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1.
Pharmacogenomics J ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959879

RESUMO

Nicotine is the major pharmacologically active substance in tobacco. Several studies have examined genotypes related to nicotine metabolism, but few studies have been performed in the Mexican population. The objective was to identify associations between gene variants in metabolizing enzymes and the urinary levels of nicotine metabolites among Mexican smokers. The levels of nicotine and its metabolites were determined in the urine of 88 young smokers from Mexico, and 167 variants in 24 genes associated with nicotine metabolism were genotyped by next-generation sequencing (NGS). Trans-3'-hydroxy-cotinine (3HC) and 4-hydroxy-4-(3-pyridyl)-butanoic acid were the most abundant metabolites (35 and 17%, respectively). CYP2A6*12 was associated with 3HC (p = 0.014). The rs145014075 was associated with creatinine-adjusted levels of nicotine (p = 0.035), while the rs12471326 (UGT1A9) was associated to cotinine-N-glucuronide (p = 0.030). CYP2A6 and UGT1A9 variants are associated to nicotine metabolism. 4HPBA metabolite was an abundant urinary metabolite in young Mexican smokers.

2.
Nat Commun ; 11(1): 27, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911640

RESUMO

Impaired lung function is often caused by cigarette smoking, making it challenging to disentangle its role in lung cancer susceptibility. Investigation of the shared genetic basis of these phenotypes in the UK Biobank and International Lung Cancer Consortium (29,266 cases, 56,450 controls) shows that lung cancer is genetically correlated with reduced forced expiratory volume in one second (FEV1: rg = 0.098, p = 2.3 × 10-8) and the ratio of FEV1 to forced vital capacity (FEV1/FVC: rg = 0.137, p = 2.0 × 10-12). Mendelian randomization analyses demonstrate that reduced FEV1 increases squamous cell carcinoma risk (odds ratio (OR) = 1.51, 95% confidence intervals: 1.21-1.88), while reduced FEV1/FVC increases the risk of adenocarcinoma (OR = 1.17, 1.01-1.35) and lung cancer in never smokers (OR = 1.56, 1.05-2.30). These findings support a causal role of pulmonary impairment in lung cancer etiology. Integrative analyses reveal that pulmonary function instruments, including 73 novel variants, influence lung tissue gene expression and implicate immune-related pathways in mediating the observed effects on lung carcinogenesis.

3.
Int J Cancer ; 146(7): 1862-1878, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31696517

RESUMO

We have recently completed the largest GWAS on lung cancer including 29,266 cases and 56,450 controls of European descent. The goal of our study has been to integrate the complete GWAS results with a large-scale expression quantitative trait loci (eQTL) mapping study in human lung tissues (n = 1,038) to identify candidate causal genes for lung cancer. We performed transcriptome-wide association study (TWAS) for lung cancer overall, by histology (adenocarcinoma, squamous cell carcinoma and small cell lung cancer) and smoking subgroups (never- and ever-smokers). We performed replication analysis using lung data from the Genotype-Tissue Expression (GTEx) project. DNA damage assays were performed in human lung fibroblasts for selected TWAS genes. As expected, the main TWAS signal for all histological subtypes and ever-smokers was on chromosome 15q25. The gene most strongly associated with lung cancer at this locus using the TWAS approach was IREB2 (pTWAS = 1.09E-99), where lower predicted expression increased lung cancer risk. A new lung adenocarcinoma susceptibility locus was revealed on 9p13.3 and associated with higher predicted expression of AQP3 (pTWAS = 3.72E-6). Among the 45 previously described lung cancer GWAS loci, we mapped candidate target gene for 17 of them. The association AQP3-adenocarcinoma on 9p13.3 was replicated using GTEx (pTWAS = 6.55E-5). Consistent with the effect of risk alleles on gene expression levels, IREB2 knockdown and AQP3 overproduction promote endogenous DNA damage. These findings indicate genes whose expression in lung tissue directly influences lung cancer risk.

4.
J Pharmacol Exp Ther ; 372(1): 21-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31628204

RESUMO

During tobacco and e-cigarette use, nicotine is mainly metabolized in the human liver by cytochrome P450 2A6 (CYP2A6). Given that a slower CYP2A6 metabolism has been associated with less vulnerability to develop nicotine dependence, the current studies sought to validate a novel CYP2A6 inhibitor, (5-(4-ethylpyridin-3-yl)thiophen-2-yl)methanamine (DLCI-1), for its effects on intravenous nicotine self-administration. Male and female mice were trained to self-administer nicotine across daily sessions. Once stable responding was achieved, DLCI-1 or vehicle control was administered prior to nicotine sessions. We found that the lower 25 mg/kg and moderate 50 mg/kg doses of DLCI-1 induced a significant decrease in nicotine intake for both males and females. DLCI-1 was further shown to be more effective than a moderate 1 mg/kg dose of bupropion on reducing nicotine intake and did not exert the adverse behavioral effects found with a high 75 mg/kg dose of bupropion. Although mice treated with DLCI-1 self-administered significantly less nicotine, similar nicotine-mediated behavioral effects on locomotion were observed. Together, along with the analysis of nicotine metabolites during self-administration, these findings support the contention that blocking hepatic nicotine metabolism would allow for similar activation of nicotinic acetylcholine receptors at lower nicotine doses. Moreover, these effects of DLCI-1 were specific to nicotine self-administration, as DLCI-1 did not result in any behavioral changes during food self-administration. Taken together, these studies validate DLCI-1 as a novel compound to decrease nicotine consumption, which may thereby promote tobacco and nicotine product cessation. SIGNIFICANCE STATEMENT: Current pharmacological approaches for nicotine and tobacco cessation have only been able to achieve limited efficaciousness in promoting long-term abstinence. In this work, we characterize the effects of a novel compound, (5-(4-ethylpyridin-3-yl)thiophen-2-yl)methanamine (DLCI-1), which inhibits the main enzyme that metabolizes nicotine, and we report a significant decrease in intravenous nicotine self-administration in male and female mice, supporting the potential of DLCI-1 as a novel tobacco cessation pharmacotherapeutic.

5.
Drug Metab Dispos ; 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31836608

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are potent carcinogens and are a primary risk factor in the development of lung and other aerodigestive tract cancers in smokers. The detoxification of PAHs by glucuronidation is well-characterized for the UDP-glycosyltransferase (UGT) 1A, 2A, and 2B subfamilies; however, the role of the UGT3A subfamily in PAH metabolism remains poorly understood. UGT3A enzymes are functionally distinct from other UGT subfamilies (which utilize UDP-glucuronic acid as cosubstrate) due to their utilization of alternative cosubstrates (UDP-N-acetylglucosamine for UGT3A1, and UDP-glucose and UDP-xylose for UGT3A2). The goal of the present study was to characterize UGT3A glycosylation activity against PAHs and examine their expression in human aerodigestive tract tissues. In vitro metabolism assays using UGT3A2-overexpressing cell microsomes indicated that UGT3A2 exhibits glycosylation activity against all of the simple and complex PAHs tested. The Vmax/Km ratios for UGT3A2 activity with UDP-xylose vs. UDP-glucose as cosubstrate ranged from 0.71-4.0 for all PAHs tested, demonstrating that PAH glycosylation may be occurring at rates up to four-fold higher with UDP-xylose than UDP-glucose. Limited glycosylation activity was observed against PAHs with UGT3A1-overexpressing cell microsomes. While UGT3A2 exhibited low levels of hepatic expression, it was shown by Western blot analysis to be widely expressed in aerodigestive tract tissues. Conversely, UGT3A1 exhibited highest expression in liver with lower expression in aerodigestive tract tissues. These data suggest that UGT3A2 plays an important role in the detoxification of PAHs in aerodigestive tract tissues, and that there may be cosubstrate dependent differences in the detoxification of PAHs by UGT3A2. SIGNIFICANCE STATEMENT: UGT3A2 is highly active against PAHs with either UDP-glucose or UDP-xylose as a cosubstrate. UGT3A1 exhibited low levels of activity against PAHs. UGT3A1 is highly expressed in liver while UGT3A2 is well-expressed in extra-hepatic tissues. UGT3A2 may be an important detoxifier of PAHs in humans.

6.
Am J Epidemiol ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31781743

RESUMO

Head and neck cancer (HNC) risk prediction models based on risk factor profiles have not yet been developed. We took advantage of the large database including 14 studies (1981-2010) in the US from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium to develop risk prediction models. Seventy percent of the data were used to develop HNC risk prediction models; the remaining 30% were used to validate the models. We used competing risk models to calculate absolute risks. The predictors included age, sex, education, race/ethnicity, alcohol drinking intensity, cigarette smoking duration and intensity or family history of HNC. The 20-year absolute HNC risk was 7.61% for a 60-year-old woman who smoked >20 cigarettes/day for >20 years, drank 3+ alcoholic drinks/day, was a high school graduate, with family history of HNC and was non-Hispanic White. The 20-year risk for men with a similar profile was 6.85%. The absolute risks of oropharyngeal and hypopharyngeal cancers were generally lower than those of oral cavity and laryngeal cancers. The AUC statistics were 0.70 or higher except for oropharyngeal cancer in men. The HNC risk prediction model may be useful in promoting healthier behaviors such as smoking cessation, or in aiding individuals with family history of HNC to evaluate their risks.

7.
J Diabetes Sci Technol ; : 1932296819883291, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640422

RESUMO

BACKGROUND: Recent reports have suggested that insulin vials purchased in community pharmacies do not meet the minimum required intact insulin concentration (≥95 U/mL) as defined by the United States Pharmacopeia. We sought to independently obtain multidose human insulin vials from a variety of community pharmacies across the state of Washington and quantitatively measure intact insulin. METHODS: Sixty 10-mL vials of insulin (n = 30 regular human insulin and n = 30 neutral protamine Hagedorn insulin) were purchased and assayed. To ensure random selection of lots and supply chain sources, insulin samples were purchased on a variety of calendar dates from various pharmacy locations across Washington State, inclusive of both chain and independent pharmacies. All samples were assessed for intact insulin concentration via both Ultra Performance Liquid Chromatography coupled with UV detection (UPLC-UV) and Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). RESULTS: When considering all samples (N = 60), the mean concentration was 101.8 ± 4.4and 91.5 ± 1.9 U/mL as determined by UPLC-UV and UPLC-MS, respectively. Measured concentrations ranged from 90.0 to 108.4 U/mL when assayed by UV UPLC and 86.1 to 95.4 U/mL for UPLC-MS. CONCLUSION: To our knowledge, this is the first study following the report by Carter et al that assessed human insulin concentrations by both UPLC-UV and UPLC-MS. These findings are important because they demonstrate that the results obtained from these two methods differ and that the method used must be considered when interpreting findings.

8.
Int J Cancer ; 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31577861

RESUMO

Genome-wide association studies (GWAS) have identified 45 susceptibility loci associated with lung cancer. Only less than SNPs, small insertions and deletions (INDELs) are the second most abundant genetic polymorphisms in the human genome. INDELs are highly associated with multiple human diseases, including lung cancer. However, limited studies with large-scale samples have been available to systematically evaluate the effects of INDELs on lung cancer risk. Here, we performed a large-scale meta-analysis to evaluate INDELs and their risk for lung cancer in 23,202 cases and 19,048 controls. Functional annotations were performed to further explore the potential function of lung cancer risk INDELs. Conditional analysis was used to clarify the relationship between INDELs and SNPs. Four new risk loci were identified in genome-wide INDEL analysis (1p13.2: rs5777156, Insertion, OR = 0.92, p = 9.10 × 10-8 ; 4q28.2: rs58404727, Deletion, OR = 1.19, p = 5.25 × 10-7 ; 12p13.31: rs71450133, Deletion, OR = 1.09, p = 8.83 × 10-7 ; and 14q22.3: rs34057993, Deletion, OR = 0.90, p = 7.64 × 10-8 ). The eQTL analysis and functional annotation suggested that INDELs might affect lung cancer susceptibility by regulating the expression of target genes. After conducting conditional analysis on potential causal SNPs, the INDELs in the new loci were still nominally significant. Our findings indicate that INDELs could be potentially functional genetic variants for lung cancer risk. Further functional experiments are needed to better understand INDEL mechanisms in carcinogenesis.

9.
Drug Metab Dispos ; 47(12): 1388-1396, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31578206

RESUMO

Menthol, which creates mint flavor and scent, is often added to tobacco in both menthol and nonmenthol cigarettes. A potent tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is extensively metabolized to its equally carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) as (R)- or (S)-NNAL enantiomers. NNAL is detoxified by UDP-glucuronosyltransferase (UGT) enzymes, with glucuronidation occurring on either NNAL's pyridine ring nitrogen (NNAL-N-Gluc) or the chiral alcohol [(R)- or (S)-NNAL-O-Gluc]. To characterize a potential effect by menthol on NNAL glucuronidation, in vitro menthol glucuronidation assays and menthol inhibition of NNAL-Gluc formation assays were performed. Additionally, NNAL and menthol glucuronides (MG) were measured in the urine of smokers (n = 100) from the Southern Community Cohort Study. UGTs 1A9, 1A10, 2A1, 2A2, 2A3, 2B4, 2B7, and 2B17 all exhibited glucuronidating activity against both l- and d-menthol. In human liver microsomes, both l- and d-menthol inhibited the formation of each NNAL-Gluc, with a stereospecific difference observed between the formation of (R)-NNAL-O-Gluc and (S)-NNAL-O-Gluc in the presence of d-menthol but not l-menthol. With the exception of three nonmenthol cigarette smokers, urinary MG was detected in all menthol and nonmenthol smokers, with l-MG comprising >98% of total urinary MG. Levels of urinary NNAL-N-Gluc were significantly (P < 0.05) lower among subjects with high levels of total urinary MG; no significant changes in free NNAL were observed. These data suggest that the presence of menthol could lead to increases in alternative, activating metabolic pathways of NNAL in tobacco target tissues, increasing the opportunity for NNAL to damage DNA and lead to the development of tobacco-related cancers. SIGNIFICANCE STATEMENT: High levels of the major menthol metabolite, menthol-glucuronide, was observed in the urine of smokers of either menthol or nonmenthol cigarettes. The fact that a significant inverse correlation was observed between the levels of urinary menthol-glucuronide and NNAL-N-glucuronide, a major detoxification metabolite of the tobacco carcinogen, NNK, suggests that menthol may inhibit clearance of this important tobacco carcinogen.

10.
Cancer Epidemiol ; 63: 101615, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31586822

RESUMO

BACKGROUND: Tobacco use is a well-established risk factor for head and neck cancer (HNC). However, less is known about the potential impact of exposure to tobacco at an early age on HNC risk. METHODS: We analyzed individual-level data on ever tobacco smokers from 27 case-control studies (17,146 HNC cases and 17,449 controls) in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random-effects logistic regression models. RESULTS: Without adjusting for tobacco packyears, we observed that younger age at starting tobacco use was associated with an increased HNC risk for ever smokers (OR<10 years vs. ≥30 years: 1.64, 95% CI: 1.35, 1.97). However, the observed association between age at starting tobacco use and HNC risk became null after adjusting for tobacco packyears (OR<10 years vs. ≥30 years: 0.97, 95% CI: 0.80, 1.19). In the stratified analyses on HNC subsites by tobacco packyears or years since quitting, no difference in the association between age at start and HNC risk was observed. CONCLUSIONS: Results from this pooled analysis suggest that increased HNC risks observed with earlier age at starting tobacco smoking are largely due to longer duration and higher cumulative tobacco exposures.

11.
Mol Pharmacol ; 96(6): 674-682, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31554697

RESUMO

The UDP-glucuronosyltransferase (UGT) family of enzymes is important in the metabolic elimination of a variety of endogenous compounds such as bile acids, steroids, and fat-soluble vitamins, as well as exogenous compounds including many pharmaceuticals. The UGT2B subfamily is a major family of UGT enzymes expressed in human liver. The identification of novel mechanisms including post-transcriptional regulation by microRNA (miRNA) contributes to interindividual variability in UGT2B expression and is a crucial component in predicting patient drug response. In the present study, a high-resolution liquid chromatography-tandem mass spectrometry method was employed to measure UGT2B protein levels in a panel of human liver microsomal samples (n = 62). Concurrent in silico analysis identified eight candidate miRNAs as potential regulators of UGT2B enzymes. Comparison of UGT2B protein expression and candidate miRNA levels from human liver samples demonstrated a significant inverse correlation between UGT2B10 and UGT2B15 and one of these candidate miRNAs, miR-485-5p. A near-significant correlation was also observed between UGT2B7 and miR-485-5p expression. In vitro analysis using luciferase-containing vectors suggested an interaction of miR-485-5p within the UGT2B10 3'-untranslated region (UTR), and significant reduction in luciferase activity was also observed for a luciferase vector containing the UGT2B7 3'-UTR; however, none was observed for the UBT2B15 3'-UTR. UGT2B10 and UGT2B7 activities were probed using nicotine and 3'-azido-3'-deoxythymidine, respectively, and significant decreases in glucuronidation activity were observed for both substrates in HuH-7 and Hep3B cells upon overexpression of miR-485-5p mimic. This is the first study demonstrating a regulatory role of miR-485-5p for multiple UGT2B enzymes. SIGNIFICANCE STATEMENT: The purpose of this study was to identify novel epigenetic miRNA regulators of the UGT2B drug-metabolizing enzymes in healthy human liver samples. Our results indicate that miRNA 485-5p is a novel regulator of UGT2B7 and UGT2B10, which play an important role in the metabolism of many commonly prescribed medications, carcinogens, and endogenous compounds. This study identified potential miRNA-UGT2B mRNA interactions using a novel proteomic approach, with in vitro experiments undertaken to validate these interactions.

12.
Chem Res Toxicol ; 32(8): 1689-1698, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31307193

RESUMO

Tobacco specific nitrosamines (TSNAs) are among the most potent carcinogens found in cigarettes and smokeless tobacco products. Decreases in TSNA detoxification, particularly 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), have been associated with tobacco-related cancer incidence. NNK is metabolized by carbonyl reduction to its major carcinogenic metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which is detoxified by glucuronidation at the nitrogen within the pyridine ring or at the chiral alcohol to form four glucuronide products: (R)-NNAL-O-Gluc, (S)-NNAL-O-Gluc, (R)-NNAL-N-Gluc, (S)-NNAL-N-Gluc. Stereoselective NNAL-Gluc formation and the relative expression of NNAL-glucuronidating UGTs (1A4, 1A9, 1A10, 2B7, 2B10, 2B17) were analyzed in 39 tissue specimens from the upper aerodigestive tract (esophagus (n = 13), floor of mouth (n = 4), larynx (n = 9), tongue (n = 7), and tonsil (n = 6)). All pooled tissue types preferentially formed (R)-NNAL-O-Gluc in the presence of racemic-NNAL; only esophagus exhibited any detectable formation of (S)-NNAL-O-Gluc. For every tissue type examined, UGT1A10 exhibited the highest relative expression levels among the NNAL-O-glucuronidating UGTs, ranging from 36% (tonsil) to 49% (esophagus), followed by UGT1A9 > UGT2B7 > UGT2B17. UGT1A10 also exhibited similar or higher levels of expression as compared to both NNAL-N-glucuronidating UGTs, 1A4 and 2B10. In a screening of cells expressing individual UGT enzymes, all NNAL glucuronidating UGTs exhibited some level of stereospecific preference for individual NNAL enantiomers, with UGTs 1A10 and 2B17 forming primarily (R)-NNAL-O-Gluc. These data suggest that UGTs 1A10 and 2B17 may be important enzymes in the detoxification of TSNAs like NNK in tissues of the upper aerodigestive tract.

13.
J Pharmacol Exp Ther ; 369(2): 234-243, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30850392

RESUMO

UDP-glucuronosyltransferase (UGT) 2A1 is an important enzyme in the detoxification of polycyclic aromatic hydrocarbons found in cigarette smoke. This enzyme is expressed in aerodigestive tract tissues including lung as both its wild-type and exon 4-deleted splice variant isoforms, with the latter acting as a negative regulator of wild-type UGT2A1 activity. UGT2A1 regulation may also be mediated by microRNA (miRNA). To identify miRNA important in the regulation of UGT2A1, expression analysis in tandem with in silico analysis suggested miR-196a-5p and miR-196b-5p as potential top candidates. Significant reductions in firefly luciferase activity were observed in human embryonic kidney cell line 293 cells cotransfected with the wild-type UGT2A1 3'-untranslated region (UTR)-containing luciferase plasmid and either miR-196a-5p (62%, P = 0.00080) or miR-196b-5p (60%, P = 0.00030) mimics. In pull-down assays, there was a 3.4- and 5.2-fold increase in miR-196a-5p (P = 0.054) and miR-196b-5p (P = 0.035), respectively, using the UGT2A1 3'-UTR biotinylated mRNA probe as compared with the ß-actin coding region control mRNA probe. UGT2A1 mRNA was reduced by 25% (P = 0.058) and 35% (P = 0.023) in H146 and H1944 cells, respectively, after overexpression of the miR196a-5p mimic. A similar 32% (P = 0.030) and 41% (P = 0.016) reduction was observed after over-expression of the miR-196b-5p mimic. In H146 cells transfected with miRNA mimic together with a small interfering RNA (siRNA) specific for the UGT2A1 splice variant, a significant reduction in 3-hydroxy-benzo[a]pyrene-glucuronide formation was observed. The miR-196a-5p- and miR-196b-55p-treated cells exhibited reductions of 35% (P = 0.047) and 44% (P = 0.0063), respectively. These data suggest that miR-196a-5p and miR-196b-5p play an important role in UGT2A1 regulation within the lung and potentially other aerodigestive tract tissues.


Assuntos
Glucuronosiltransferase/genética , MicroRNAs/genética , Regiões 3' não Traduzidas/genética , Sequência de Bases , Linhagem Celular Tumoral , Regulação Enzimológica da Expressão Gênica/genética , Glucuronídeos/metabolismo , Glucuronosiltransferase/metabolismo , Humanos
14.
Drug Metab Dispos ; 47(5): 535-544, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30804050

RESUMO

Integrase strand transfer inhibitor (INSTI)-based regimens dominate initial human immunodeficiency virus treatment. Most INSTIs are metabolized predominantly via UDP-glucuronosyltransferases (UGTs). For drugs predominantly metabolized by UGTs, including INSTIs, in vitro data recovered from human liver microsomes (HLMs) alone often underpredict human oral clearance. While several factors may contribute, extrahepatic glucuronidation may contribute to this underprediction. Thus, we comprehensively characterized the kinetics for the glucuronidation of INSTIs (cabotegravir, dolutegravir, and raltegravir) using pooled human microsomal preparations from liver (HLMs), intestine (HIMs), and kidney (HKMs) tissues; human embryonic kidney 293 cells expressing individual UGTs; and recombinant UGTs. In vitro glucuronidation of cabotegravir (HLMs≈HKMs>>>HIMs), dolutegravir (HLMs>HIMs>>HKMs), and raltegravir (HLMs>HKMs>> HIMs) occurred in hepatic and extrahepatic tissues. The kinetic data from expression systems suggested the major enzymes in each tissue: hepatic UGT1A9 > UGT1A1 (dolutegravir and raltegravir) and UGT1A1 (cabotegravir), intestinal UGT1A3 > UGT1A8 > UGT1A1 (dolutegravir) and UGT1A8 > UGT1A1 (raltegravir), and renal UGT1A9 (dolutegravir and raltegravir). Enzymes catalyzing cabotegravir glucuronidation in the kidney and intestine could not be identified unequivocally. Using data from dolutegravir glucuronidation as a prototype, a "bottom-up" physiologically based pharmacokinetic model was developed in a stepwise approach and predicted dolutegravir oral clearance within 4.5-fold (hepatic data only), 2-fold (hepatic and intestinal data), and 32% (hepatic, intestinal, and renal data). These results suggest clinically meaningful glucuronidation of dolutegravir in tissues other than the liver. Incorporation of additional novel mechanistic and physiologic underpinnings of dolutegravir metabolism along with in silico approaches appears to be a powerful tool to accurately predict the clearance of dolutegravir from in vitro data.


Assuntos
Glucuronosiltransferase/metabolismo , Integrases/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular , Criança , Pré-Escolar , Feminino , Células HEK293 , Compostos Heterocíclicos com 3 Anéis/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Rim/metabolismo , Cinética , Fígado/metabolismo , Masculino , Microssomos Hepáticos/metabolismo , Pessoa de Meia-Idade , Piridonas/metabolismo , Raltegravir Potássico/metabolismo , Adulto Jovem
15.
Cancer Epidemiol ; 58: 25-32, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30445228

RESUMO

BACKGROUND: There is inadequate evidence to determine whether there is an effect of alcohol consumption on lung cancer risk. We conducted a pooled analysis of data from the International Lung Cancer Consortium and the SYNERGY study to investigate this possible association by type of beverage with adjustment for other potential confounders. METHODS: Twenty one case-control studies and one cohort study with alcohol-intake data obtained from questionnaires were included in this pooled analysis (19,149 cases and 362,340 controls). Adjusted odds ratios (OR) or hazard ratios (HR) with corresponding 95% confidence intervals (CI) were estimated for each measure of alcohol consumption. Effect estimates were combined using random or fixed-effects models where appropriate. Associations were examined for overall lung cancer and by histological type. RESULTS: We observed an inverse association between overall risk of lung cancer and consumption of alcoholic beverages compared to non-drinkers, but the association was not monotonic. The lowest risk was observed for persons who consumed 10-19.9 g/day ethanol (OR vs. non-drinkers = 0.78; 95% CI: 0.67, 0.91), where 1 drink is approximately 12-15 g. This J-shaped association was most prominent for squamous cell carcinoma (SCC). The association with all lung cancer varied little by type of alcoholic beverage, but there were notable differences for SCC. We observed an association with beer intake (OR for ≥20 g/day vs nondrinker = 1.42; 95% CI: 1.06, 1.90). CONCLUSIONS: Whether the non-monotonic associations we observed or the positive association between beer drinking and squamous cell carcinoma reflect real effects await future analyses and insights about possible biological mechanisms.


Assuntos
Adenocarcinoma/epidemiologia , Consumo de Bebidas Alcoólicas/efeitos adversos , Carcinoma de Células Escamosas/epidemiologia , Neoplasias Pulmonares/epidemiologia , Adenocarcinoma/etiologia , Idoso , Bebidas Alcoólicas/efeitos adversos , Carcinoma de Células Escamosas/etiologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Neoplasias Pulmonares/etiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Inquéritos e Questionários
16.
Cancer Epidemiol Biomarkers Prev ; 28(2): 311-320, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30381441

RESUMO

BACKGROUND: The major mode of metabolism of nicotine is by hydroxylation via cytochrome P450 (CYP) 2A6, but it can also undergo glucuronidation by UDP-glucuronosyltransferases and oxidation by flavin monooxygenases (FMO). The goal of this study was to examine the potential importance of FMOs in nicotine metabolism and assess the potential impact of missense polymorphisms in active FMOs on nicotine-N'-oxide (NOX) formation. METHODS: Urine samples from 106 current Chinese smokers were analyzed for nicotine metabolites by mass spectrometry. Wild-type FMOs 1-5 and their most prevalent nonsynonymous variants were cloned and overexpressed in HEK293 cells, and were tested in oxidation reactions against nicotine. RESULTS: A strong inverse correlation was observed between the ratio of urinary 3'-hydroxycotinine/cotinine, a measure of CYP2A6 activity, and the urinary levels of NOX alone (r = -0.383; P < 0.001) or NOX measured as a ratio of total nicotine metabolites (r = -0.414; P < 0.001) in smokers. In addition to FMO1 and FMO3, the functional FMO2427Q isoform was active against nicotine, whereas FMO4 and FMO5 exhibited low activity against nicotine (K m > 5.0 mmol/L). Significant (P < 0.05) decreases in N'-oxidation activity (V max/K m) were observed for the FMO1I303V, FMO3N61S, FMO3D132H, FMO3V257M, and FMO3E308G variants in vitro when compared with their respective wild-type isoforms; the truncated FMO2Q472stop isoform exhibited no enzyme activity. CONCLUSIONS: These data indicate that increases in nicotine-N'-oxidation occur in subjects with deficient CYP2A6 activity, and that several FMO enzymes are active in nicotine-N'-oxidation. IMPACT: Several common missense FMO variants are associated with altered enzyme activity against nicotine and may play an important role in nicotine metabolism in low-CYP2A6 activity subjects.

17.
Carcinogenesis ; 40(3): 432-440, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-30590402

RESUMO

DNase I hypersensitive sites (DHS) are abundant in regulatory elements, such as promoter, enhancer and transcription factor binding sites. Many studies have revealed that disease-associated variants were concentrated in DHS-related regions. However, limited studies are available on the roles of DHS-related variants in lung cancer. In this study, we performed a large-scale case-control study with 20 871 lung cancer cases and 15 971 controls to evaluate the associations between regulatory genetic variants in DHS and lung cancer susceptibility. The expression quantitative trait loci (eQTL) analysis and pathway-enrichment analysis were performed to identify the possible target genes and pathways. In addition, we performed motif-based analysis to explore the lung-cancer-related motifs using sequence kernel association test. Two novel variants, rs186332 in 20q13.3 (C>T, odds ratio [OR] = 1.17, 95% confidence interval [95% CI]: 1.10-1.24, P = 8.45 × 10-7) and rs4839323 in 1p13.2 (T>C, OR = 0.92, 95% CI: 0.89-0.95, P = 1.02 × 10-6) showed significant association with lung cancer risk. The eQTL analysis suggested that these two SNPs might regulate the expression of MRGBP and SLC16A1, respectively. What's more, the expression of both MRGBP and SLC16A1 was aberrantly elevated in lung tumor tissues. The motif-based analysis identified 10 motifs related to the risk of lung cancer (P < 1.71 × 10-4). Our findings suggested that variants in DHS might modify lung cancer susceptibility through regulating the expression of surrounding genes. This study provided us a deeper insight into the roles of DHS-related genetic variants for lung cancer.

18.
Drug Metab Dispos ; 46(12): 1867-1878, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30257855

RESUMO

Exemestane (EXE) is an aromatase inhibitor used for the prevention and treatment of estrogen receptor-positive breast cancer. Although the known major metabolic pathway for EXE is reduction to form the active 17ß-dihydro-EXE (17ß-DHE) and subsequent glucuronidation to 17ß-hydroxy-EXE-17-O-ß-D-glucuronide (17ß-DHE-Gluc), previous studies have suggested that other major metabolites exist for exemestane. In the present study, a liquid chromatography-mass spectrometry (LC-MS) approach was used to acquire accurate mass data in MSE mode, in which precursor ion and fragment ion data were obtained simultaneously to screen novel phase II EXE metabolites in urine specimens from women taking EXE. Two major metabolites predicted to be cysteine conjugates of EXE and 17ß-DHE by elemental composition were identified. The structures of the two metabolites were confirmed to be 6-methylcysteinylandrosta-1,4-diene-3,17-dione (6-EXE-cys) and 6-methylcysteinylandrosta-1,4-diene-17ß-hydroxy-3-one (6-17ß-DHE-cys) after comparison with their chemically synthesized counterparts. Both underwent biosynthesis in vitro in three stepwise enzymatic reactions, with the first involving glutathione conjugation. The cysteine conjugates of EXE and 17ß-DHE were subsequently quantified by liquid chromatography-mass spectrometry in the urine and matched plasma samples of 132 subjects taking EXE. The combined 6-EXE-cys plus 6-17ß-DHE-cys made up 77% of total EXE metabolites in urine (vs. 1.7%, 0.14%, and 21% for EXE, 17ß-DHE, and 17ß-DHE-Gluc, respectively) and 35% in plasma (vs. 17%, 12%, and 36% for EXE, 17ß-DHE, and 17ß-DHE-Gluc, respectively). Therefore, cysteine conjugates of EXE and 17ß-DHE appear to be major metabolites of EXE in both urine and plasma.


Assuntos
Androstadienos/metabolismo , Inibidores da Aromatase/metabolismo , Neoplasias da Mama , Adulto , Idoso , Idoso de 80 Anos ou mais , Androstadienos/administração & dosagem , Androstadienos/sangue , Androstadienos/urina , Inibidores da Aromatase/administração & dosagem , Inibidores da Aromatase/sangue , Inibidores da Aromatase/urina , Neoplasias da Mama/sangue , Neoplasias da Mama/urina , Cromatografia Líquida , Cisteína/metabolismo , Feminino , Glucuronídeos/metabolismo , Humanos , Desintoxicação Metabólica Fase II , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem
19.
Nat Commun ; 9(1): 3221, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30104567

RESUMO

Genome-wide association studies (GWAS) identified the chromosome 15q25.1 locus as a leading susceptibility region for lung cancer. However, the pathogenic pathways, through which susceptibility SNPs within chromosome 15q25.1 affects lung cancer risk, have not been explored. We analyzed three cohorts with GWAS data consisting 42,901 individuals and lung expression quantitative trait loci (eQTL) data on 409 individuals to identify and validate the underlying pathways and to investigate the combined effect of genes from the identified susceptibility pathways. The KEGG neuroactive ligand receptor interaction pathway, two Reactome pathways, and 22 Gene Ontology terms were identified and replicated to be significantly associated with lung cancer risk, with P values less than 0.05 and FDR less than 0.1. Functional annotation of eQTL analysis results showed that the neuroactive ligand receptor interaction pathway and gated channel activity were involved in lung cancer risk. These pathways provide important insights for the etiology of lung cancer.


Assuntos
Cromossomos Humanos Par 15/genética , Predisposição Genética para Doença , Neoplasias Pulmonares/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética , Reprodutibilidade dos Testes , Fatores de Risco , Fumar/efeitos adversos , Adulto Jovem
20.
J Med Chem ; 61(16): 7065-7086, 2018 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-29995408

RESUMO

Cigarette smoking causes nearly one in every five deaths in the United States. The development of a specific inhibitor of cytochrome P450 2A6 (CYP2A6), the major nicotine-metabolizing enzyme in humans, which could be prescribed for the cessation of cigarette smoking, has been undertaken. To further refine the structure activity relationship of CYP2A6, previously synthesized 3-alkynyl and 3-heteroaromatic substituted pyridine methanamines were used as lead compounds. Isosteric pyridine replacement and appendage of all available positions around the pyridine ring with a methyl group was performed to identify a modification that would increase CYP2A6 inhibition potency, which led to 4g (IC50 = 0.055 mM) as a primary analogue. Potent compounds were evaluated for CYP selectivity, human liver microsomal half-life, and compliance with the rules of five. Top compounds (i.e., 6i, IC50 = 0.017 mM, >120 min half-life) are poised for further development as treatments for smoking and tobacco use cessation.


Assuntos
Citocromo P-450 CYP2A6/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Metilaminas/farmacologia , Microssomos Hepáticos/efeitos dos fármacos , Piridinas/farmacologia , Citocromo P-450 CYP2A6/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Metilaminas/síntese química , Metilaminas/química , Microssomos Hepáticos/enzimologia , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Fumar/tratamento farmacológico , Abandono do Uso de Tabaco
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