyclic aromatic hydrocarbon (PAH), dibenzo[def,p]chrysene (DBC; also known as dibenzo[a,l]pyrene), is a potent carcinogen in animal models and a class 2A human carcinogen. Recent investigations into DBC-mediated toxicity identified DBC as a potent immunosuppressive agent similar to the well-studied immunotoxicant 7,12-dimethylbenz[a]anthracene (DMBA). DBC, like DMBA, is bioactivated by cytochrome P450 (CYP) 1B1 and forms the reactive metabolite DBC-11,12-diol-13,14-epoxide (DBCDE). DBCDE is largely responsible for the genotoxicity associated with DBC exposure. The immunosuppressive properties of several PAHs are also linked to genotoxic mechanisms. Therefore, this study was designed to identify DBCDE-DNA adduct formation in the spleen and thymus of wild-type and cytochrome P450 1b1 (Cyp1b1) knockout (KO) mice using a highly sensitive stable-isotope dilution UHPLC-MS/MS method. Stable-isotope dilution UHPLC-MS/MS identified the major DBC adducts (±)-anti-cis-DBCDE-dA and (±)-anti-trans-DBCDE-dA in the lung, liver, and spleen of both WT and Cyp1b1 KO mice. However, adduct formation in the thymus was below the level of quantitation for our method. Additionally, adduct formation in Cyp1b1 KO mice was significantly reduced compared to wild-type (WT) mice receiving DBC via oral gavage. In conclusion, the current study identifies for the first time DBCDE-dA adducts in the spleen of mice supporting the link between genotoxicity and immunosuppression, in addition to supporting previous studies identifying Cyp1b1 as the primary CYP involved in DBC bioactivation to DBCDE. The high levels of DBC-DNA adducts identified in the spleen, along with the known high levels of Cyp1b1 expression in this organ, supports further investigation into DBC-mediated immunotoxicity. PMID:25868132

  17. Cytochrome P450 1A1 and 1B1 in human blood lymphocytes are not suitable as biomarkers of exposure to dioxin-like compounds: polymorphisms and interindividual variation in expression and inducibility.

    PubMed

    van Duursen, Majorie B M; Sanderson, J Thomas; van den Berg, Martin

    2005-05-01

    Cytochrome P450 1A1 (CYP1A1) and 1B1 (CYP1B1) are phase I enzymes, the expression of which can be affected by many environmental compounds, including dioxins and dioxin-like compounds. Because CYP1A1 and CYP1B1 expression can easily be determined in peripheral blood lymphocytes, it is often suggested as biomarker of exposure to these compounds. In this study we investigated the interindividual differences in constitutive and induced CYP1A1-catalyzed ethoxyresorufin-O-deethylase (EROD) activity and CYP1A1 and CYP1B1 gene expression in human blood lymphocytes in a group of ten non-smoking females. Freshly isolated lymphocytes were cultured in medium containing the mitogen PHA and were exposed to the most potent dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or the less potent dioxin-like polychlorinated biphenyl 126 (PCB126). In addition, we determined the occurrence of the CYP1A1 MspI and CYP1B1 Leu432Val polymorphisms. All individuals showed a concentration-dependent increase of EROD activity by TCDD, which was significantly correlated with an increase in CYP1A1, but not CYP1B1 expression. The maximum induced EROD activity by TCDD was very different among the individuals, but the EC50 values were about the same. PCB126 also caused a concentration-dependent increase of EROD activity, but was a factor 100-1000 less potent than TCDD among the individuals. The allele frequencies for CYP1A1 MspI and CYP1B1 Leu432Val reflected a normal Caucasian population and in this study the polymorphisms had no apparent effect on the expression and activity of these enzymes. Our study shows a large interindividual variability in constitutive and induced EROD activity, and CYP1A1 and CYP1B1 expression in human lymphocytes. In addition, dioxin concentrations at which effects were observed in our in vitro study are about 10-fold higher than the human blood levels found in vivo, indicating that EROD activity and CYP1A1 and CYP1B1 expression in human lymphocytes might not be

  18. Doppler-free two-photon excitation spectroscopy and the Zeeman effects of the S1 1B1u(v21=1) <-- S0 1Ag(v=0) band of naphthalene-d8.

    PubMed

    Okubo, Mitsushi; Wang, Jinguo; Baba, Masaaki; Misono, Masatoshi; Kasahara, Shunji; Katô, Hajime

    2005-04-08

    Doppler-free two-photon excitation spectrum and the Zeeman effect of the S1 1B1u(v21=1) <-- S0 1Ag(v=0) transition of naphthalene-d8 have been measured. 908 lines of Q(Ka)Q(J)KaKc transition of J=0-41, Ka=0-20 were assigned, and the molecular constants of the S1 1B1u(v21=1) state were determined. Perturbations were observed, and those were identified as originating from Coriolis interaction. No perturbation originating from an interaction with triplet state was observed. The Zeeman splittings from lines of a given J were observed to increase with Kc, and those of the Kc=J levels increased linearly with J. The Zeeman effects are shown to be originating from the magnetic moment of the S1 1B1u state, which is along the c axis and is induced by mixing of the S2 1B3u state to the S1 1B1u state by J-L coupling. Rotationally resolved levels were found not to be mixed with a triplet state from the Zeeman spectra. Accordingly, it is concluded that nonradiative decay of an isolated naphthalene excited to low rovibronic levels in the S1 1B1u state does not occur through the intersystem mixing. This is at variance with generally accepted understanding of the pathways of the nonradiative decay.

  19. CYP1A1 (Ile462Val), CYP1B1 (Ala119Ser and Val432Leu), GSTM1 (null), and GSTT1 (null) polymorphisms and bladder cancer risk in a Turkish population.

    PubMed

    Berber, Ufuk; Yilmaz, Ismail; Yilmaz, Omer; Haholu, Aptullah; Kucukodaci, Zafer; Ates, Ferhat; Demirel, Dilaver

    2013-01-01

    We aimed to investigate bladder cancer risk with reference to polymorphic variants of cytochrome p450 (CYP) 1A1, CYP1B1, glutathione S-transferase (GST) M1, and GSTT1 genes in a case control study. Polymorphisms were examined in 114 bladder cancer patients and 114 age and sex-matched cancer-free subjects. Genotypes were determined using allele specific PCR for CYP1A1 and CYP1B1 genes, and by multiplex PCR and melting curve analysis for GSTM1 and GSTT1 genes. Our results revealed a statistically significant increased bladder cancer risk for GSTT1 null genotype carriers with an odds ratio of 3.06 (95% confidence interval=1.39-6.74, p=0.006). Differences of CYP1A1, CYP1B1 and GSTM1 genotype frequencies were not statistically significant between patients and controls. However, the specific combination of GSTM1 null, GSTT1 null, and CYP1B1 codon 119 risk allele carriers and specific combination of GSTM1 present, GSTT1 null, and CYP1B1 432 risk allele carriers exhibited increased cancer risk in the combined analysis. We did not observe any association between different genotype groups and prognostic tumor characteristics of bladder cancer. Our results indicate that inherited absence of GSTT1 gene may be associated with bladder cancer susceptibility, and specific combinations of GSTM1, GSTT1 and CYP1B1 gene polymorphisms may modify bladder cancer risk in the Turkish population, without any association being observed for CYP1A1 gene polymorphism and bladder cancer risk.

  20. CYP1A1 and CYP1B1 gene expression and DNA adduct formation in normal human mammary epithelial cells exposed to benzo[a]pyrene in the absence or presence of chlorophyllin.

    PubMed

    John, Kaarthik; Divi, Rao L; Keshava, Channa; Orozco, Christine C; Schockley, Marie E; Richardson, Diana L; Poirier, Miriam C; Nath, Joginder; Weston, Ainsley

    2010-06-28

    Benzo[a]pyrene (BP) is a potent pro-carcinogen and ubiquitous environmental pollutant. Here, we examined the induction and modulation of CYP1A1 and CYP1B1 and 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG) adduct formation in DNA from 20 primary normal human mammary epithelial cell (NHMEC) strains exposed to BP (4muM) in the absence or presence of chlorophyllin (5muM). Real-time polymerase chain reaction (RT-PCR) analysis revealed strong induction of both CYP1A1 and CYP1B1 by BP, with high levels of inter-individual variability. Variable BPdG formation was found in all strains by r7, t8-dihydroxy-t-9, 10 epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA chemiluminescence assay (CIA). Chlorophyllin mitigated BP-induced CYP1A1 and CYP1B1 gene expression in all 20 strains when administered with BP. Chlorophyllin, administered prior to BP-exposure, mitigated CYP1A1 expression in 18/20 NHMEC strains (p<0.005) and CYP1B1 expression in 17/20 NHMEC strains (p<0.005). Maximum percent reductions of CYP1A1 and CYP1B1 gene expression and BPdG adduct formation were observed when cells were pre-dosed with chlorophyllin followed by administration of the carcinogen with chlorophyllin (p<0.005 for CYP1A1 and CYP1B1 expression and p<0.0005 for BPdG adducts). Therefore, chlorophyllin is likely to be a good chemoprotective agent for a large proportion of the human population.

  1. Main contribution of the cytochrome P450 isoenzyme 1A2 (CYP1A2) to N-demethylation and 5-sulfoxidation of the phenothiazine neuroleptic chlorpromazine in human liver--A comparison with other phenothiazines.

    PubMed

    Wójcikowski, Jacek; Boksa, Jan; Daniel, Władysława A

    2010-10-15

    The aim of the present study was to identify cytochrome P450 (CYP) isoenzymes involved in the 5-sulfoxidation, mono-N-demethylation and di-N-demethylation of the aliphatic-type phenothiazine neuroleptic chlorpromazine in human liver. Experiments were performed in vitro using cDNA-expressed human CYP isoforms (Supersomes 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4), liver microsomes from different donors and CYP-selective inhibitors. The obtained results indicate that CYP1A2 is the only CYP isoform that catalyzes the mono-N-demethylation and di-N-demethylation of chlorpromazine (100%) and is the main isoform responsible for chlorpromazine 5-sulfoxidation (64%) at a therapeutic concentration of the drug (10 microM). CYP3A4 contributes to a lesser degree to chlorpromazine 5-sulfoxidation (34%). The role of CYP2B6, CYP2C19 and CYP2D6 in catalyzing of the latter reaction is negligible (0.1-2%). Similar results were obtained at a higher, non-therapeutic concentration of the drug (100 microM); however, the contribution of CYP1A2 to chlorpromazine mono-N-demethylation was noticeably lower (75%), mostly in favour of CYP2C19 and CYP3A4 (about 12% each). The obtained results indicate that the catalysis of chlorpromazine N-demethylation and 5-sulfoxidation in humans exhibits a stricter CYP1A2 preference compared to the previously tested phenothiazines (promazine, perazine, and thioridazine). Hence pharmacokinetic interactions involving chlorpromazine and CYP1A2 substrates and inhibitors are likely to occur. Considering strong dopaminergic D(2), noradrenergic alpha(1) and cholinergic M(1) receptor blocking properties of chlorpromazine and some of its metabolites, as well as their serious side effects, the obtained results may be of pharmacological and clinical importance.

  2. A comparative molecular field analysis of cytochrome P450 2A5 and 2A6 inhibitors

    NASA Astrophysics Data System (ADS)

    Poso, Antti; Gynther, Jukka; Juvonen, Risto

    2001-03-01

    Structure-activity relationships of 23 P450 2A5 and 2A6 inhibitors were analysed using the CoMFA [1] and GOLPE/GRID with smart region definition (SRD) [2]. The predictive power of the resulting models was validated using five compounds not belonging to the model set. All models have high internal and external predictive power and resulting 3D-QSAR models are supporting each other. Both Sybyl and GOLPE highlight properties near lactone moiety to be important for 2A5 and 2A6 inhibition. Another important feature for pIC50 was the size of the substituent in the 7-positon of coumarin. The models suggest that the 2A5 binding site is larger that that of 2A6 due to larger steric regions in the CoMFA coefficient maps and corresponding GOLPE maps. In addition, the maps reveal that 2A6 disfavours negative charge near the lactone moiety of coumarin.

  3. Structural comparison of cytochromes P450 2A6, 2A13, and 2E1 with pilocarpine

    SciTech Connect

    DeVore, Natasha M.; Meneely, Kathleen M.; Bart, Aaron G.; Stephens, Eva S.; Battaile, Kevin P.; Scott, Emily E.

    2013-11-20

    Human xenobiotic-metabolizing cytochrome P450 (CYP) enzymes can each bind and monooxygenate a diverse set of substrates, including drugs, often producing a variety of metabolites. Additionally, a single ligand can interact with multiple CYP enzymes, but often the protein structural similarities and differences that mediate such overlapping selectivity are not well understood. Even though the CYP superfamily has a highly canonical global protein fold, there are large variations in the active site size, topology, and conformational flexibility. We have determined how a related set of three human CYP enzymes bind and interact with a common inhibitor, the muscarinic receptor agonist drug pilocarpine. Pilocarpine binds and inhibits the hepatic CYP2A6 and respiratory CYP2A13 enzymes much more efficiently than the hepatic CYP2E1 enzyme. To elucidate key residues involved in pilocarpine binding, crystal structures of CYP2A6 (2.4 {angstrom}), CYP2A13 (3.0 {angstrom}), CYP2E1 (2.35 {angstrom}), and the CYP2A6 mutant enzyme, CYP2A6 I208S/I300F/G301A/S369G (2.1 {angstrom}) have been determined with pilocarpine in the active site. In all four structures, pilocarpine coordinates to the heme iron, but comparisons reveal how individual residues lining the active sites of these three distinct human enzymes interact differently with the inhibitor pilocarpine.

  4. CYP2A6- and CYP2A13-catalyzed metabolism of the nicotine Δ5'(1')iminium ion.

    PubMed

    von Weymarn, Linda B; Retzlaff, Cassandra; Murphy, Sharon E

    2012-11-01

    Nicotine, the major addictive agent in tobacco, is metabolized primarily by CYP2A6-catalyzed oxidation. The product of this reaction, 5'-hydroxynicotine, is in equilibrium with the nicotine Δ5'(1')iminium ion and is further metabolized to cotinine. We reported previously that both CYP2A6 and the closely related extrahepatic enzyme CYP2A13 were inactivated during nicotine metabolism; however, inactivation occurred after metabolism was complete. This led to the hypothesis that oxidation of a nicotine metabolite, possibly the nicotine Δ5'(1')iminium ion, was responsible for generating the inactivating species. In the studies presented here, we confirm that the nicotine Δ5'(1')iminium ion is an inactivator of both CYP2A6 and CYP2A13, and inactivation depends on time, concentration, and the presence of NADPH. Inactivation was not reversible and was accompanied by a parallel loss in spectrally active protein, as measured by reduced CO spectra. These data are consistent with the characterization of the nicotine Δ5'(1')iminium ion as a mechanism-based inactivator of both CYP2A13 and CYP2A6. We also confirm that both CYP2A6 and CYP2A13 catalyze the metabolism of the nicotine Δ5'(1')iminium ion to cotinine and provide evidence that both enzymes catalyze the sequential metabolism of the nicotine Δ5'(1')iminium ion. That is, a fraction of the cotinine formed may not be released from the enzyme before further oxidation to 3'-hydroxycotinine.

  5. Estrogen Receptor α Increases Basal and Cigarette Smoke Extract-Induced Expression of CYP1A1 and CYP1B1, but not GSTP1, in Normal Human Bronchial Epithelial Cells

    PubMed Central

    Han, W; Pentecost, BT; Pietropaolo, RL; Fasco, MJ; Spivack, SD

    2005-01-01

    Gender-specific estrogen receptor α (ERα) expression may plausibly influence lung carcinogenesis in females. Initial genome-wide microarray studies confirmed that carcinogen metabolism genes (CYP1A1, CYP1B1) were those most responsive to cigarette smoke extract (CSE) in normal bronchial epithelial (NHBE) cells. These two genes encoding phase I bioactivating enzymes and the GSTP1 gene encoding a phase II deactivating enzyme were then tested for induction by ERα. NHBE cells (native ERα−) were transfected with wild-type ERα-adenoviral constructs, and then exposed to CSE, 17β-estradiol (E2), and/or the ERα inhibitor, ICI 182,780. The expression levels of CYP1A1, CYP1B1 and GSTP1 were then determined by RNA-specific quantitative RT-PCR and immunoassay. ERα increased the basal expression of CYP1B1 4.04-fold (p<0.01) at the mRNA level and 6.5-fold at the protein level. ERα also increased the CSE-induced mRNA expression of CYP1B1 2.26-fold (p<0.01), but not the protein expression. ERα did not alter the CYP1A1 mRNA levels, but did increase protein expression 2.0-fold (p<0.01) on CSE exposure, and 6.2-fold (p<0.01) upon E2 exposure. These effects could be inhibited by ICI 182,780. ERα did not alter the expression of GSTP1. ChIP assay confirmed ERα binding to CYP1B1 promoter near the transcription start site. These results suggest that ERα regulates the CYP1B1 expression at a transcriptional level, and CYP1A1 expression at a translational level. These data raise the possibility that inter-gender differences in expression of ERα that are known to exist in human lung may contribute to inter-individual expression differences in CYP1A1 and CYP1B1, and to differences in carcinogen metabolism and mutation. PMID:16010691

  6. Human natural killer cell microRNA: differential expression of MIR181A1B1 and MIR181A2B2 genes encoding identical mature microRNAs.

    PubMed

    Presnell, S R; Al-Attar, A; Cichocki, F; Miller, J S; Lutz, C T

    2015-01-01

    Natural killer (NK) and T lymphocytes share many properties, yet only NK cells respond rapidly to infection and cancer without pre-activation. We found that few microRNAs (miRNAs) differed significantly between human NK and T cells. Among those miRNAs, miR-181a and miR-181b levels rose during NK cell differentiation. Prior studies indicate that miR-181a and miR-181b are critical for human NK cell development and are co-transcribed from genes on chromosome 1 (MIR181A1B1) and on chromosome 9 (MIR181A2B2). We mapped human MIR181A1B1 and MIR181A2B2 transcription start sites to 78.3 kb and 34.0 kb upstream of the mature miRNAs, generating predominantly unspliced transcripts of 80-127 kb and ~60 kb, respectively. Unlike mouse thymocytes, human T cells expressed both MIR181A1B1 and MIR181A2B2. We tested the hypothesis that NK cells differentially transcribe the two genes during development and in response to immune regulatory cytokines. During NK-cell differentiation, MIR181A2B2 expression rose markedly and exceeded that of MIR181A1B1. TGF-β treatment increased NK-cell MIR181A2B2 transcription, whereas IL-2, IL-15 and IL-12/IL-18 treatments upregulated MIR181A1B1. The MIR181A2B2 promoter was strongly transactivated by SMAD3 and SMAD4 transcription factors, suggesting that TGF-β signaling upregulates MIR181A2B2 expression, at least in part, through SMAD-dependent promoter activation.

  7. Charakterisierung von Sulfotransferasen im Gastrointestinaltrakt von Mensch und Ratte und Aktivierung von Promutagenen in V79-Zellen, die eine intestinale Form (1B1) des Menschen und der Ratte exprimieren

    NASA Astrophysics Data System (ADS)

    Teubner, Wera

    2001-05-01

    Die Ausstattung der gastrointestinalen Mukosa des Menschen und der Ratte mit Sulfotransferasen wurde mit Hilfe von Immunodetektion und Enzymaktivitätsmessungen untersucht. In Proben aus Colon und Rektum von 39 Personen wurden die Formen h1A1, h1A3 und h1B1 identifiziert, wobei in einer weiteren Probe, die als einzige von einem an Colitis Ulcerosa erkrankten Patienten stammte, keine Sulfotransferasen nachgewiesen werden konnten. Bei der Immunblot-Analyse war das Expressionsmuster der einzelnen Formen in allen Proben ähnlich. In wenigen Proben waren die relativen Signalintensitäten der h1A1 und der h1B1 um die Hälfte erniedrigt. Der Gehalt von SULT an zytosolischem Protein zeigte einen bis zu 8 - 10fachen Unterschied, er betrug jedoch bei zwei Dritteln der Proben zwischen 0,15 und 0,3 (h1A1 und h1A3) bzw. 0,6 und 0,8 Promille (h1B1). Die Variation konnte nicht auf Alter, Geschlecht oder Krankheitsbild der Patienten zurückgeführt werden. Auch der für die allelischen Varianten der h1A1 beschriebene Effekt auf die Enzymaktiviät bzw. Stabilität konnte in der Menge an immunreaktivem Protein nicht in diesem Ausma detektiert werden. Die Allelhäufigkeit von h1A1*R und h1A1*H war gegenüber der gesunden Bevölkerung nicht verändert. In den sieben Proben aus dem Dünndarm (Coecum, viermal Ileum, Jejunum) konnten zusätzlich die Formen h1E1 und h2A1 identifiziert werden. Ein möglicherweise der Form h1C1 entsprechendes Protein wurde im Magen detektiert. Im Vergleich zum Menschen war die Expression in der Ratte stärker auf die Leber konzentriert. Während beim Menschen in allen untersuchten Abschnitten Sulfotransferasen in Mengen detektiert wurden, die in zwei Fällen (h1B1 und h1A3) sogar den Gehalt in der Leber überstiegen, beschränkte sich die Expression in der Ratte auf im Vergleich zur Leber geringe Mengen im Magen und Dickdarm. Nachgewiesen wurden die r1B1, r1A1 sowie eine nicht identifizierte Form von 35kD, bei der es sich vermutlich um die r1C2 handelt. Im

  8. Molecular diagnosis of distal renal tubular acidosis in Tunisian patients: proposed algorithm for Northern Africa populations for the ATP6V1B1, ATP6V0A4 and SCL4A1 genes

    PubMed Central

    2013-01-01

    Background Primary distal renal tubular acidosis (dRTA) caused by mutations in the genes that codify for the H + −ATPase pump subunits is a heterogeneous disease with a poor phenotype-genotype correlation. Up to now, large cohorts of dRTA Tunisian patients have not been analyzed, and molecular defects may differ from those described in other ethnicities. We aim to identify molecular defects present in the ATP6V1B1, ATP6V0A4 and SLC4A1 genes in a Tunisian cohort, according to the following algorithm: first, ATP6V1B1 gene analysis in dRTA patients with sensorineural hearing loss (SNHL) or unknown hearing status. Afterwards, ATP6V0A4 gene study in dRTA patients with normal hearing, and in those without any structural mutation in the ATP6V1B1 gene despite presenting SNHL. Finally, analysis of the SLC4A1 gene in those patients with a negative result for the previous studies. Methods 25 children (19 boys) with dRTA from 20 families of Tunisian origin were studied. DNAs were extracted by the standard phenol/chloroform method. Molecular analysis was performed by PCR amplification and direct sequencing. Results In the index cases, ATP6V1B1 gene screening resulted in a mutation detection rate of 81.25%, which increased up to 95% after ATP6V0A4 gene analysis. Three ATP6V1B1 mutations were observed: one frameshift mutation (c.1155dupC; p.Ile386fs), in exon 12; a G to C single nucleotide substitution, on the acceptor splicing site (c.175-1G > C; p.?) in intron 2, and one novel missense mutation (c.1102G > A; p.Glu368Lys), in exon 11. We also report four mutations in the ATP6V0A4 gene: one single nucleotide deletion in exon 13 (c.1221delG; p.Met408Cysfs*10); the nonsense c.16C > T; p.Arg6*, in exon 3; and the missense changes c.1739 T > C; p.Met580Thr, in exon 17 and c.2035G > T; p.Asp679Tyr, in exon 19. Conclusion Molecular diagnosis of ATP6V1B1 and ATP6V0A4 genes was performed in a large Tunisian cohort with dRTA. We identified three different ATP6V1

  9. Casein Kinase 2 Is a Novel Regulator of the Human Organic Anion Transporting Polypeptide 1A2 (OATP1A2) Trafficking.

    PubMed

    Chan, Ting; Cheung, Florence Shin Gee; Zheng, Jian; Lu, Xiaoxi; Zhu, Ling; Grewal, Thomas; Murray, Michael; Zhou, Fanfan

    2016-01-04

    Human organic anion transporting polypeptides (OATPs) mediate the influx of many important drugs into cells. Casein kinase 2 (CK2) is a critical protein kinase that phosphorylates >300 protein substrates and is dysregulated in a number of disease states. Among the CK2 substrates are several transporters, although whether this includes human OATPs has not been evaluated. The current study was undertaken to evaluate the regulation of human OATP1A2 by CK2. HEK-239T cells in which OATP1A2 was overexpressed were treated with CK2 specific inhibitors or transfected with CK2 specific siRNA, and the activity, expression, and subcellular trafficking of OATP1A2 was evaluated. CK2 inhibition decreased the uptake of the prototypic OATP1A2 substrate estrone-3-sulfate (E3S). Kinetic studies revealed that this was due to a decrease in the maximum velocity (Vmax) of E3S uptake, while the Michaelis constant was unchanged. The cell surface expression, but not the total cellular expression of OATP1A2, was impaired by CK2 inhibition and knockdown of the catalytic α-subunits of CK2. CK2 inhibition decreased the internalization of OATP1A2 via a clathrin-dependent pathway, decreased OATP1A2 recycling, and likely impaired OATP1A2 targeting to the cell surface. Consistent with these findings, CK2 inhibition also disrupted the colocalization of OATP1A2 and Rab GTPase (Rab)4-, Rab8-, and Rab9-positive endosomal and secretory vesicles. Taken together, CK2 has emerged as a novel regulator of the subcellular trafficking and stability of OATP1A2. Because OATP1A2 transports many molecules of physiological and pharmacological importance, the present data may inform drug selection in patients with diseases in which CK2 and OATP1A2 are dysregulated.

  10. Prostate cancer risk and aggressiveness associated with the CYP1B1 4326C/G (Leu432Val) polymorphism: a meta-analysis of 2788 cases and 2968 controls

    PubMed Central

    Yang, Jie; Xu, Dong-Liang; Lu, Qiang; Han, Zhi-Jian; Tao, Jun; Lu, Pei; Wang, Chao; Di, Xiao-Ke; Gu, Min

    2012-01-01

    To derive a precise estimation of the associations between the cytochrome P450 1B1 (CYP1B1) 4326C/G variants and prostate cancer (PCa) risk or aggressiveness, a meta-analysis was performed using all eligible published studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association in seven literature studies with 2788 cases and 2968 controls. In the overall analysis, no significant association was found between the CYP1B1 4326C/G polymorphism and PCa risk, but ethnicity subgroup analyses and a case-source analysis revealed significant associations. The 4326G allele showed a significant association with increased PCa risk in Asians (OR=1.52, 95% CI: 1.20–1.92), and significant associations were also observed in a heterozygote comparison (OR=1.40, 95% CI: 1.03–1.89), a homozygote comparison (OR=2.38, 95% CI: 1.31–4.33) and in a dominant genetic model (OR=1.52, 95% CI: 1.14–2.01). Moreover, the 4326G allele was also significantly correlated with an increased risk of sporadic PCa (OR=1.13, 95% CI: 1.04–1.24), and significant associations were observed in a heterozygote comparison (OR=1.16, 95% CI: 1.02–1.33), a homozygote comparison (OR=1.24, 95% CI: 1.03–1.49) and a dominant genetic model (OR=1.19, 95% CI: 1.05–1.34). The overall analyses and all subgroup analyses showed no significant association between the 4326C/G polymorphism and PCa aggressiveness. Our meta-analysis showed that CYP1B1 4326G allele is significantly associated with an increased PCa risk in Asians and in sporadic PCa cases. PMID:22504876

  11. Chlorophyllin significantly reduces benzo[a]pyrene [BP]-DNA adduct formation and alters Cytochrome P450 1A1 and 1B1 expression and EROD activity in normal human mammary epithelial cells (NHMECs)

    PubMed Central

    Keshava, Channa; Divi, Rao L.; Einem, Tracey L.; Richardson, Diana L.; Leonard, Sarah L.; Keshava, Nagalakshmi; Poirier, Miriam C.; Weston, Ainsley

    2008-01-01

    We hypothesized that chlorophyllin (CHLN) would reduce BP-DNA adduct levels. Using NHMECs exposed to 4 μM BP for 24 hr in the presence or absence of 5 μM CHLN, we measured BP-DNA adducts by chemiluminescence immunoassay (CIA). The protocol included the following experimental groups: BP alone, BP given simultaneously with CHLN (BP+CHLN) for 24 hr, CHLN given for 24 hr followed by BP for 24 hr (preCHLN, postBP), and CHLN given for 48 hr with BP added for the last 24 hr (preCHLN, postBP+CHLN). Incubation with CHLN decreased BPdG levels in all groups, with 87 % inhibition in the preCHLN, postBP+CHLN group. To examine metabolic mechanisms, we monitored expression by Affymetrix microarray (U133A), and found BP-induced up-regulation of CYP1A1 and CYP1B1 expression, as well as up-regulation of groups of interferon-inducible, inflammation and signal transduction genes. Incubation of cells with CHLN and BP in any combination decreased expression of many of these genes. Using real time PCR (RT-PCR) the maximal inhibition of BP-induced gene expression, >85% for CYP1A1 and >70% for CYP1B1, was observed in the preCHLN, postBP+CHLN group. To explore the relationship between transcription and enzyme activity, the ethoxyresorufin-O-deethylase (EROD) assay was used to measure the combined CYP1A1 and CYP1B1 activities. BP exposure caused the EROD levels to double, compared to the unexposed controls. The CHLN-exposed groups all showed EROD levels similar to the unexposed controls. Therefore, the addition of CHLN to BP-exposed cells reduced BPdG formation and CYP1A1 and CYP1B1 expression, but EROD activity was not significantly reduced. PMID:19152381

  12. Prostate cancer risk and aggressiveness associated with the CYP1B1 4326C/G (Leu432Val) polymorphism: a meta-analysis of 2788 cases and 2968 controls.

    PubMed

    Yang, Jie; Xu, Dong-Liang; Lu, Qiang; Han, Zhi-Jian; Tao, Jun; Lu, Pei; Wang, Chao; Di, Xiao-Ke; Gu, Min

    2012-07-01

    To derive a precise estimation of the associations between the cytochrome P450 1B1 (CYP1B1) 4326C/G variants and prostate cancer (PCa) risk or aggressiveness, a meta-analysis was performed using all eligible published studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association in seven literature studies with 2788 cases and 2968 controls. In the overall analysis, no significant association was found between the CYP1B1 4326C/G polymorphism and PCa risk, but ethnicity subgroup analyses and a case-source analysis revealed significant associations. The 4326G allele showed a significant association with increased PCa risk in Asians (OR=1.52, 95% CI: 1.20-1.92), and significant associations were also observed in a heterozygote comparison (OR=1.40, 95% CI: 1.03-1.89), a homozygote comparison (OR=2.38, 95% CI: 1.31-4.33) and in a dominant genetic model (OR=1.52, 95% CI: 1.14-2.01). Moreover, the 4326G allele was also significantly correlated with an increased risk of sporadic PCa (OR=1.13, 95% CI: 1.04-1.24), and significant associations were observed in a heterozygote comparison (OR=1.16, 95% CI: 1.02-1.33), a homozygote comparison (OR=1.24, 95% CI: 1.03-1.49) and a dominant genetic model (OR=1.19, 95% CI: 1.05-1.34). The overall analyses and all subgroup analyses showed no significant association between the 4326C/G polymorphism and PCa aggressiveness. Our meta-analysis showed that CYP1B1 4326G allele is significantly associated with an increased PCa risk in Asians and in sporadic PCa cases.

  13. Design, synthesis, and biological evaluation of novel (1-thioxo-1,2,3,4-tetrahydro-β-carbolin-9-yl)acetic acids as selective inhibitors for AKR1B1.

    PubMed

    Minehira, Daisuke; Takeda, Daisuke; Urata, Hirokazu; Kato, Atsushi; Adachi, Isao; Wang, Xu; Matsuya, Yuji; Sugimoto, Kenji; Takemura, Mayuko; Endo, Satoshi; Matsunaga, Toshiyuki; Hara, Akira; Koseki, Jun; Narukawa, Kayo; Hirono, Shuichi; Toyooka, Naoki

    2012-01-01

    New substituted (1-thioxo-1,2,3,4-tetrahydro-β-carbolin-9-yl)acetic acids were designed as the inhibitor of AKR1B1 based upon the structure of rhetsinine, a minor alkaloidal component of Evodia rutaecarpa, and twenty derivatives were synthesized and evaluated. The most active compound of the series was (2-benzyl-6-methoxy-1-thioxo-1,2,3,4-tetrahydro-β-carbolin-9-yl)acetic acid (7m), which showed comparable inhibitory activity for AKR1B1 (IC(50)=0.15μM) with clinically used epalrestat (IC(50)=0.1μM). In the view of activity and selectivity, the most potent compound was (2-benzyl-6-carboxy-1-thioxo-1,2,3,4-tetrahydro-β-carbolin-9-yl)acetic acid (7t), which showed strong inhibitory effect (IC(50)=0.17μM) and very high selectivity for AKR1B1 against AKR1A1 (311:1) and AKR1B10 (253:1) compared with epalrestat.

  14. Differences in 4-hydroxyestradiol levels in leukocytes are related to CYP1A1(∗)2C, CYP1B1(∗)3 and COMT Val158Met allelic variants.

    PubMed

    Martínez-Ramírez, O C; Pérez-Morales, R; Petrosyan, P; Castro-Hernández, C; Gonsebatt, M E; Rubio, J

    2015-10-01

    Exposure to estrogen and its metabolites, including catechol estrogens (CEs) and catechol estrogen quinones (CE-Qs) is closely related to breast cancer. Polymorphisms of the genes involved in the catechol estrogens metabolism pathway (CEMP) have been shown to affect the production of CEs and CE-Qs. In this study, we measured the induction of CYP1A1, CYP1B1, COMT, and GSTP1 by 17β-estradiol (17β-E2) in leukocytes with CYP1A1(∗)2C, CYP1B1(∗)3, COMT Val158Met and GSTP1 Ile105Val polymorphisms by semi quantitative RT-PCR and compared the values to those of leukocytes with wild type alleles; we also compared the differences in formation of 4- hydroxyestradiol (4-OHE2) and DNA-adducts. The data show that in the leukocytes with mutant alleles treatment with 17β-E2 up-regulates CYP1A1 and CYP1B1 and down-regulates COMT mRNA levels, resulting in major increments in 4-OHE2 levels compared to leukocytes with wild-type alleles. Therefore, we propose induction levels of gene expression and intracellular 4-OHE2 concentrations associated with allelic variants in response to exposure of 17β-E2 as a noninvasive biomarker that can help determine the risk of developing non-hereditary breast cancer in women.

  15. Utility of Oatp1a/1b-knockout and OATP1B1/3-humanized mice in the study of OATP-mediated pharmacokinetics and tissue distribution: case studies with pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein.

    PubMed

    Higgins, J William; Bao, Jing Q; Ke, Alice B; Manro, Jason R; Fallon, John K; Smith, Philip C; Zamek-Gliszczynski, Maciej J

    2014-01-01

    Although organic anion transporting polypeptide (OATP)-mediated hepatic uptake is generally conserved between rodents and humans at a gross pharmacokinetic level, the presence of three major hepatic OATPs with broad overlap in substrate and inhibitor affinity, and absence of rodent-human orthologs preclude clinical translation of single-gene knockout/knockin findings. At present, changes in pharmacokinetics and tissue distribution of pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein were studied in oatp1a/1b-knockout mice lacking the three major hepatic oatp isoforms, and in knockout mice with liver-specific knockin of human OATP1B1 or OATP1B3. Relative to wild-type controls, oatp1a/1b-knockout mice exhibited 1.6- to 19-fold increased intravenous and 2.1- to 115-fold increased oral drug exposure, due to 33%-75% decreased clearance, 14%-60% decreased volume of distribution, and ≤74-fold increased oral bioavailability, with the magnitude of change depending on the contribution of oatp1a/1b to pharmacokinetics. Hepatic drug distribution was 4.2- to 196-fold lower in oatp1a/1b-knockout mice; distributional attenuation was less notable in kidney, brain, cardiac, and skeletal muscle. Knockin of OATP1B1 or OATP1B3 partially restored control clearance, volume, and bioavailability values (24%-142% increase, ≤47% increase, and ≤77% decrease vs. knockout, respectively), such that knockin pharmacokinetic profiles were positioned between knockout and wild-type mice. Consistent with liver-specific humanization, only hepatic drug distribution was partially restored (1.3- to 6.5-fold increase vs. knockout). Exposure and liver distribution changes in OATP1B1-humanized versus knockout mice predicted the clinical impact of OATP1B1 on oral exposure and contribution to human hepatic uptake of statins within 1.7-fold, but only after correcting for human/humanized mouse liver relative protein expression factor (OATP1B1 = 2.2, OATP1B3 = 0.30).

  16. 2,3,7, 8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)-MEDIATED OXIDATIVE STRESS IN FEMALE CYP1A-2 KNOCKOUT (CYP1A2-/-) MICE

    EPA Science Inventory

    2,3,7,8-Tetrachlordibenzo-p-dioxin (TCDD)-Mediated Oxidative Stress in Female CYP1A2 Knockout (CYP1A2-/-) Mice

    Deborah Burgin1, Janet Diliberto2, Linda Birnbaum2
    1UNC Toxicology; 2USEPA/ORD/NHEERL, RTP, NC

    Most of the effects due to TCDD exposure are mediated via...

  17. Cytochrome P450 1A2 (CYP1A2) activity and risk factors for breast cancer: a cross-sectional study

    PubMed Central

    Hong, Chi-Chen; Tang, Bing-Kou; Hammond, Geoffrey L; Tritchler, David; Yaffe, Martin; Boyd, Norman F

    2004-01-01

    Introduction Breast cancer risk may be determined by various genetic, metabolic, and lifestyle factors that alter sex hormone metabolism. Cytochrome P450 1A2 (CYP1A2) is responsible for the metabolism of estrogens and many exogenous compounds, including caffeine. Methods In a cross-sectional study of 146 premenopausal and 149 postmenopausal women, we examined the relationships between CYP1A2 activity and known or suspected risk factors for breast cancer. Blood levels of sex hormones, lipids, and growth factors were measured. In vivo CYP1A2 activity was assessed by measuring caffeine metabolites in urine. Stepwise and maximum R regression analyses were used to identify covariates related to CYP1A2 activity after adjustment for ethnicity. Results In both menopausal groups CYP1A2 activity was positively related to smoking and levels of sex hormone binding globulin. In premenopausal women, CYP1A2 activity was also positively related to insulin levels, caffeine intake, age, and plasma triglyceride levels, and negatively related with total cholesterol levels and body mass index. In postmenopausal women CYP1A2 activity was positively associated with insulin-like growth factor-1, and negatively associated with plasma triglyceride, high-density lipoprotein cholesterol, and age at menarche. Conclusion These results suggest that CYP1A2 activity is correlated with hormones, blood lipids, and lifestyle factors associated with breast cancer risk, although some of the observed associations were contrary to hypothesized directions and suggest that increased CYP1A2 function may be associated with increased risk for breast cancer. PMID:15217502

  18. A genetic polymorphism in coumarin 7-hydroxylation: Sequence of the human CYP2A genes and identification of variant CYP2A6 alleles

    SciTech Connect

    Fernandez-Salguero, P.; Hoffman, S.M.G.; Mohrenweiser, H.

    1995-09-01

    A group of human cytochrome P450 genes encompassing the CYP2A, CYP2B, and CYP2F subfamilies were cloned and assembled into a 350-kb contig localized on the long arm of chromosome 19. Three complete CYP2A genes - CYP2A6, CYP2A7, and CYP2A13 - plus two pseudogenes truncated after exon 5 were identified and sequenced. A variant CYP2A6 allele that differed from the corresponding CYP2A6 and CYP2A7 cDNAs previously sequenced was found and was designated CYP2A6{nu}2. Sequence differences in the CY-P2A6{nu}2 gene are restricted to regions encompassing exons 3, 6, and 8, which bear sequence relatedness with the corresponding exons of the CYP2A7 gene, located downstream and centromeric of CYP2A6{nu}2, suggesting recent gene-conversion events. The sequencing of all the CYP2A genes allowed the design of a PCR diagnostic test for the normal CYP2A6 allele, the CYP2A6{nu}2 allele, and a variant - designated CYP2A6{nu}1 - that encodes an enzyme with a single inactivating amino acid change. These variant alleles were found in individuals who were deficient in their ability to metabolize the CYP2A6 probe drug coumarin. The allelic frequencies of CYP2A6{nu}1 and CYP2A6{nu}2 differed significantly between Caucasian, Asian, and African-American populations. These studies establish the existence of a new cytochrome P450 genetic polymorphism. 30 refs., 4 figs., 2 tabs.

  19. Predictors of Variation in CYP2A6 mRNA, Protein, and Enzyme Activity in a Human Liver Bank: Influence of Genetic and Nongenetic Factors.

    PubMed

    Tanner, Julie-Anne; Prasad, Bhagwat; Claw, Katrina G; Stapleton, Patricia; Chaudhry, Amarjit; Schuetz, Erin G; Thummel, Kenneth E; Tyndale, Rachel F

    2017-01-01

    Cytochrome P450 2A6 CYP2A6: metabolizes several clinically relevant substrates, including nicotine, the primary psychoactive component in cigarette smoke. Smokers vary widely in their rate of inactivation and clearance of nicotine, altering numerous smoking phenotypes. We aimed to characterize independent and shared impact of genetic and nongenetic sources of variation in CYP2A6 mRNA, protein, and enzyme activity in a human liver bank (n = 360). For the assessment of genetic factors, we quantified levels of CYP2A6, cytochrome P450 oxidoreductase (POR), and aldo-keto reductase 1D1 (AKR1D1) mRNA, and CYP2A6 and POR proteins. CYP2A6 enzyme activity was determined through measurement of cotinine formation from nicotine and 7-hydroxycoumarin formation from coumarin. Donor DNA was genotyped for CYP2A6, POR, and AKR1D1 genetic variants. Nongenetic factors assessed included gender, age, and liver disease. CYP2A6 phenotype measures were positively correlated to each other (r values ranging from 0.47-0.88, P < 0.001). Female donors exhibited higher CYP2A6 mRNA expression relative to males (P < 0.05). Donor age was weakly positively correlated with CYP2A6 protein (r = 0.12, P < 0.05) and activity (r = 0.20, P < 0.001). CYP2A6 reduced-function genotypes, but not POR or AKR1D1 genotypes, were associated with lower CYP2A6 protein (P < 0.001) and activity (P < 0.01). AKR1D1 mRNA was correlated with CYP2A6 mRNA (r = 0.57, P < 0.001), protein (r = 0.30, P < 0.001), and activity (r = 0.34, P < 0.001). POR protein was correlated with CYP2A6 activity (r = 0.45, P < 0.001). Through regression analyses, we accounted for 17% (P < 0.001), 37% (P < 0.001), and 77% (P < 0.001) of the variation in CYP2A6 mRNA, protein, and activity, respectively. Overall, several independent and shared sources of variation in CYP2A6 activity in vitro have been identified, which could translate to variable hepatic clearance of nicotine.

  20. Human organic anion transporting polypeptide 1A2 (OATP1A2) mediates cellular uptake of all-trans-retinol in human retinal pigmented epithelial cells

    PubMed Central

    Chan, Ting; Zhu, Ling; Madigan, Michele C; Wang, Ke; Shen, Weiyong; Gillies, Mark C; Zhou, Fanfan

    2015-01-01

    Background and Purpose Vision depends on retinoid exchange between the retinal pigment epithelium (RPE) and photoreceptors. Defects in any step of the canonical visual cycle can lead to retinal degenerations. All-trans-retinol (atROL) plays an important role in visual signal transduction. However, how atROL enters human RPE from the apical membrane remains unclear. This study investigated the role of human organic anion transporting polypeptide 1A2 (OATP1A2) in atROL uptake in human RPE. Experimental Approach Immunoblotting and immunostaining elucidated the expression and localization of OATP1A2 in human RPE. Transporter functional studies were conducted to assess the interaction of OATP1A2 with atROL. Key Results Our study revealed OATP1A2 is expressed in human RPE, mainly at the apical membrane. Our data also indicated atROL inhibited the uptake of the typical OATP1A2 substrate, oestrone-3-sulfate (E3S), in over-expressing cells. Studies on the uptake of 3H-atROL in these over-expressing cells revealed atROL is a substrate of OATP1A2. We confirmed these findings in human primary RPE cells. The transport of E3S and atROL was significantly reduced in human primary RPE cells with OATP1A2 siRNA silencing. Conclusion and Implications Our data provides the first evidence of OATP1A2 expression in human RPE and more importantly, its novel role in the cellular uptake of atROL, which might be essential to the proper functioning of the canonical visual cycle. Our findings contribute to the understanding of the molecular mechanisms involved in retinoid transport between the RPE and photoreceptors and provide novel insights into potential pharmaceutical interventions for visual cycle disruption associated with retinal degenerations. PMID:25560245

  1. Association between exposure-relevant polymorphisms in CYP1B1, EPHX1, NQO1, GSTM1, GSTP1 and GSTT1 and risk of colorectal cancer in a Czech population.

    PubMed

    Hlavata, Ivona; Vrana, David; Smerhovsky, Zdenek; Pardini, Barbara; Naccarati, Alessio; Vodicka, Pavel; Novotny, Jan; Mohelnikova-Duchonova, Beatrice; Soucek, Pavel

    2010-11-01

    Associations of functional single nucleotide polymorphisms in cytochrome P450 1B1, epoxide hydrolase 1, NAD(P)H:quinone oxidoreductase 1, glutathione S-transferase Pi-1 and deletions of glutathione S-transferases Mu-1 and θ-1 with colorectal cancer risk were investigated in a hospital-based case-control study on 495 matched pairs of Czech Caucasians. Polymorphisms were assessed by polymerase chain reaction restriction fragment length polymorphism-based methods, allele-specific multiplex and allelic discrimination by real-time polymerase chain reaction. Carriers of variant Ser allele in codon 453 of cytochrome P450 1B1 (rs1800440) were at a significantly lower risk of colorectal cancer compared to carriers of the wild-type allele (adjusted odds ratio, aOR=0.68, CI=0.51-0.89, p=0.006). The combination of polymorphisms in codons 453 and 432 (rs1056836) of cytochrome P450 1B1 further increased the protective effect (aOR=0.53, CI=0.34-0.83, p=0.005). The glutathione S-transferase Mu-1 deletion was associated with a moderately elevated colorectal cancer risk (aOR=1.30, CI=1.01-1.68, p=0.044). Combination of glutathione S-transferase Mu-1 and θ-1 deletion was associated with a significantly higher colorectal cancer risk compared to the presence of both full-length genes (aOR=1.58, CI=1.01-2.47, p=0.044). Genetic polymorphisms in glutathione S-transferase Pi-1, NAD(P)H:quinone oxidoreductase 1, epoxide hydrolase 1 and deduced epoxid hydrolase 1 activity did not modify the risk of colorectal cancer. These results provide further evidence that interaction between metabolic gene variants contributes to colorectal carcinogenesis.

  2. Prenatal 3,3',4,4',5-pentachlorobiphenyl exposure modulates induction of rat hepatic CYP 1A1, 1B1, and AhR by 7,12-dimethylbenz[a]anthracene

    SciTech Connect

    Wakui, Shin . E-mail: wakui@azabu-u.ac.jp; Yokoo, Kiyofumi; Takahashi, Hiroyuki; Muto, Tomoko; Suzuki, Yoshihiko; Kanai, Yoshikatsu; Hano, Hiroshi; Furusato, Masakuni; Endou, Hitoshi

    2006-02-01

    We previously reported the finding that prenatal exposure to a relatively low dose of PCB126 increases the rate of DMBA-induced rat mammary carcinoma, while a high dose decreased it. One of the most important factors determining the sensitivity to mammary carcinogenesis is the metabolic stage at administration of the carcinogenic agent. DMBA is a procarcinogen that recruits the host metabolism to yield its ultimate carcinogenic form, and CYP1A1 and CYP1B1 (CYP1) conduct this metabolism. We investigated the hepatic expression of CYP1 and AhR following oral administration of DMBA (100 mg/kg b.w.) (i.g.) to 50-day-old female Sprague-Dawley rats whose dams had been treated (i.g.) with 2.5 ng, 250 ng, 7.5 {mu}g of PCB126/kg or the vehicle on days 13 to 19 post-conception. Real-time quantitative RT-PCR analysis revealed that the prenatal exposure to a relatively low dose of PCB126 (the 250 ng group) prolonged the higher expression of CYP1A1, CYP1B1, and AhR mRNA, while prenatal exposure to a high dose of PCB126 (the 7.5 {mu}g group) prolonged the higher expression of CYP1A1 and AhR mRNA. Western blotting and immunohistochemical analyses were consistent with mRNAs changes. Because DMBA oxidation produces a highly mutagenic metabolite and is finally catalyzed by CYP1B1, a relatively low PCB126 dose might produce the biological character to potentially increase the risk of DMBA-induced mammary carcinoma.

  3. Induction of CYP1A1 and CYP1B1 by benzo(k)fluoranthene and benzo(a)pyrene in T-47D human breast cancer cells: Roles of PAH interactions and PAH metabolites

    SciTech Connect

    Spink, David C. Wu, Susan J.; Spink, Barbara C.; Hussain, Mirza M.; Vakharia, Dilip D.; Pentecost, Brian T.; Kaminsky, Laurence S.

    2008-02-01

    The interactions of polycyclic aromatic hydrocarbons (PAH) and cytochromes P450 (CYP) are complex; PAHs are enzyme inducers, substrates, and inhibitors. In T-47D breast cancer cells, exposure to 0.1 to 1 {mu}M benzo(k)fluoranthene (BKF) induced CYP1A1/1B1-catalyzed 17{beta}-estradiol (E{sub 2}) metabolism, whereas BKF levels greater than 1 {mu}M inhibited E{sub 2} metabolism. Time course studies showed that induction of CYP1-catalyzed E{sub 2} metabolism persisted after the disappearance of BKF or co-exposed benzo(a)pyrene, suggesting that BKF metabolites retaining Ah receptor agonist activity were responsible for prolonged CYP1 induction. BKF metabolites were shown, through the use of ethoxyresorufin O-deethylase and CYP1A1-promoter-luciferase reporter assays to induce CYP1A1/1B1 in T-47D cells. Metabolites formed by oxidation at the C-2/C-3 region of BKF had potencies for CYP1 induction exceeding those of BKF, whereas C-8/C-9 oxidative metabolites were somewhat less potent than BKF. The activities of expressed human CYP1A1 and 1B1 with BKF as substrate were investigated by use of HPLC with fluorescence detection, and by GC/MS. The results showed that both enzymes efficiently catalyzed the formation of 3-, 8-, and 9-OHBKF from BKF. These studies indicate that the inductive effects of PAH metabolites as potent CYP1 inducers are likely to be additional important factors in PAH-CYP interactions that affect metabolism and bioactivation of other PAHs, ultimately modulating PAH toxicity and carcinogenicity.

  4. Cytogenetic damage in Turkish coke oven workers exposed to polycyclic aromatic hydrocarbons: Association with CYP1A1, CYP1B1, EPHX1, GSTM1, GSTT1, and GSTP1 gene polymorphisms.

    PubMed

    Ada, Ahmet Oguz; Demiroglu, Canan; Yilmazer, Meltem; Suzen, Halit Sinan; Demirbag, Ali Eba; Efe, Sibel; Alemdar, Yilmaz; Iscan, Mumtaz; Burgaz, Sema

    2013-09-01

    The aim of this study was to determine the frequencies of chromosomal aberrations (CA) and cytochalasin-blocked micronuclei (CBMN) in peripheral blood lymphocytes from Turkish coke oven workers and the influence of CYP1A1, CYP1B1, EPHX1, GSTM1, GSTT1, and GSTP1 gene polymorphisms on these biomarkers. Cytogenetic analysis showed that occupational exposure significantly increased the CA and CBMN frequencies. Gene polymorphisms, on the other hand, did not affect CA or CBMN in either exposed or control subjects. However, due to the limited sample size, our findings need to be verified in future studies with a larger sample.

  5. Single amino acid mutations, but not common polymorphisms, decrease the activity of CYP1B1 against (-)benzo[a]pyrene-7R-trans-7,8-dihydrodiol.

    PubMed

    Mammen, Jennifer S; Pittman, Gary S; Li, Ying; Abou-Zahr, Fadi; Bejjani, Bassem A; Bell, Douglas A; Strickland, Paul T; Sutter, Thomas R

    2003-07-01

    Genetic differences that underlie inter-individual variation in the metabolism of common carcinogens are important potential sources of cancer susceptibility. Cytochrome P450 1B1 (CYP1B1), a central enzyme in the activation of the ubiquitous environmental carcinogen benzo[a]pyrene (B[a]P), has several genetic variants. This study investigated six rare mutations and four common polymorphisms for their effects on B[a]P metabolism. Five missense mutations associated with congenital glaucoma (Gly61Glu, Gly365Trp, Asp374Asn, Pro437Leu and Arg469Tryp) dramatically decreased the capacity of CYP1B1 to convert (-)benzo[a]pyrene-7R-trans-7,8-dihyrodiol (B[a]P-7,8-diol) to (+/-)benzo[a]pyrene-r-7,t-8-dihydrodiol-9,10-epoxides. These five mutations resulted in enzymes with 3-12% of normal activity when assayed in vitro using an Saccharomyces cerevisiae microsomal expression system. A 10 bp deletion mutation produced no detectable protein or activity. In contrast, proteins containing all possible combinations of four common single nucleotide polymorphisms (Arg48Gly, Ala199Ser, Val432Leu, Asn453Ser) had modest effects on B[a]P-7,8-diol metabolism. Michaelis-Menten analysis suggested that two alleles, Arg48, Ala119, Val432, Ser453 (RAVS) and Arg48, Ala119, Leu432, Ser453 (RALS), have KM values 2-fold lower than Arg48, Ala119, Val432, Ser453 (RAVN): 1.4+/-0.3 and 1.3+/-0.4 microM, respectively, compared with 2.8+/-0.8 microM (P<0.05). However, these differences could not be confirmed with direct measurements of rate at low substrate concentration. There were no significant differences for either of two other kinetic parameters, kcat or kcat/KM. Allele frequency analysis in three populations reveals the Ser453 variant is rare among those of Asian (<1%) and African ancestry (<4%), and more common in individuals of European ancestry (16%). Haplotypes containing the Ser453 variant were uncommon; only RALS was detectable in our small populations. The RALS allele occurred between 0

  6. Chlorophyllin significantly reduces benzo[a]pyrene-DNA adduct formation and alters cytochrome P450 1A1 and 1B1 expression and EROD activity in normal human mammary epithelial cells.

    PubMed

    Keshava, Channa; Divi, Rao L; Einem, Tracey L; Richardson, Diana L; Leonard, Sarah L; Keshava, Nagalakshmi; Poirier, Miriam C; Weston, Ainsley

    2009-03-01

    We hypothesized that chlorophyllin (CHLN) would reduce benzo[a]pyrene-DNA (BP-DNA) adduct levels. Using normal human mammary epithelial cells (NHMECs) exposed to 4 microM BP for 24 hr in the presence or absence of 5 microM CHLN, we measured BP-DNA adducts by chemiluminescence immunoassay (CIA). The protocol included the following experimental groups: BP alone, BP given simultaneously with CHLN (BP+CHLN) for 24 hr, CHLN given for 24 hr followed by BP for 24 hr (preCHLN, postBP), and CHLN given for 48 hr with BP added for the last 24 hr (preCHLN, postBP+CHLN). Incubation with CHLN decreased BPdG levels in all groups, with 87% inhibition in the preCHLN, postBP+CHLN group. To examine metabolic mechanisms, we monitored expression by Affymetrix microarray (U133A), and found BP-induced up-regulation of CYP1A1 and CYP1B1 expression, as well as up-regulation of groups of interferon-inducible, inflammation and signal transduction genes. Incubation of cells with CHLN and BP in any combination decreased expression of many of these genes. Using reverse transcription real time PCR (RT-PCR) the maximal inhibition of BP-induced gene expression, >85% for CYP1A1 and >70% for CYP1B1, was observed in the preCHLN, postBP+CHLN group. To explore the relationship between transcription and enzyme activity, the ethoxyresorufin-O-deethylase (EROD) assay was used to measure the combined CYP1A1 and CYP1B1 activities. BP exposure caused the EROD levels to double, when compared with the unexposed controls. The CHLN-exposed groups all showed EROD levels similar to the unexposed controls. Therefore, the addition of CHLN to BP-exposed cells reduced BPdG formation and CYP1A1 and CYP1B1 expression, but EROD activity was not significantly reduced.

  7. PDZK1 and NHERF1 Regulate the Function of Human Organic Anion Transporting Polypeptide 1A2 (OATP1A2) by Modulating Its Subcellular Trafficking and Stability

    PubMed Central

    Zheng, Jian; Chan, Ting; Cheung, Florence Shin Gee; Zhu, Ling; Murray, Michael; Zhou, Fanfan

    2014-01-01

    The human organic anion transporting polypeptide 1A2 (OATP1A2) is an important membrane protein that mediates the cellular influx of various substances including drugs. Previous studies have shown that PDZ-domain containing proteins, especially PDZK1 and NHERF1, regulate the function of related membrane transporters in other mammalian species. This study investigated the role of PDZK1 and NHERF1 in the regulation of OATP1A2 in an in vitro cell model. Transporter function and protein expression were assessed in OATP1A2-transfected HEK-293 cells that co-expressed PDZK1 or NHERF1. Substrate (estrone-3-sulfate) uptake by OATP1A2 was significantly increased to ∼1.6- (PDZK1) and ∼1.8- (NHERF1) fold of control; this was dependent on the putative PDZ-binding domain within the C-terminus of OATP1A2. The functional increase of OATP1A2 following PDZK1 or NHERF1 over-expression was associated with increased transporter expression at the plasma membrane and in the whole cell, and was reflected by an increase in the apparent maximal velocity of estrone-3-sulfate uptake (Vmax: 138.9±4.1 (PDZK1) and 181.4±16.7 (NHERF1) versus 55.5±3.2 pmol*(µg*4 min)−1 in control; P<0.01). Co-immunoprecipitation analysis indicated that the regulatory actions of PDZK1 and NHERF1 were mediated by direct interaction with OATP1A2 protein. In further experiments PDZK1 and NHERF1 modulated OATP1A2 expression by decreasing its internalization in a clathrin-dependent (but caveolin-independent) manner. Additionally, PDZK1 and NHERF1 enhanced the stability of OATP1A2 protein in HEK-293 cells. The present findings indicated that PDZK1 and NHERF1 regulate the transport function of OATP1A2 by modulating protein internalization via a clathrin-dependent pathway and by enhancing protein stability. PMID:24728453

  8. PDZK1 and NHERF1 regulate the function of human organic anion transporting polypeptide 1A2 (OATP1A2) by modulating its subcellular trafficking and stability.

    PubMed

    Zheng, Jian; Chan, Ting; Cheung, Florence Shin Gee; Zhu, Ling; Murray, Michael; Zhou, Fanfan

    2014-01-01

    The human organic anion transporting polypeptide 1A2 (OATP1A2) is an important membrane protein that mediates the cellular influx of various substances including drugs. Previous studies have shown that PDZ-domain containing proteins, especially PDZK1 and NHERF1, regulate the function of related membrane transporters in other mammalian species. This study investigated the role of PDZK1 and NHERF1 in the regulation of OATP1A2 in an in vitro cell model. Transporter function and protein expression were assessed in OATP1A2-transfected HEK-293 cells that co-expressed PDZK1 or NHERF1. Substrate (estrone-3-sulfate) uptake by OATP1A2 was significantly increased to ∼1.6- (PDZK1) and ∼1.8- (NHERF1) fold of control; this was dependent on the putative PDZ-binding domain within the C-terminus of OATP1A2. The functional increase of OATP1A2 following PDZK1 or NHERF1 over-expression was associated with increased transporter expression at the plasma membrane and in the whole cell, and was reflected by an increase in the apparent maximal velocity of estrone-3-sulfate uptake (V(max): 138.9±4.1 (PDZK1) and 181.4±16.7 (NHERF1) versus 55.5±3.2 pmol*(µg*4 min)⁻¹ in control; P<0.01). Co-immunoprecipitation analysis indicated that the regulatory actions of PDZK1 and NHERF1 were mediated by direct interaction with OATP1A2 protein. In further experiments PDZK1 and NHERF1 modulated OATP1A2 expression by decreasing its internalization in a clathrin-dependent (but caveolin-independent) manner. Additionally, PDZK1 and NHERF1 enhanced the stability of OATP1A2 protein in HEK-293 cells. The present findings indicated that PDZK1 and NHERF1 regulate the transport function of OATP1A2 by modulating protein internalization via a clathrin-dependent pathway and by enhancing protein stability.

  9. Mechanism-based inhibition of cytochrome P450 (CYP)2A6 by chalepensin in recombinant systems, in human liver microsomes and in mice in vivo

    PubMed Central

    Ueng, Yune-Fang; Chen, Chien-Chih; Chung, Yu-Ting; Liu, Tsung-Yun; Chang, Yu-Ping; Lo, Wei-Sheng; Murayama, Norie; Yamazaki, Hiroshi; Souček, Pavel; Chau, Gar-Yang; Chi, Chin-Wen; Chen, Ruei-Ming; Li, Ding-Tzai

    2011-01-01

    BACKGROUND AND PURPOSE Chalepensin is a pharmacologically active furanocoumarin compound found in rue, a medicinal herb. Here we have investigated the inhibitory effects of chalepensin on cytochrome P450 (CYP) 2A6 in vitro and in vivo. EXPERIMENTAL APPROACH Mechanism-based inhibition was studied in vitro using human liver microsomes and bacterial membranes expressing genetic variants of human CYP2A6. Effects in vivo were studied in C57BL/6J mice. CYP2A6 activity was assayed as coumarin 7-hydroxylation (CH) using HPLC and fluorescence measurements. Metabolism of chalepensin was assessed with liquid chromatography/mass spectrometry (LC/MS). KEY RESULTS CYP2A6.1, without pre-incubation with NADPH, was competitively inhibited by chalepensin. After pre-incubation with NADPH, inhibition by chalepensin was increased (IC50 value decreased by 98%). This time-dependent inactivation (kinact 0.044 min−1; KI 2.64 µM) caused the loss of spectrally detectable P450 content and was diminished by known inhibitors of CYP2A6, pilocarpine or tranylcypromine, and by glutathione conjugation. LC/MS analysis of chalepensin metabolites suggested an unstable epoxide intermediate was formed, identified as the corresponding dihydrodiol, which was then conjugated with glutathione. Compared with the wild-type CYP2A6.1, the isoforms CYP2A6.7 and CYP2A6.10 were less inhibited. In mouse liver microsomes, pre-incubation enhanced inhibition of CH activity. Oral administration of chalepensin to mice reduced hepatic CH activity ex vivo. CONCLUSIONS AND IMPLICATIONS Chalepensin was a substrate and a mechanism-based inhibitor of human CYP2A6. Formation of an epoxide could be a key step in this inactivation. ‘Poor metabolizers’ carrying CYP2A6*7 or *10 may be less susceptible to inhibition by chalepensin. Given in vivo, chalepensin decreased CYP2A activity in mice. PMID:21418183

  10. The crystal structure of 6-(4-chloro­phen­yl)-2-(4-methyl­benz­yl)imidazo[2,1-b][1,3,4]thia­diazole-5-carbaldehyde

    PubMed Central

    Sowmya, A.; Anil Kumar, G. N.; Kumar, Sujeet; Karki, Subhas S.

    2016-01-01

    In the title imidazo[2,1-b][1,3,4]thia­diazole derivative, C19H14ClN3OS, the 4-methyl­benzyl and chloro­phenyl rings are inclined to the planar imidazo[2,1-b][1,3,4]thia­diazole moiety (r.m.s. deviation = 0.012 Å) by 64.5 (1) and 3.7 (1)°, respectively. The mol­ecular structure is primarily stabilized by a strong intra­molecular C—H⋯O hydrogen bond, leading to the formation of a pseudo-seven-membered S(7) ring motif, and a short intra­molecular C—H⋯N contact forming an S(5) ring motif. In the crystal, mol­ecules are linked by pairs of C—H⋯S hydrogen bonds, forming inversion dimers. The dimers are linked by C—H⋯O and C—H⋯π inter­actions, forming chains propagating along [110]. PMID:27746941

  11. Diversity of selective environmental substrates for human cytochrome P450 2A6: alkoxyethers, nicotine, coumarin, N-nitrosodiethylamine, and N-nitrosobenzylmethylamine.

    PubMed

    Le Gal, Annabelle; Dréano, Yvonne; Lucas, Danièle; Berthou, François

    2003-09-15

    Cytochrome P450 2A6 constitutes 5-10% of the total microsomal CYPs of human liver. Although CYP2A6 is the major coumarin 7-hydroxylase, other known substrates of CYP2A6 include many toxicants and precarcinogens. The chemical structure diversity of these substrates raises the question of their selectivity. Thus, kinetic parameters were determined for the hydroxylation of five substrates of diverse chemical structures known to be selective for cytochrome P450 2A6: methyl tert-butyl ether (MTBE), nicotine, coumarin, N-nitrosobenzylmethylamine (NBzMA), and N-nitrosodiethylamine (NDEA). Sources of enzymes were either human liver microsomes or heterologously expressed CYPs. Coumarin was shown to be the substrate with the highest affinity, followed by NDEA, nicotine, NBzMA, and MTBE. Variability of CYP2A6 catalytic activities in human liver was between 24-fold for MTBE to sevenfold for coumarin, while CYP2A6 content varied 68-fold in human liver microsomes. These five catalytic activities were highly significantly correlated between them and with hepatic CYP2A6 content. The most selective chemical inhibitor of these five substrates was shown to be 8-methoxypsoralen. Based upon chemical inhibition of the enzymatic activities of pure recombinant human CYPs, it cannot be totally excluded that P450s other than CYP2A6, especially CYP2E1, are involved, although to a lesser extent, in NDEA and NBzMA metabolism. In conclusion, the prototype probes for CYP2A6 phenotyping are coumarin and nicotine.

  12. Evidence for Concurrent Effects of Exposure to Environmental Cadmium and Lead on Hepatic CYP2A6 Phenotype and Renal Function Biomarkers in Nonsmokers

    PubMed Central

    Satarug, Soisungwan; Nishijo, Muneko; Ujjin, Pailin; Vanavanitkun, Yuvaree; Baker, Jason R.; Moore, Michael R.

    2004-01-01

    We examined the interrelationships between phenotype of hepatic cytochrome P450 2A6 (CYP2A6), nephropathy, and exposure to cadmium and lead in a group of 118 healthy Thai men and women who had never smoked. Their urinary Cd excretion ranged from 0.05 to 2.36 μg/g creatinine, whereas their urinary Pb excretion ranged from 0.1 to 12 μg/g creatinine. Average age and Cd burden of women and men did not differ. Women, however, on average showed a 46% higher urinary Pb excretion (p < 0.001) and lower zinc status, suggested by lower average serum Zn and urinary Zn excretion compared with those in men. Cd-linked nephropathy was detected in both men and women. However, Pb-linked nephropathy was seen only in women, possibly because of higher Pb burden coupled with lower protective factors, notably of Zn (p < 0.001), in women compared with men. In men, Pb burden showed a negative association with CYP2A6 activity (adjusted β= −0.29, p = 0.003), whereas Cd burden showed a positive association with CYP2A6 activity (adjusted β= 0.38, p = 0.001), suggesting opposing effects of Cd and Pb on hepatic CYP2A6 phenotype. The weaker correlation between Cd burden CYP2A6 activity in women despite similarity in Cd burden between men and women is consistent with opposing effects of Pb and Cd on hepatic CYP2A6 phenotypic expression. A positive correlation between Cd-linked nephropathy (urinary N-acetyl-β-d-glucosaminidase excretion) and CYP2A6 activity in men (r = 0.39, p = 0.002) and women (r = 0.37, p = 0.001) suggests that Cd induction of hepatic CYP2A6 expression and Cd-linked nephropathy occurred simultaneously. PMID:15531436

  13. Genetic determinants of CYP2A6 activity across racial/ethnic groups with different risks of lung cancer and effect on their smoking intensity.

    PubMed

    Park, Sungshim L; Tiirikainen, Maarit I; Patel, Yesha M; Wilkens, Lynne R; Stram, Daniel O; Le Marchand, Loic; Murphy, Sharon E

    2016-03-01

    Genetic variation in cytochrome P450 2A6 (CYP2A6) gene is the primary contributor to the intraindividual and interindividual differences in nicotine metabolism and has been found to influence smoking intensity. However, no study has evaluated the relationship between CYP2A6 genetic variants and the CYP2A6 activity ratio (total 3-hydroxycotinine/cotinine) and their influence on smoking intensity [total nicotine equivalents (TNE)], across five racial/ethnic groups found to have disparate rates of lung cancer. This study genotyped 10 known functional CYP2A6 genetic or copy number variants in 2115 current smokers from the multiethnic cohort study [African Americans (AA) = 350, Native Hawaiians (NH) = 288, Whites = 413, Latinos (LA) = 437 and Japanese Americans (JA) = 627] to conduct such an investigation. Here, we found that LA had the highest CYP2A6 activity followed by Whites, AA, NH and JA, who had the lowest levels. Adjusting for age, sex, race/ethnicity and body mass index, we found that CYP2A6 diplotypes were predictive of TNE levels, particularly in AA and JA (P trend < 0.0001). However, only in JA did the association remain after accounting for cigarettes per day. Also, it is only in this population that the lower activity ratio supports lower TNE levels, carcinogen exposure and thereby lower risk of lung cancer. Despite the association between nicotine metabolism (CYP2A6 activity phenotype and diplotypes) and smoking intensity (TNE), CYP2A6 levels did not correlate with the higher TNE levels found in AA nor the lower TNE levels found in LA, suggesting that other factors may influence smoking dose in these populations. Therefore, further study in these populations is recommended.

  14. Introduction of aromatic ring-containing substituents in cyclic nucleotides is associated with inhibition of toxin uptake by the hepatocyte transporters OATP 1B1 and 1B3.

    PubMed

    Herfindal, Lars; Krakstad, Camilla; Myhren, Lene; Hagland, Hanne; Kopperud, Reidun; Teigen, Knut; Schwede, Frank; Kleppe, Rune; Døskeland, Stein Ove

    2014-01-01

    Analogs of the cyclic nucleotides cAMP and cGMP have been extensively used to mimic or modulate cellular events mediated by protein kinase A (PKA), Exchange protein directly activated by cAMP (Epac), or protein kinase G (PKG). We report here that some of the most commonly used cyclic nucleotide analogs inhibit transmembrane transport mediated by the liver specific organic anion transporter peptides OATP1B1 and OATP1B3, unrelated to actions on Epac, PKA or PKG. Several cAMP analogs, particularly with 8-pCPT-substitution, inhibited nodularin (Nod) induced primary rat hepatocyte apoptosis. Inhibition was not mediated by PKA or Epac, since increased endogenous cAMP, and some strong PKA- or Epac-activating analogs failed to protect cells against Nod induced apoptosis. The cAMP analogs inhibiting Nod induced hepatocyte apoptosis also reduced accumulation of radiolabeled Nod or cholic acid in primary rat hepatocytes. They also inhibited Nod induced apoptosis in HEK293 cells with enforced expression of OATP1B1 or 1B3, responsible for Nod transport into cells. Similar results were found with adenosine analogs, disconnecting the inhibitory effect of certain cAMP analogs from PKA or Epac. The most potent inhibitors were 8-pCPT-6-Phe-cAMP and 8-pCPT-2'-O-Me-cAMP, whereas analogs like 6-MB-cAMP or 8-Br-cAMP did not inhibit Nod uptake. This suggests that the addition of aromatic ring-containing substituents like the chloro-phenyl-thio group to the purines of cyclic nucleotides increases their ability to inhibit the OATP-mediated transport. Taken together, our data show that aromatic ring substituents can add unwanted effects to cyclic nucleotides, and that such nucleotide analogs must be used with care, particularly when working with cells expressing OATP1B1/1B3, like hepatocytes, or intact animals where hepatic metabolism can be an issue, as well as certain cancer cells. On the other hand, cAMP analogs with substituents like bromo, monobutyryl were non-inhibitory, and could be

  15. Maternal and zygotic aldh1a2 activity is required for pancreas development in zebrafish.

    PubMed

    Alexa, Kristen; Choe, Seong-Kyu; Hirsch, Nicolas; Etheridge, Letitiah; Laver, Elizabeth; Sagerström, Charles G

    2009-12-11

    We have isolated and characterized a novel zebrafish pancreas mutant. Mutant embryos lack expression of isl1 and sst in the endocrine pancreas, but retain isl1 expression in the CNS. Non-endocrine endodermal gene expression is less affected in the mutant, with varying degrees of residual expression observed for pdx1, carbA, hhex, prox1, sid4, transferrin and ifabp. In addition, mutant embryos display a swollen pericardium and lack fin buds. Genetic mapping revealed a mutation resulting in a glycine to arginine change in the catalytic domain of the aldh1a2 gene, which is required for the production of retinoic acid from vitamin A. Comparison of our mutant (aldh1a2(um22)) to neckless (aldh1a2(i26)), a previously identified aldh1a2 mutant, revealed similarities in residual endodermal gene expression. In contrast, treatment with DEAB (diethylaminobenzaldehyde), a competitive reversible inhibitor of Aldh enzymes, produces a more severe phenotype with complete loss of endodermal gene expression, indicating that a source of Aldh activity persists in both mutants. We find that mRNA from the aldh1a2(um22) mutant allele is inactive, indicating that it represents a null allele. Instead, the residual Aldh activity is likely due to maternal aldh1a2, since we find that translation-blocking, but not splice-blocking, aldh1a2 morpholinos produce a phenotype similar to DEAB treatment. We conclude that Aldh1a2 is the primary Aldh acting during pancreas development and that maternal Aldh1a2 activity persists in aldh1a2(um22) and aldh1a2(i26) mutant embryos.

  16. Induction of Cyp1a1 and Cyp1b1 and formation of DNA adducts in C57BL/6, Balb/c, and F1 mice following in utero exposure to 3-methylcholanthrene

    SciTech Connect

    Xu Mian; Nelson, Garret B.; Moore, Joseph E.; McCoy, Thomas P.; Dai, Jian; Manderville, Richard A.; Ross, Jeffrey A.; Miller, Mark Steven . E-mail: msmiller@wfubmc.edu

    2005-11-15

    Fetal mice are more sensitive to chemical carcinogens than are adults. Previous studies from our laboratory demonstrated differences in the mutational spectrum induced in the Ki-ras gene from lung tumors isolated from [D2 x B6D2F1]F2 mice and Balb/c mice treated in utero with 3-methylcholanthrene (MC). We thus determined if differences in metabolism, adduct formation, or adduct repair influence strain-specific responses to transplacental MC exposure in C57BL/6 (B6), Balb/c (BC), and reciprocal F1 crosses between these two strains of mice. The induction of Cyp1a1 and Cyp1b1 in fetal lung and liver tissue was determined by quantitative fluorescent real-time PCR. MC treatment caused maximal induction of Cyp1a1 and Cyp1b1 RNA 2-8 h after injection in both organs. RNA levels for both genes then declined in both fetal organs, but a small biphasic, secondary increase in Cyp1a1 was observed specifically in the fetal lung 24-48 h after MC exposure in all four strains. Cyp1a1 induction by MC at 4 h was 2-5 times greater in fetal liver (7000- to 16,000-fold) than fetal lung (2000- to 6000-fold). Cyp1b1 induction in both fetal lung and liver was similar and much lower than that observed for Cyp1a1, with induction ratios of 8- to 18-fold in fetal lung and 10- to 20-fold in fetal liver. The overall kinetics and patterns of induction were thus very similar across the four strains of mice. The only significant strain-specific effect appeared to be the relatively poor induction of Cyp1b1 in the parental strain of B6 mice, especially in fetal lung tissue. We also measured the levels of MC adducts and their disappearance from lung tissue by the P{sup 32} post-labeling assay on gestation days 18 and 19 and postnatal days 1, 4, 11, and 18. Few differences were seen between the different strains of mice; the parental strain of B6 mice had nominally higher levels of DNA adducts 2 (gestation day 19) and 4 (postnatal day 1) days after injection, although this was not statistically

  17. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated oxidative stress in CYP1A2 knockout (CYP1A2-/-) mice.

    PubMed

    Slezak, B P; Diliberto, J J; Birnbaum, L S

    1999-10-22

    The objective of the study was to compare alterations in indicators of oxidative stress following 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure in cytochrome P4501A2 (CYP1A2) knockout mice and their parental lineage strains (C57BL/6N and 129/Sv). This study will aid in determining the role, if any, of CYP1A2 in TCDD-mediated oxidative stress. Formation of thiobarbituric acid-reactive substances (TBARS) as a measurement of lipid peroxidation, production of reactive oxygen species (ROS) via the in vitro reduction of cytochrome c in tissue homogenate, and changes in the biochemical antioxidant glutathione were monitored to determine oxidative stress 7 days following a single oral dose of 25 microg TCDD/kg. TBARS, reduction of cytochrome c, and changes in glutathione demonstrated a similar response in CYP1A2 knockout and parental strains. These data suggest that CYP1A2 does not play a critical role in the acute oxidative stress response following TCDD exposure.

  18. Inhibitory Effects of Green Tea and (-)-Epigallocatechin Gallate on Transport by OATP1B1, OATP1B3, OCT1, OCT2, MATE1, MATE2-K and P-Glycoprotein.

    PubMed

    Knop, Jana; Misaka, Shingen; Singer, Katrin; Hoier, Eva; Müller, Fabian; Glaeser, Hartmut; König, Jörg; Fromm, Martin F

    2015-01-01

    Green tea catechins inhibit the function of organic anion transporting polypeptides (OATPs) that mediate the uptake of a diverse group of drugs and endogenous compounds into cells. The present study was aimed at investigating the effect of green tea and its most abundant catechin epigallocatechin gallate (EGCG) on the transport activity of several drug transporters expressed in enterocytes, hepatocytes and renal proximal tubular cells such as OATPs, organic cation transporters (OCTs), multidrug and toxin extrusion proteins (MATEs), and P-glycoprotein (P-gp). Uptake of the typical substrates metformin for OCTs and MATEs and bromosulphophthalein (BSP) and atorvastatin for OATPs was measured in the absence and presence of a commercially available green tea and EGCG. Transcellular transport of digoxin, a typical substrate of P-gp, was measured over 4 hours in the absence and presence of green tea or EGCG in Caco-2 cell monolayers. OCT1-, OCT2-, MATE1- and MATE2-K-mediated metformin uptake was significantly reduced in the presence of green tea and EGCG (P < 0.05). BSP net uptake by OATP1B1 and OATP1B3 was inhibited by green tea [IC50 2.6% (v/v) and 0.39% (v/v), respectively]. Green tea also inhibited OATP1B1- and OATP1B3-mediated atorvastatin net uptake with IC50 values of 1.9% (v/v) and 1.0% (v/v), respectively. Basolateral to apical transport of digoxin was significantly decreased in the presence of green tea and EGCG. These findings indicate that green tea and EGCG inhibit multiple drug transporters in vitro. Further studies are necessary to investigate the effects of green tea on prototoypical substrates of these transporters in humans, in particular on substrates of hepatic uptake transporters (e.g. statins) as well as on P-glycoprotein substrates.

  19. The role of human cytochrome P450 enzymes in the formation of 2-hydroxymetronidazole: CYP2A6 is the high affinity (low Km) catalyst.

    PubMed

    Pearce, Robin E; Cohen-Wolkowiez, Michael; Sampson, Mario R; Kearns, Gregory L

    2013-09-01

    Despite metronidazole's widespread clinical use since the 1960s, the specific enzymes involved in its biotransformation have not been previously identified. Hence, in vitro studies were conducted to identify and characterize the cytochrome P450 enzymes involved in the formation of the major metabolite, 2-hydroxymetronidazole. Formation of 2-hydroxymetronidazole in human liver microsomes was consistent with biphasic, Michaelis-Menten kinetics. Although several cDNA-expressed P450 enzymes catalyzed 2-hydroxymetronidazole formation at a supratherapeutic concentration of metronidazole (2000 μM), at a "therapeutic concentration" of 100 μM only CYPs 2A6, 3A4, 3A5, and 3A7 catalyzed metronidazole 2-hydroxylation at rates substantially greater than control vector, and CYP2A6 catalyzed 2-hydroxymetronidazole formation at rates 6-fold higher than the next most active enzyme. Kinetic studies with these recombinant enzymes revealed that CYP2A6 has a Km = 289 μM which is comparable to the Km for the high-affinity (low-Km) enzyme in human liver microsomes, whereas the Km values for the CYP3A enzymes corresponded with the low-affinity (high-Km) component. The sample-to-sample variation in 2-hydroxymetronidazole formation correlated significantly with CYP2A6 activity (r ≥ 0.970, P < 0.001) at substrate concentrations of 100 and 300 μM. Selective chemical inhibitors of CYP2A6 inhibited metronidazole 2-hydroxylation in a concentration-dependent manner and inhibitory antibodies against CYP2A6 virtually eliminated metronidazole 2-hydroxylation (>99%). Chemical and antibody inhibitors of other P450 enzymes had little or no effect on metronidazole 2-hydroxylation. These results suggest that CYP2A6 is the primary catalyst responsible for the 2-hydroxylation of metronidazole, a reaction that may function as a marker of CYP2A6 activity both in vitro and in vivo.

  20. INHIBITION OF HUMAN AND RAT CYP1A2 BY TCDD AND DIOXIN-LIKE CHEMICALS

    EPA Science Inventory

    Dioxins have been shown to bind and induce rodent CYP1A2, producing a dose-dependent hepatic sequestration in vivo. The induction of CYP1A2 activity has been used as a noninvasive biomarker for human exposure to dioxins; while there is a consistent relationship between exposure ...

  1. 29 CFR 1917.28 - Hazard communication (See also § 1917.1(a)(2)(vi)).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Hazard communication (See also § 1917.1(a)(2)(vi)). 1917.28 Section 1917.28 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... communication (See also § 1917.1(a)(2)(vi))....

  2. Caffeine induces CYP1A2 expression in rat hepatocytes but not in human hepatocytes.

    PubMed

    Vaynshteyn, David; Jeong, Hyunyoung

    2012-06-01

    Caffeine is the active constituent in coffee. Continual consumption of caffeine can lead to an attenuated response also known as tolerance. Results from rat studies have shown that caffeine is an inducer of CYP1A2, the enzyme responsible for caffeine's metabolism. This suggests that CYP1A2 induction by caffeine may be in part responsible for caffeine tolerance. However, whether caffeine induces CYP1A2 expression in humans remains unknown. Our results from luciferase assays performed in HepG2 cells showed that caffeine is not an activator of the aromatic hydrocarbon receptor (AhR), a major transcription factor involved in upregulation of CYP1A2. Furthermore, caffeine did not induce CYP1A2 expression in primary human hepatocytes at a concentration attained by ordinary coffee drinking. On the other hand, caffeine enhanced CYP1A2 expression by 9-fold in rat hepatocytes. Our results suggest that caffeine from ordinary coffee drinking does not induce CYP1A2 expression in humans and that factors other than CYP1A2 induction by caffeine likely contribute to development of caffeine tolerance in humans.

  3. Measurement of CYP1A2 activity: a focus on caffeine as a probe.

    PubMed

    Perera, Vidya; Gross, Annette S; McLachlan, Andrew J

    2012-06-01

    The drug metabolising enzyme CYP1A2 contributes to the metabolism of a number of medicines including clozapine, olanzapine and theophylline. These medicines display a high degree of inter-individual variability in pharmacokinetics and response. Measuring CYP1A2 activity in vivo can be an important tool to identify the factors that influence variability in drug pharmacokinetics and inform dose selection. Caffeine is the only currently accepted probe to conduct in vivo phenotyping of CYP1A2. Despite the number of proposed matrices (biological fluid containing the drug and/or metabolite/s of interest) and metrics (mathematical formula relating the drug and/or metabolite/s to enzyme activity) proposed to measure CYP1A2 activity using caffeine, many of these are compromised by factors related to the specific metabolic pathway studied or pharmacokinetic characteristics of caffeine and its metabolites. Furthermore, questions regarding the appropriate study design and methodology to conduct studies to evaluate CYP1A2 activity have often been overlooked. These issues include the potential influence of a methylxanthine abstinence period prior to caffeine CYP1A2 phenotyping and the impact of caffeine formulation on determining CYP1A2 activity. This review aims to discuss the various CYP1A2 matrices and metrics with a particular focus on unresolved methodological issues.

  4. Tanshinone I increases CYP1A2 protein expression and enzyme activity in primary rat hepatocytes.

    PubMed

    Lee, Wayne Y W; Zhou, Xuelin; Or, Penelope M Y; Kwan, Yiu Wa; Yeung, John H K

    2012-01-15

    This study investigated the effects of Danshen and its active ingredients on the protein expression and enzymatic activity of CYP1A2 in primary rat hepatocytes. The ethanolic extract of Danshen roots (containing mainly tanshinones) inhibited CYP1A2-catalyzed phenacetin O-deethylation (IC(50)=24.6 μg/ml) in primary rat hepatocytes while the water extract containing mainly salvianolic acid B and danshenshu had no effect. Individual tanshinones such as cryptotanshinone, dihydrotanshinone, tanshinone IIA inhibited the CYP1A2-mediated metabolism with IC(50) values at 12.9, 17.4 and 31.9 μM, respectively. After 4-day treatment of the rat hepatocytes, the ethanolic extract of Danshen and tanshinone I increased rat CYP1A2 activity by 6.8- and 5.2-fold, respectively, with a concomitant up-regulation of CYP1A2 protein level by 13.5- and 6.5-fold, respectively. CYP1A2 induction correlated with the up-regulation of mRNA level of aryl hydrocarbon receptor (AhR), which suggested a positive feedback mechanism of tanshinone I-mediated CYP1A2 induction. A formulated Danshen pill (containing mainly danshensu and salvianolic acid B and the tanshinones) up-regulated CYP1A2 protein expression and enzyme activity, but danshensu and salvianolic acid B, when used individually, did not affect CYP1A2 activity. This study was the first report on the Janus action of the tanshinones on rat CYP1A2 activity.

  5. Cloning and functional characterization of the pig (Sus scrofa) organic anion transporting polypeptide 1a2.

    PubMed

    Yu, Yejin; Liu, Xiaoxiao; Zhang, Zheren; Xiao, Yunpeng; Hong, Mei

    2013-08-01

    1. Organic anion transporting polypeptides (OATPs) are a family of transporter proteins that have been extensively recognized as key determinants of absorption, distribution, metabolism and excretion of various drugs. Human OATP1A2 has been demonstrated to transport wide spectrum of endogenous and exogenous compounds. Study on OATP1A2 orthologues of other species, however, is still limited. 2. Here, we described the cloning and functional characterization of a member of the OATP/Oatp family member obtained from pig (Sus scrofa) liver. Sequence analysis suggested that it has a high homology with human OATP1A2 and bovine Oatp1a2. Prototypic substrates estrone-3-sulfate (E-3-S) and taurocholic acid were transported by the protein. The transport of these two substrates is pH-dependent, with lower pH showing higher uptake function. Kinetic study showed the transport of these two substrates have a Km of 42.5 ± 12.1 and 33.1 ± 8.7 µM, respectively. Pig Slco1a2 has the highest expression level in the liver, and to a less extend in the brain and small intestine. 3. In conclusion, an OATP member was cloned from pig liver. Sequence analysis and phylogenic study revealed it as an orthologue of human OATP1A2. Its kinetic characteristic for prototypic substrates and organ distribution are similar with that of OATP1A2.

  6. Differential effects of nicotine treatment and ethanol self-administration on CYP2A6, CYP2B6 and nicotine pharmacokinetics in African green monkeys.

    PubMed

    Ferguson, C S; Miksys, S; Palmour, R M; Tyndale, R F

    2012-12-01

    In primates, nicotine is metabolically inactivated in the liver by CYP2A6 and possibly CYP2B6. Changes in the levels of these two enzymes may affect nicotine pharmacokinetics and influence smoking behaviors. This study investigated the independent and combined effects of ethanol self-administration and nicotine treatment (0.5 mg/kg b.i.d. s.c.) on hepatic CYP2A6 and CYP2B6 levels (mRNA, protein, and enzymatic activity), in vitro nicotine metabolism, and in vivo nicotine pharmacokinetics in monkeys. CYP2A6 mRNA and protein levels and in vitro coumarin (selective CYP2A6 substrate) and nicotine metabolism were decreased by nicotine treatment but unaffected by ethanol. CYP2B6 protein levels and in vitro bupropion (selective CYP2B6 substrate) metabolism were increased by ethanol but unaffected by nicotine treatment; CYP2B6 mRNA levels were unaltered by either treatment. Combined ethanol and nicotine exposure decreased CYP2A6 mRNA and protein levels, as well as in vitro coumarin and nicotine metabolism, and increased CYP2B6 protein levels and in vitro bupropion metabolism, with no change in CYP2B6 mRNA levels. Chronic nicotine resulted in higher nicotine plasma levels achieved after nicotine administration, consistent with decreased CYP2A6. Ethanol alone, or combined with nicotine, resulted in lower nicotine plasma levels by a mechanism independent of the change in these enzymes. Thus, nicotine can decrease hepatic CYP2A6, reducing the metabolism of its substrates, including nicotine, whereas ethanol can increase hepatic CYP2B6, increasing the metabolism of CYP2B6 substrates. In vivo nicotine pharmacokinetics are differentially affected by ethanol and nicotine, but when both drugs are used in combination the effect more closely resembles ethanol alone.

  7. CYP2A6 and CYP2B6 genetic variation and its association with nicotine metabolism in South Western Alaska Native people

    PubMed Central

    Binnington, Matthew J.; Zhu, Andy Z.X.; Renner, Caroline C.; Lanier, Anne P.; Hatsukami, Dorothy K.; Benowitz, Neal L; Tyndale, Rachel F.

    2012-01-01

    Objectives Alaska Native people (AN) have a high prevalence of tobacco use and associated morbidity and mortality when compared to the general U.S. population. Variation in the CYP2A6 and CYP2B6 genes, encoding enzymes responsible for nicotine metabolic inactivation and procarcinogen activation, has not been characterized in AN and may contribute to the increased risk. Methods AN people (n = 400) residing in the Bristol Bay region of South Western Alaska were recruited for a cross-sectional study on tobacco use. They were genotyped for CYP2A6*1X2A, *1X2B, *1B, *2, *4, *7, *8, *9, *10, *12, *17, *35 and CYP2B6*4, *6, *9 and provided plasma and urine samples for measurement of nicotine and metabolites. Results CYP2A6 and CYP2B6 variant frequencies among the AN Yupik people (n=361) were significantly different from other ethnicities. Nicotine metabolism (as measured by the plasma and urinary ratio of metabolites trans-3’hydroxycotinine to cotinine [(3HC/COT)] was significantly associated with CYP2A6 (P< 0.001) but not CYP2B6 genotype (P = 0.95) when controlling for known covariates. Of note, plasma 3HC/COT ratios were high in the entire Yupik people, and among the Yupik CYP2A6 wild-type participants they were substantially higher than previously characterized racial/ethnic groups (P < 0.001 vs. Caucasians and African Americans). Conclusions Yupik AN people have a unique CYP2A6 genetic profile which associated strongly with in vivo nicotine metabolism. More rapid CYP2A6-mediated nicotine and nitrosamine metabolism in the Yupik people may modulate tobacco-related disease risk. PMID:22569203

  8. Cytochrome P450 1A2 Metabolizes 17β-Estradiol to Suppress Hepatocellular Carcinoma

    PubMed Central

    Ren, Jianwai; Chen, George G.; Liu, Yi; Su, Xianwei; Hu, Baoguang; Leung, Billy C. S.; Wang, Y.; Ho, Rocky L. K.; Yang, Shengli; Lu, Gang; Lee, C. G.; Lai, Paul B. S.

    2016-01-01

    Hepatocellular carcinoma (HCC) occurs more frequently in men than in women. It is commonly agreed that estrogen plays important roles in suppressing HCC development, however, the underlying mechanism remains largely unknown. Since estrogen is mainly metabolized in liver and its metabolites affect cell proliferation, we sought to investigate if the liver-specific cytochrome P450 1A2 (CYP1A2) mediated the inhibitory effect of estrogen on HCC. In this study, the expression of estrogen-metabolizing enzyme CYP1A2 was determined in HCC tissues and cell lines. Cell proliferation and apoptosis were assessed in cells with or without CYP1A2 overexpression. The levels of 17β-estradiol (E2) and its metabolite 2-methoxyestradiol (2-ME) were determined. A xenograft tumor model in mice was established to confirm the findings. It was found that CYP1A2 expression was greatly repressed in HCC. E2 suppressed HCC cell proliferation and xenograft tumor development by inducing apoptosis. The inhibitory effect was significantly enhanced in cells with CYP1A2 overexpression, which effectively conversed E2 to the cytotoxic 2-ME. E2 in combination with sorafenib showed an additive effect on HCC. The anti-HCC effect of E2 was not associated with estrogen receptors ERα and ERβ as well as tumor suppressor P53 but enhanced by the approved anti-HCC drug sorafenib. In addition, HDAC inhibitors greatly induced CYP1A2 promoter activities in cancer cells, especially liver cancer cells, but not in non-tumorigenic cells. Collectively, CYP1A2 metabolizes E2 to generate the potent anti-tumor agent 2-ME in HCC. The reduction of CYP1A2 significantly disrupts this metabolic pathway, contributing the progression and growth of HCC and the gender disparity of this malignancy. PMID:27093553

  9. Curcumin Successfully Inhibited the Computationally Identified CYP2A6 Enzyme-Mediated Bioactivation of Aflatoxin B1 in Arbor Acres broiler

    PubMed Central

    Muhammad, Ishfaq; Sun, Xiaoqi; Wang, He; Li, Wei; Wang, Xinghe; Cheng, Ping; Li, Sihong; Zhang, Xiuying; Hamid, Sattar

    2017-01-01

    Cytochrome P450 enzymes are often responsible for the toxic and carcinogenic effects of toxicants, such as aflatoxin B1 (AFB1). The human hepatic CYP2A6 enzyme mediates the oxidative metabolism of several procarcinogens. In this study, we characterized a partial sequence of CYP2A6 gene from Arbor Acres (AA) broiler and studied its role in AFB1 bioactivation. Moreover, the effect of curcumin on CYP2A6 is illustrated. Six groups of AA broiler were treated for 28 days including the control group (fed only basal diet), curcumin alone-treated group (450 mg/kg feed), the group fed AFB1-contaminated feed (5 mg/kg feed) plus the low (150 mg), medium (300 mg) or high (450 mg) of curcumin, and the group fed AFB1-contaminated diet alone (5 mg/kg feed). After the end of treatment period, liver samples were collected for different analyses. The results revealed that the histopathological examination showed clear signs of liver toxicity in AA broliers in AFB1-fed group, but curcumin-supplementation in feed prevented partially AFB1-induced liver toxicity. Liver and body weights were recorded to study the AFB1 harmful effects. We noted an obvious increase in liver weight and decrease in body weight in AFB1-fed group. But, the administration of curcumin partially ameliorated the increase in liver weight and decrease in body weight in a dose-dependent manner. The results (RT-PCR and Elisa) revealed that mRNA and protein expression level enhanced in AFB1-fed group. Consistently, CYP2A6 enzyme activity also increased in AFB1-fed group, suggesting that AA broiler CYP2A6 actively involved in bioactivation of AFB1. However, curcumin treatment inhibited CYP2A6 at mRNA and protein levels in AFB1 treated AA broiler in a dose-dependent manner. Maximum inhibition of liver CYP2A6 enzyme activity in AA broiler has been achieved at a dose of 450 mg/kg curcumin. This is the first study identifying and confirming the role of CYP2A6 enzyme in AFB1 bioactivation in AA broiler liver (in vivo), and

  10. Curcumin Successfully Inhibited the Computationally Identified CYP2A6 Enzyme-Mediated Bioactivation of Aflatoxin B1 in Arbor Acres broiler.

    PubMed

    Muhammad, Ishfaq; Sun, Xiaoqi; Wang, He; Li, Wei; Wang, Xinghe; Cheng, Ping; Li, Sihong; Zhang, Xiuying; Hamid, Sattar

    2017-01-01

    Cytochrome P450 enzymes are often responsible for the toxic and carcinogenic effects of toxicants, such as aflatoxin B1 (AFB1). The human hepatic CYP2A6 enzyme mediates the oxidative metabolism of several procarcinogens. In this study, we characterized a partial sequence of CYP2A6 gene from Arbor Acres (AA) broiler and studied its role in AFB1 bioactivation. Moreover, the effect of curcumin on CYP2A6 is illustrated. Six groups of AA broiler were treated for 28 days including the control group (fed only basal diet), curcumin alone-treated group (450 mg/kg feed), the group fed AFB1-contaminated feed (5 mg/kg feed) plus the low (150 mg), medium (300 mg) or high (450 mg) of curcumin, and the group fed AFB1-contaminated diet alone (5 mg/kg feed). After the end of treatment period, liver samples were collected for different analyses. The results revealed that the histopathological examination showed clear signs of liver toxicity in AA broliers in AFB1-fed group, but curcumin-supplementation in feed prevented partially AFB1-induced liver toxicity. Liver and body weights were recorded to study the AFB1 harmful effects. We noted an obvious increase in liver weight and decrease in body weight in AFB1-fed group. But, the administration of curcumin partially ameliorated the increase in liver weight and decrease in body weight in a dose-dependent manner. The results (RT-PCR and Elisa) revealed that mRNA and protein expression level enhanced in AFB1-fed group. Consistently, CYP2A6 enzyme activity also increased in AFB1-fed group, suggesting that AA broiler CYP2A6 actively involved in bioactivation of AFB1. However, curcumin treatment inhibited CYP2A6 at mRNA and protein levels in AFB1 treated AA broiler in a dose-dependent manner. Maximum inhibition of liver CYP2A6 enzyme activity in AA broiler has been achieved at a dose of 450 mg/kg curcumin. This is the first study identifying and confirming the role of CYP2A6 enzyme in AFB1 bioactivation in AA broiler liver (in vivo), and

  11. More potent inhibition of human CYP2A6 than mouse CYP2A5 enzyme activities by derivatives of phenylethylamine and benzaldehyde.

    PubMed

    Rahnasto, M; Raunio, H; Poso, A; Juvonen, R O

    2003-05-01

    1. A rapid 96-well plate assay method was developed and validated to measure liver microsomal coumarin 7-hydroxylation in vitro. 2. The method was used to test inhibition of human and mouse CYP2A enzymes by three phenylethylamine derivatives 2-(p-tolyl)-ethylamine, amphetamine, 2-phenylethylamine and benzaldehyde, and two of its derivatives, 4-methylbenzaldehyde and 4-methoxybenzaldehyde. 3. The benzaldehyde derivatives were more potent inhibitors of CYP2A5 than the phenylethylamines. The K(ic) value of 4-methylbenzaldehyde was 3.4 micro M and for 4-methoxybenzaldehyde it was 0.86 micro M for CYP2A5. 4. Amphetamine is a weak inhibitor of CYP2A6, whereas benzaldehyde is a suicide inhibitor with K(inact) = 0.16 min(-1) and K(I) = 18 micro M. The K(ic) values of 2-phenylethylamine, 2-(p-tolyl)-ethylamine, 4-methylbenzaldehyde and 4-methoxybenzaldehyde were 1.13, 0.23, 0.36 and 0.73 micro M for CYP2A6, respectively. 5. Novel potent inhibitors were found for CYP2A6 and, except for 4-methoxybenzaldehyde, all the compounds inhibited CYP2A5 and CYP2A6 enzymes differentially. These data add to the refinement of CYP2A enzyme active sites and provide chemical leads for developing novel chemical inhibitors of the CYP2A6 enzyme.

  12. Chloroquine and Hydroxychloroquine Are Novel Inhibitors of Human Organic Anion Transporting Polypeptide 1A2.

    PubMed

    Xu, Chenghao; Zhu, Ling; Chan, Ting; Lu, Xiaoxi; Shen, Weiyong; Madigan, Michele C; Gillies, Mark C; Zhou, Fanfan

    2016-02-01

    Chloroquine (CQ) and hydroxychloroquine (HCQ) are widely used to treat malaria and inflammatory diseases, long-term usage of which often causes severe side effects, especially retinopathy. Solute carrier transporters (SLCs) are important proteins responsible for the cellular uptake of endogenous and exogenous substances. Inhibitors competing with transporter substrates for SLCs often results in unfavorable toxicities and unsatisfactory therapeutic outcomes. We investigated the inhibitory effect of CQ and HCQ on substrate uptake mediated through a range of important SLC transporters in overexpressing human embryonic kidney (HEK293) cells. Our data revealed that both CQ and HCQ potently inhibit the uptake activity of organic anion transporting polypeptide 1A2 (OATP1A2). We recently reported OATP1A2 to be expressed in human retinal pigment epithelium (RPE), where it mediates cellular uptake of all-trans-retinol (atROL), a key step in the classical visual cycle. In this study, we demonstrate that CQ and HCQ could markedly impair atROL uptake in OATP1A2-expressing HEK293 cells and more importantly, in primary human RPE cells. Our study shows that CQ and HCQ are novel inhibitors of OATP1A2 and significantly impair OATP1A2-mediated substrate uptake, particularly transport of atROL into the RPE. This effect may compromise the function of the classic visual cycle leading to vision impairment and contribute to the retinopathy observed clinically in patients using CQ or HCQ.

  13. Identification of N-(hydroxymethyl) norcotinine as a major product of cytochrome P450 2A6, but not cytochrome P450 2A13-catalyzed cotinine metabolism.

    PubMed

    Brown, Kathryn M; von Weymarn, Linda B; Murphy, Sharon E

    2005-12-01

    Cotinine formation is the major pathway of nicotine metabolism in smokers, and the primary pathway of cotinine metabolism is trans-3'-hydroxylation. trans-3'-Hydroxycotinine and its glucuronide conjugate account for up to 50% of the nicotine metabolites excreted by smokers. Minor metabolites of cotinine excreted by smokers include norcotinine and cotinine N-oxide, each of which account for <5% of the nicotine dose. It has been reported that P450 2A6 is the catalyst of cotinine metabolism. However, we report here that the major product of P450 2A6-catalyzed cotinine metabolism is N-(hydroxymethyl)norcotinine, a previously unknown human metabolite of cotinine. N-(Hydroxymethyl)norcotinine was chemically synthesized, and its stability under the conditions of the enzyme reactions was confirmed. The products of P450 2A6-catalyzed [5-3H]cotinine metabolism were quantified by radioflow HPLC. The identification of N-(hydroxymethyl)norcotinine as the major metabolite was based on HPLC analysis on three unique systems and coelution with N-(hydroxymethyl)norcotinine standard. 5'-Hydroxycotinine and trans-3'-hydroxycotinine were minor products of P450 2A6-catalyzed cotinine metabolism, accounting for 14 and 8% of the total cotinine metabolites, respectively. N-(Hydroxymethyl)norcotinine was a product of cotinine metabolism by the extrahepatic P450, 2A13, but it was a minor one. The major product of P450 2A13-catalyzed cotinine metabolism was 5'-hydroxycotinine, which was formed at twice the rate of trans-3'-hydroxycotinine. The identification of all cotinine metabolites formed by both enzymes was confirmed by LC/MS/MS analysis. Kinetic parameters for cotinine metabolism were determined for P450 2A6 and P450 2A13. This work has confirmed that the major metabolite of cotinine in smokers, trans-3'-hydroxycotinine, is only a minor metabolite of P450 2A6-catalyzed cotinine metabolism.

  14. Suppression of Lipid Accumulation by Indole-3-Carbinol Is Associated with Increased Expression of the Aryl Hydrocarbon Receptor and CYP1B1 Proteins in Adipocytes and with Decreased Adipocyte-Stimulated Endothelial Tube Formation

    PubMed Central

    Wang, Mei-Lin; Lin, Shyh-Hsiang; Hou, Yuan-Yu; Chen, Yue-Hwa

    2016-01-01

    This study investigated the effects of indole-3-carbinol (I3C) on adipogenesis- and angiogenesis-associated factors in mature adipocytes. The cross-talk between mature adipocytes and endothelial cells (ECs) was also explored by cultivating ECs in a conditioned medium (CM) by using I3C-treated adipocytes. The results revealed that I3C significantly inhibited triglyceride accumulation in mature adipocytes in association with significantly increased expression of AhR and CYP1B1 proteins as well as slightly decreased nuclear factor erythroid-derived factor 2–related factor 2, hormone-sensitive lipase, and glycerol-3-phosphate dehydrogenase expression by mature adipocytes. Furthermore, I3C inhibited CM-stimulated endothelial tube formation, which was accompanied by the modulated secretion of angiogenic factors in adipocytes, including vascular endothelial growth factor, interleukin-6, matrix metalloproteinases, and nitric oxide. In conclusion, I3C reduced lipid droplet accumulation in adipocytes and suppressed adipocyte-stimulated angiogenesis in ECs, suggesting that I3C is a potential therapeutic agent for treating obesity and obesity-associated disorders. PMID:27527145

  15. High Resolution Spectroscopy of A^1B1u ← X^1A_g 8^1_04^1_0 Band of Naphthalene Referenced to AN Optical Frequency Comb

    NASA Astrophysics Data System (ADS)

    Nakashima, Kazuki; Nishiyama, Akiko; Misono, Masatoshi

    2016-06-01

    In the excited vibronic states of naphthalene, there exist various interesting interactions such as intramolecular vibrational energy redistribution (IVR), intersystem crossing (ISC), and internal conversion (IC). More than thirty yeas ago, Beck et al. showed that IVR became remarkable when the excess energy exceeded about 2000 cm-1^, ^a. In the present study, we observe Doppler-free two-photon absorption spectra of A^1B1u ← X^1A_g 8^1_04^1_0 band of naphthalene around 34281 cm-1. The excess energy is 2261 cm-1, which is just above the threshold of IVR. Thus we expect this band is suitable to analyze the dynamics in the excited vibronic states. In our experiment, the spectral resolution is about 100 kHz, and rovibronic lines are well-resolved. To decide the transition frequencies, frequency shifts, and spectral linewidths with high accuracy and precision, we employed the comb-referenced Doppler-free two-photon absorption spectroscopic system^b. We proceed to assign the rovibronic lines in ^qQ transition, and to determine molecular constants in the excited vibronic state. ^a S. M. Beck, J. B. Hopkins, D. E. Powers, and R. E. Smalley, J. Chem. Phys. 74, 43(1981). ^b A. Nishiyama, K. Nakashima, A. Matsuba, and M. Misono, J. Mol. Spectrosc. 318, 40 (2015).

  16. Inhibition effects of Vernonia cinerea active compounds against cytochrome P450 2A6 and human monoamine oxidases, possible targets for reduction of tobacco dependence.

    PubMed

    Prasopthum, Aruna; Pouyfung, Phisit; Sarapusit, Songklod; Srisook, Ekaruth; Rongnoparut, Pornpimol

    2015-04-01

    The human cytochrome P450 2A6 (CYP2A6) and monoamine oxidases (MAO-A and MAO-B), catalyzing nicotine and dopamine metabolisms, respectively, are two therapeutic targets of nicotine dependence. Vernonia cinerea, a medicinal plant commonly used for treatment of diseases such as asthma and bronchitis, has been shown reducing tobacco dependence effect among tobacco users. In the present study, we found eight active compounds isolated from V. cinerea that comprise inhibitory activity toward CYP2A6 and MAO-A and MAO-B enzymes using activity-guided assays, with coumarin as substrate of CYP2A6 and kynuramine of MAOs. These compounds were three flavones (apigenin, chrysoeriol, luteolin), one flavonol (quercetin), and four hirsutinolide-type sesquiterpene lactones (8α-(2-methylacryloyloxy)-hirsutinolide-13-O-acetate, 8α-(4-hydroxymethacryloyloxy)-hirsutinolide-13-O-acetate, 8α-tigloyloxyhirsutinolide-13-O-acetate, and 8α-(4-hydroxytigloyloxy)-hirsutinolide-13-O-acetate). Modes and kinetics of inhibition against the three enzymes were determined. Flavonoids possessed strong inhibitory effect on CYP2A6 in reversible mode, while inhibition by hirsutinolides was mechanism-based (NADPH-, concentration-, and time-dependence) and irreversible. Inhibition by hirsutinolides could not be reversed by dialysis and by addition of trapping agents or potassium ferricyanide. Flavonoids inhibited MAOs with variable degrees and were more prominent in inhibition toward MAO-A than hirsutinolides, while two of hirsutinolides inhibited MAO-B approximately comparable to two flavonoids. These results could have implications in combination of drug therapy for smoking cessation.

  17. The Role of Protein Elongation Factor eEF1A2 in Breast Cancer

    DTIC Science & Technology

    2006-09-01

    31, 301-5. Page 11 Appendix A. Figures. Page 12 negative or weak moderate or strong years from diagnosis p= 0.005 cu m m u la ti ve s u rv iv al3...function of years following diagnosis . The difference is significant at p = 0.005. b 0 1 2 3 4 5 6 7 8 9 eEF1A2 negative eEF1A2 positive T u m o u r si ze...mouse model of aristolochic acid nephropathy , and human kidney-proximal tubule cells. Satisfyingly, one of these targets is Dishevelled 2 (DVL2

  18. Thermal ramp tritium release in COBRA-1A2 C03 beryllium pebbles

    SciTech Connect

    Baldwin, D.L.

    1998-03-01

    Tritium release kinetics, using the method of thermal ramp heating at three linear ramp rates, were measured on the COBRA-1A2 C03 1-mm beryllium pebbles. This report includes a brief discussion of the test, and the test data in graph format.

  19. COMPARING ENVIRONMENTALLY RELEVANT PCBS TO TCDD IN CYP1A2 NULL AND WILDTYPE MICE

    EPA Science Inventory


    The role of CYP1A2 on the interactions of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin, dioxin), dioxin-like (DL) and non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) was compared in multiple responses of different laboratory-defined mixtures, based on mass ratios found in...

  20. EVIDENCE FOR BROMODICHLOROMETHANE METABOLISM BY CYTOCHROME P-450 1A2

    EPA Science Inventory

    EVIDENCE FOR BROMODICHLOROMETHANE METABOLISM BY CYTOCHROME P-450 1A2. T M Ross1, B P Anderson1, G Zhao2, R A Pegram1 and J W Allis1. 1U.S. EPA, ORD, NHEERL, Research Triangle Park, NC; 2University of North Carolina, Chapel Hill, NC.
    Sponsor: H Barton

    Bromodichlorometh...

  1. 29 CFR 1917.28 - Hazard communication (See also § 1917.1(a)(2)(vi)).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Hazard communication (See also § 1917.1(a)(2)(vi)). 1917.28 Section 1917.28 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Marine Terminal Operations § 1917.28...

  2. 29 CFR 1917.28 - Hazard communication (See also § 1917.1(a)(2)(vi)).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Hazard communication (See also § 1917.1(a)(2)(vi)). 1917.28 Section 1917.28 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Marine Terminal Operations § 1917.28...

  3. 29 CFR 1917.28 - Hazard communication (See also § 1917.1(a)(2)(vi)).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Hazard communication (See also § 1917.1(a)(2)(vi)). 1917.28 Section 1917.28 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Marine Terminal Operations § 1917.28...

  4. Novel Natural Inhibitors of CYP1A2 Identified by in Silico and in Vitro Screening

    PubMed Central

    Zhu, Ruixin; Hu, Liwei; Li, Haiyun; Su, Juan; Cao, Zhiwei; Zhang, Weidong

    2011-01-01

    Inhibition of cytochrome P450 (CYP) is a major cause of herb–drug interactions. The CYP1A2 enzyme plays a major role in the metabolism of drugs in humans. Its broad substrate specificity, as well as its inhibition by a vast array of structurally diverse herbal active ingredients, has indicated the possibility of metabolic herb–drug interactions. Therefore nowadays searching inhibitors for CYP1A2 from herbal medicines are drawing much more attention by biological, chemical and pharmological scientists. In our work, a pharmacophore model as well as the docking technology is proposed to screen inhibitors from herbal ingredients data. Firstly different pharmaphore models were constructed and then validated and modified by 202 herbal ingredients. Secondly the best pharmaphore model was chosen to virtually screen the herbal data (a curated database of 989 herbal compounds). Then the hits (147 herbal compounds) were continued to be filtered by a docking process, and were tested in vitro successively. Finally, five of eighteen candidate compounds (272, 284, 300, 616 and 817) were found to have inhibition of CYP1A2 activity. The model developed in our study is efficient for in silico screening of large herbal databases in the identification of CYP1A2 inhibitors. It will play an important role to prevent the risk of herb–drug interactions at an early stage of the drug development process. PMID:21686183

  5. Familial Hemiplegic Migraine with Severe Attacks: A New Report with ATP1A2 Mutation

    PubMed Central

    Martínez, E.; Moreno, R.; López-Mesonero, L.; Vidriales, I.; Ruiz, M.; Tellería, J. J.

    2016-01-01

    Introduction. Familial hemiplegic migraine (FHM) is a rare disorder characterized by migraine attacks with motor weakness during the aura phase. Mutations in CACNA1A, ATP1A2, SCN1A, and PRRT2 genes have been described. Methods. To describe a mutation in ATP1A2 gene in a FHM case with especially severe and prolonged symptomatology. Results. 22-year-old woman was admitted due to migraine-type headache and sudden onset of right-sided weakness and aphasia; she had similar episodes in her childhood. Her mother was diagnosed with hemiplegic migraine without genetic confirmation. She presented with fever, decreased consciousness, left gaze preference, mixed aphasia, right facial palsy, right hemiplegia, and left crural paresis. Computed tomography (CT) showed no lesion and CT perfusion study evidenced oligohemia in left hemisphere. A normal brain magnetic resonance (MR) was obtained. Impaired consciousness and dysphasia began to improve three days after admission and mild dysphasia and right hemiparesis lasted for 10 days. No recurrences were reported during a follow-up of two years. We identified a variant in heterozygous state in ATP1A2 gene (p.Thr364Met), pathogenic according to different prediction algorithms (SIFT, PolyPhen2, MutationTaster, and Condel). Conclusion. Prolonged and severe attacks with diffuse hypoperfusion in a FHM seemed to be specially related to ATP1A2 mutations, and p.T364M should be considered. PMID:27818813

  6. Cytochrome P450 1A2 Detoxicates Aristolochic Acid in the Mouse

    PubMed Central

    Einolf, Heidi J.; Dickman, Kathleen G.; Wang, Lai; Smith, Amanda; Grollman, Arthur P.

    2010-01-01

    Aristolochic acids (AAs) are plant-derived nephrotoxins and carcinogens responsible for chronic renal failure and associated urothelial cell cancers in several clinical syndromes known collectively as aristolochic acid nephropathy (AAN). Mice provide a useful model for study of AAN because the renal histopathology of AA-treated mice is strikingly similar to that of humans. AA is also a potent carcinogen in mice with a tissue spectrum somewhat different from that in humans. The toxic dose of AA in mice is higher than that in humans; this difference in susceptibility has been postulated to reflect differing rates of detoxication between the species. Recent studies in mice have shown that the hepatic cytochrome P450 system detoxicates AA, and inducers of the arylhydrocarbon response protect mice from the nephrotoxic effects of AA. The purpose of this study was to determine the role of specific cytochrome P450 (P450) enzymes in AA metabolism in vivo. Of 18 human P450 enzymes we surveyed only two, CYP1A1 and CYP1A2, which were effective in demethylating 8-methoxy-6-nitro-phenanthro-(3,4-d)-1,3-dioxolo-5-carboxylic acid (AAI) to the nontoxic derivative 8-hydroxy-6-nitro-phenanthro-(3,4-d)-1,3-dioxolo-5-carboxylic acid (AAIa). Kinetic analysis revealed similar efficiencies of formation of AAIa by human and rat CYP1A2. We also report here that CYP1A2-deficient mice display increased sensitivity to the nephrotoxic effects of AAI. Furthermore, Cyp1a2 knockout mice accumulate AAI-derived DNA adducts in the kidney at a higher rate than control mice. Differences in bioavailability or hepatic metabolism of AAI, expression of CYP1A2, or efficiency of a competing nitroreduction pathway in vivo may explain the apparent differences between human and rodent sensitivity to AAI. PMID:20164109

  7. Structural and Biophysical Characterization of Human Cytochromes P450 2B6 and 2A6 Bound to Volatile Hydrocarbons: Analysis and Comparison

    PubMed Central

    Wilderman, P. Ross; Liu, Jingbao; Jang, Hyun-Hee; Zhang, Qinghai; Stout, C. David; Halpert, James R.

    2015-01-01

    X-ray crystal structures of complexes of cytochromes CYP2B6 and CYP2A6 with the monoterpene sabinene revealed two distinct binding modes in the active sites. In CYP2B6, sabinene positioned itself with the putative oxidation site located closer to the heme iron. In contrast, sabinene was found in an alternate conformation in the more compact CYP2A6, where the larger hydrophobic side chains resulted in a significantly reduced active-site cavity. Furthermore, results from isothermal titration calorimetry indicated a much more substantial contribution of favorable enthalpy to sabinene binding to CYP2B6 as opposed to CYP2A6, consistent with the previous observations with (+)-α-pinene. Structural analysis of CYP2B6 complexes with sabinene and the structurally similar (3)-carene and comparison with previously solved structures revealed how the movement of the F206 side chain influences the volume of the binding pocket. In addition, retrospective analysis of prior structures revealed that ligands containing –Cl and –NH functional groups adopted a distinct orientation in the CYP2B active site compared with other ligands. This binding mode may reflect the formation of Cl-π or NH-π bonds with aromatic rings in the active site, which serve as important contributors to protein-ligand binding affinity and specificity. Overall, the findings from multiple techniques illustrate how drugs metabolizing CYP2B6 and CYP2A6 handle a common hydrocarbon found in the environment. The study also provides insight into the role of specific functional groups of the ligand that may influence the binding to CYP2B6. PMID:25585967

  8. Influence of synthetic and natural food dyes on activities of CYP2A6, UGT1A6, and UGT2B7.

    PubMed

    Kuno, Nayumi; Mizutani, Takaharu

    2005-08-27

    Synthetic or natural food dyes are typical xenobiotics, as are drugs and pollutants. After ingestion, part of these dyes may be absorbed and metabolized by phase I and II drug-metabolizing enzymes and excreted by transporters of phase III enzymes. However, there is little information regarding the metabolism of these dyes. It was investigated whether these dyes are substrates for CYP2A6 and UDP-glucuronosyltransferase (UGT). The in vitro inhibition of drug-metabolizing enzymes by these dyes was also examined. The synthetic food dyes studied were amaranth (food red no. 2), erythrosine B (food red no. 3), allura red (food red no. 40), new coccine (food red no. 102), acid red (food red no. 106), tartrazine (food Yellow no. 4), sunset yellow FCF (food yellow no. 5), brilliant blue FCF (food blue no. 1), and indigo carmine (food blue no. 2). The natural additive dyes studied were extracts from purple sweet potato, purple corn, cochineal, monascus, grape skin, elderberry, red beet, gardenia, and curthamus. Data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. Only indigo carmine inhibited CYP2A6 in a noncompetitive manner, while erythrosine B inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). In the natural additive dyes just listed, only monascus inhibited UGT1A6 and UGT2B7.

  9. Electrochemical reduction of flavocytochromes 2B4 and 1A2 and their catalytic activity.

    PubMed

    Shumyantseva, V V; Bulko, T V; Bachmann, T T; Bilitewski, U; Schmid, R D; Archakov, A I

    2000-05-01

    The present study shows that cytochromes P450 2B4 and 1A2 with a covalently attached riboflavin (semisynthetic flavocytochromes RfP450 2B4 and RfP450 1A2) can be reduced electrochemically on rhodium-graphite electrodes at a potential of -500 mV (vs Ag/AgCl). In the presence of substrates such as aminopyrine, aniline, 7-ethoxyresorufin, and 7-pentoxyresorufin, N-demethylation, p-hydroxylation, and O-dealkylation reactions proceeded, as was confirmed by product analysis. Rates of electrocatalytically driven reactions are comparable to those obtained using NAD(P)H as the source of reducing equivalents. These results suggest the practicality of developing flavocytochrome P450s as catalysts for oxidation reactions with different classes of organic substrates.

  10. SLC1A2 variant associated with essential tremor but not Parkinson disease in Chinese subjects.

    PubMed

    Tan, Eng-King; Foo, Jia-Nee; Tan, Louis; Au, Wing-Lok; Prakash, Kumar M; Ng, Ebonne; Ikram, M Kamran; Wong, Tien-Yin; Liu, Jian-Jun; Zhao, Yi

    2013-04-23

    Essential tremor (ET) is characterized by postural and action tremor.(1-3) A genome-wide association study (GWAS) identified a LINGO1 gene variant to be associated with ET.(4) Subsequent GWAS further identified an intronic variant (rs3794087) of the main glial glutamate transporter (SLC1A2) gene to be associated with ET with an odds ratio (OR) of approximately 1.4.(5) We conducted a case-control study to examine the SLC1A2 gene variant in an Asian cohort of ET. In addition, we also investigated the variant in patients with Parkinson disease (PD) because th