Polymorphism of genes encoding drug-metabolizing and inflammation-related enzymes for susceptibility to cholangiocarcinoma in Thailand.

BACKGROUND: Cholangiocarcinoma (CCA) is an intractable cancer, and its incidence in northeastern Thailand is the highest worldwide. Infection with the liver fluke Opisthorchis viverrini (OV) has been associated with CCA risk. However, animal experiments have suggested that OV alone does not induce CCA, but its combination with a chemical carcinogen like nitrosamine can cause experimentally induced CCA in hamsters. Therefore, in humans, other environmental and genetic factors may also be involved. AIM: To examine relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes. METHODS: This hospital-based case-control study enrolled 95 case-control pairs matched by age (± 5 years) and sex. We examined relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes, serum anti-OV, alcohol consumption, and smoking. Polymorphisms of CYP2E1, IL-6 (-174 and -634), IL-10 (-819), and NF-κB (-94) and their co-occurrence with polymorphisms in the drug-metabolizing enzyme gene GSTT1 or GSTM1 were also analyzed. RESULTS: Although CCA risk was not significantly associated with any single polymorphism, persons with the GSTT1 wild-type and CYP2E1 c1/c2 + c2/c2 genotype had an increased risk (OR = 3.33, 95%CI: 1.23-9.00) as compared with persons having the GSTT1 wild-type and CYP2E1 c1/c1 wild genotype. The presence of anti-OV in serum was associated with a 7- to 11-fold increased risk, and smoking level was related to an OR of 1.5-1.8 in multivariable analyses adjusted for each of the seven genetic polymorphisms. CONCLUSION: In addition to infection with OV, gene-gene interactions may be considered as one of the risk factors for CCA development.

A New Method for Breath and Blood Alcohol Determination in Rats Using a Breath Alcohol Meter: An Experimental Study.

Background: The use of police breath alcohol detectors in rat breath alcohol detection experiments has always been a challenge because of the small lung capacity and inability of rats to actively inhale. However, the method of using gas chromatography to detect blood alcohol concentration is time-consuming, complex, relatively expensive, and cannot achieve on-site detection and multi-point unlimited non-invasive detection. Objectives: In this study, a laboratory method was validated for rat breath ethanol concentration (BrAC) measurement to estimate blood ethanol concentration (BAC) in rats. Methods: The rats were placed in a gas collection bottle, the breath sample was drawn out with a syringe, and injected into the mouthpiece of the breath alcohol detector through a rubber tube. The results were immediately detected and automatically converted to BAC. Male rats were randomly divided into three groups. The control group received an intraperitoneal injection of normal saline, the liver injury group received an intraperitoneal injection of 50% Carbon tetrachloride (CCL4 1 mL.kg-1), and the induction group received an intraperitoneal injection of phenobarbital sodium (75 mg.kg-1). Western blot analysis was used to detect the protein expression of CYP2E1. Similar grouping and experimental methods were used for female rats. Results: This method was reproducible. The metabolic activity of CYP2E1 was downregulated in the injury group and upregulated in the induction group, which was consistent with the results obtained for CYP2E1 protein expression. Conclusions: Our results confirmed that the rat gas cylinder breath alcohol assay can be used for multiple detections with immediate and non-invasive determination of alcohol metabolizing capacity. This is important for studies that require repeated assessment of blood alcohol levels.

[Expression of CYP2E1 in different brain regions during the formation of toxic cerebral edema induced by 1, 2-DCE in mice and its effect on cerebral edema formation].

Objective: To study the expression changes of cytochrome P-450 2E1 (CYP2E1) in different brain regions during 1, 2-dichloroethane (1, 2-DCE) exposure, and to explore the effect of CYP2E1 on the influence and effect of brain edema caused by 1, 2-DCE poisoning. Methods: In December 2018, forty female SPF Kunming mice were randomly divided into 4 groups: control group, 1 d, 2 d, and 3 d exposure groups, with 10 mice in each group. Placed in a 100 L static poisoning cabinet (5 animals/cabinet) , inhaled and exposed to the poison at 1.2 mg/L 1, 2-DCE for 3.5 h per day for 1 d, 2 d and 3 d. Except for exposure to 1, 2-DCE, other treatment methods were the same as those in the exposure groups. They were put to death the next day after the end of the poisoning, and the brain tissue was quickly removed and divided into sections. HE staining method was used for different brain regions. Western blotting method was used to detect the protein content of CYP2E1, occludin and claudin5 in different brain regions, real-time fluorescent quantitative PCR method was used to detect the mRNA expression levels of CYP2E1, occludin and claudin5. Histopathological observations were performed, and the kit method was used to detect malondialdehyde (MDA) , reduced glutathione (GSH) content and catalase (CAT) activity in different brain regions. The experimental data were analyzed by SPSS 20.0. One-way analysis of variance (one-way ANOVA) was used for the comparison of multiple groups, and the SNK (q test) method was used for the pairwise comparison between groups.P<0.05 was considered statistically significant. Results: Compared with the control group, histopathological observations showed obvious brain edema in the 2 d and 3 d exposure groups; Compared with the control group, the MDA content, CYP2E1 protein and mRNA expression levels in the cerebellar tissues of the mice in the 3 d exposure group were significantly increased, and the differences were statistically significant (P<0.05) ; Compared with the control group, the GSH content, CAT activity, occludin and claudin5 protein expression levels in the cerebellar tissues of the mice in each exposure group were significantly reduced, and the differences were statistically significant (P<0.05) . There was no significant difference in the above indicators of frontal cortex in each group in mice (P>0.05) . Conclusion: 1, 2-DCE can induce the expression of CYP2E1 in cerebellar tissues of mice, and cause oxidative damage and brain edema, but has no effect on the expression of CYP2E1 in frontal cortex of mice.

Modulation of CYP2E1 metabolic activity in a cohort of confirmed caffeine ingesting pregnant women with preterm offspring.

BACKGROUND: To ascertain interactions of caffeine ingestion, food, medications, and environmental exposures during preterm human gestation, under informed consent, we studied a cohort of Mexican women with further preterm offspring born at ≤ 34 completed weeks. At birth, blood samples were taken from mothers and umbilical cords to determine caffeine and metabolites concentrations and CYP1A2 (rs762551) and CYP2E1 (rs2031920, rs3813867) polymorphisms involved in caffeine metabolism. RESULTS: In 90 pregnant women who gave birth to 98 preterm neonates, self-informed caffeine ingestion rate was 97%, laboratory confirmed rate was 93 %. Theobromine was the predominant metabolite found. Consumption of acetaminophen correlated significantly with changes in caffeine metabolism (acetaminophen R2 = 0.637, p = 0.01) due to activation of CYP2E1 alternate pathways. The main caffeine source was cola soft drinks. CONCLUSION: Environmental exposures, especially acetaminophen ingestion during human preterm pregnancy, can modulate CYP2E1 metabolic activity.

Molecular Docking and Preclinical Study of Five-Membered S,S-Palladaheterocycle as Hepatoprotective Agent.

Purpose: In order to investigate mechanisms underlying the hepatoprotective action of S,Spalladaheterocycle, inhibition of cytochromes P450 has been modeled by molecular docking of four palladaheterocycle stereoisomers to the active sites of an enzymatic oxidase system. To obtain a deeper insight into biochemical aspects providing a basis for the therapeutic effects of five-membered palladacycles (as mixture of stereoisomers), a number of preclinical trials has been conducted Methods: 2D and 3D structures of palladaheterocycle stereoisomers were obtained via converting into SDF files by means of software MarvinSketch. Binding of palladaheterocycle at the active sites of cytochromes P450 2E1 and P450 2C9 has been studied by molecular docking using LeadIT 2.3.2. Hepatoprotective activity of palladaheterocycle at 2.5, 25 and 250 mg/kg doses has been studied based on a model of acute intoxication by CCl4 using in vivo methods. Results: By molecular docking it was identify amino acid fragments responsible for binding with palladacyclic isomers. The tested compound is comparable, in terms of its activity to the hepatoprotective drug SAM according to the in vivo and in vitro experiments such as animal survival data, the efficiency of correction of the cytolytic syndrome, the liver excretory function, carbohydrate, protein and lipid metabolism, and the correction efficiency of the liver antitoxic function (the latter has been determined based on the results of a hexobarbital control experiment). Conclusion: Taking into account results obtained in vivo, in vitro and in silico, it can be concluded that the five-membered S,S-palladaheterocycle effectively protect the liver against acute damage caused by CCl4 , via activation of catalase and glucuronyltransferase, as well as via inhibition of the oxidative stress enzymes.

Urinary and Genetic Biomonitoring of Polycyclic Aromatic Hydrocarbons in Egyptian Coke Oven Workers: Associations between Exposure, Effect, and Carcinogenic Risk Assessment.

BACKGROUND: Coke oven workers are exposed to polycyclic aromatic hydrocarbons (PAHs) with possible genotoxicity and carcinogenicity. Metabolizing enzymes genes and DNA repair genes are suspected to be correlated with the level of DNA damage. They may contribute to variable individual sensitivity to DNA damage induced by PAHs exposure at workplace. OBJECTIVE: To investigate the relationship between biomarkers of PAHs: 1-hydroxypyrene (1-OHP), DNA adducts, and 8-hydroxy-2-deoxyguanosine (8-OHdG) in coke oven workers, and to assess the role of cytochrome P2E1 (CYP2E1) gene expression and DNA repairing gene (XRCC1) polymorphism in detecting workers at risk. METHODS: 85 exposed workers and 85 unexposed controls were enrolled into this study. Urinary 1-OHP, 8-OHdG, and BPDE-DNA adduct were measured. CYP2E1 gene expression and genotyping of XRCC1 399 Arg/Gln were evaluated by real-time PCR. RESULTS: The median urinary 1-OHP levels (6.3 µmol/mol creatinine), urinary 8-OHdG (7.9 ng/mg creatinine), DNA adducts (6.7 ng/µg DNA) in the exposed group were significantly higher than those in the unexposed group. Carriers of the variant allele (Gln) of XRCC1 had the highest levels of 1-OHP, DNA adducts and 8-OHdG, and the lowest level of CYP2E1 gene expression. In exposed workers, significant positive correlations were found between 1-OHP level and each of the work duration, 8-OHdG, and DNA adducts levels. There was a significant negative correlation between 1-OHP level and CYP2E1 gene expression. Work duration and CYP2E1 gene expression were predictors of DNA adducts level; 1-OHP level and work duration were predictors of urinary 8-OHdG level. CONCLUSION: Workers with higher exposure to PAH were more prone to oxidative DNA damage and cancer development. DNA adducts level reflects the balance between their production by CYP2E1 and elimination by XRCC1 gene.

Polimorfismos en los genes de la enzima alcohol deshidrogenasa (ADH1) y la citocromo P450 2E1 (CYP2E1) en pacientes con cirrosis y carcinoma hepatocelular / Polymorphisms in alcohol dehydrogenase (ADH1) and cytochrome p450 2E1 (CYP2E1) genes in patients with cirrhosis and/or hepatocellular carcinoma

Introducción. Uno de los principales factores de riesgo del carcinoma hepatocelular es el consumo crónico de alcohol. En estudios en diferentes poblaciones, se sugiere que las variantes genéticas de las enzimas que participan en el metabolismo del alcohol, como la alcohol deshidrogenasa (ADH) y la citocromo P450 (CYP2E1), estarían asociadas con riesgo de enfermedades hepáticas terminales. Objetivo. Identificar y caracterizar las variantes alélicas de los genes ADH1B, ADH1C y CYP2E1 en pacientes colombianos con diagnóstico de cirrosis y carcinoma hepatocelular. Materiales y métodos. Se incluyeron muestras de pacientes atendidos entre el 2005 y el 2007, y entre el 2014 y el 2016, en la unidad de hepatología de un hospital de Medellín. La genotipificación de las muestras se hizo mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) con análisis de los polimorfismos en la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP). Los resultados se compararon con los de dos grupos de control y con lo reportado en la base de datos del 1000 Genomes Project. Resultados. Se recolectaron 97 muestras de pacientes con diagnóstico de cirrosis y carcinoma hepatocelular. Los dos factores de riesgo más frecuentes fueron el consumo crónico de alcohol (18,6 %) y las colangiopatías (17,5 %). Los genotipos más frecuentes en la población de estudio fueron el ADH1B*1/1 (82 %), el ADH1C*1/1 (59 %) y el CYP2E1*C/C (84 %). Conclusiones. En este primer estudio de los polimorfismos en pacientes colombianos con diagnóstico de cirrosis y carcinoma hepatocelular, los genotipos más frecuentes fueron el ADH1B*1/1, el ADH1C*1/1 y el CYP2E1*C/C. No se observaron diferencias estadísticamente significativas en la frecuencia de los genotipos entre los casos y los controles. Se requieren estudios adicionales en población colombiana para evaluar el riesgo de la enfermedad hepática terminal por consumo crónico de alcohol y la asociación con los polimorfismos.

Introduction: One of the most important risk factors for hepatocellular carcinoma (HCC) is alcohol consumption: Studies in different populations suggest that the risk of liver disease could be associated with genetic variants of the enzymes involved in alcohol metabolism, such as alcohol dehydrogenase (ADH) and cytochrome P450 CYP2E1. Objective: To identify and characterize the allelic variants of ADH1B, ADH1C and CYP2E1 genes in Colombian patients with cirrhosis and/or HCC. Materials and methods: We included samples from patients attending the hepatology unit between 2005-2007 and 2014-2016 of a hospital in Medellin. Samples were genotyped using PCR-RFLP. We compared the results with two control groups and the 1000 Genomes Project database. Results: We collected 97 samples from patients with a diagnosis of cirrhosis and/or HCC. The two main risk factors were chronic alcohol consumption (18.6%) and cholangiopathies (17.5%). The most frequent genotypes in the study population were ADH1B*1/1 (82%), ADH1C*1/1 (59%), and CYP2E1*C/C (84%). Conclusions: This first study of polymorphisms in Colombian patients diagnosed with cirrhosis and/or HCC showed genotypes ADH1B*1/1, ADH1C*1/1 and CYP2E1*C/C as the most frequent. We found no significant differences in the genotype frequency between cases and controls. Further studies are necessary to explore the association between polymorphisms and the risk of end-stage liver disease from alcohol consumption.

Hepatoprotective effect of parthenolide in rat model of nonalcoholic fatty liver disease.

CONTEXT: The active ingredients of traditional medical herbs have been the focus of scientific interests. OBJECTIVE: This study was designed to explore the mechanisms of actions of parthenolide on nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: Thirty-five male Wistar rats were fed high-fat diet (HFD) for eight weeks with or without an intraperitoneal injection of parthenolide to develop NAFLD. Liver triacylglycerol (TG), total antioxidant capacity (TAC), total oxidative status (TOS), thiobarbituric acid reactant substances (TBARs), total thiol groups and tumor necrosis factor alpha (TNF-α) and cytochrome P4502E1 (CYP2E1) levels as well as liver ALT, AST and catalase activities were determined. In addition, quantitative real-time PCR was performed to obtain hepatic gene expression levels of TNF-α, CYP2E1 and nuclear factor-κB (NF-κB). RESULTS: HFD caused a significant weight gain and increased liver TG content as well as alteration in ALT and AST activities, which were attenuated after administration of parthenoide (p < .05). Weakened liver antioxidant system (TAC, total thiol groups and catalase activity) and increased oxidative stress markers (TBARs and TOS) were mainly ameliorated by parthenolide treatment (p < .05). Increased hepatic TNF-α, NF-κB and CYP2E1 at the both gene expression and protein levels were found associated with necroinflammatory changes in histopathological observations and were abrogated almost completely after parthenolide treatment. Oxidative and inflammatory changes observed in HFD fed rats were indicative of NAFLD, which were suppressed with parthenolide treatment. CONCLUSIONS: Based on these results, parthenolide might be a candidate agent for preventing NAFLD due to its anti-inflammatory and anti-oxidative potency.

Mice lacking liver-specific ß-catenin develop steatohepatitis and fibrosis after iron overload.

BACKGROUND & AIMS: Iron overload disorders such as hereditary hemochromatosis and iron loading anemias are a common cause of morbidity from liver diseases and increase risk of hepatic fibrosis and hepatocellular carcinoma (HCC). Treatment options for iron-induced damage are limited, partly because there is lack of animal models of human disease. Therefore, we investigated the effect of iron overload in liver-specific ß-catenin knockout mice (KO), which are susceptible to injury, fibrosis and tumorigenesis following chemical carcinogen exposure. METHODS: Iron overload diet was administered to KO and littermate control (CON) mice for various times. To ameliorate an oxidant-mediated component of tissue injury, N-Acetyl-L-(+)-cysteine (NAC) was added to drinking water of mice on iron overload diet. RESULTS: KO on iron diet (KO +Fe) exhibited remarkable inflammation, followed by steatosis, oxidative stress, fibrosis, regenerating nodules and occurrence of occasional HCC. Increased injury in KO +Fe was associated with activated protein kinase B (AKT), ERK, and NF-κB, along with reappearance of ß-catenin and target gene Cyp2e1, which promoted lipid peroxidation and hepatic damage. Addition of NAC to drinking water protected KO +Fe from hepatic steatosis, injury and fibrosis, and prevented activation of AKT, ERK, NF-κB and reappearance of ß-catenin. CONCLUSIONS: The absence of hepatic ß-catenin predisposes mice to hepatic injury and fibrosis following iron overload, which was reminiscent of hemochromatosis and associated with enhanced steatohepatitis and fibrosis. Disease progression was notably alleviated by antioxidant therapy, which supports its chemopreventive role in the management of chronic iron overload disorders. LAY SUMMARY: Lack of animal models for iron overload disorders makes it hard to study the disease process for improving therapies. Feeding high iron diet to mice that lack the ß-catenin gene in liver cells led to increased inflammation followed by fat accumulation, cell death and wound healing that mimicked human disease. Administration of an antioxidant prevented hepatic injury in this model.

CYP1A1, CYP2E1 and EPHX1 polymorphisms in sporadic colorectal neoplasms.

AIM: To investigate the contribution of polymorphisms in the CYP1A1, CYP2E1 and EPHX1 genes on sporadic colorectal cancer (SCRC) risk. METHODS: Six hundred forty-one individuals (227 patients with SCRC and 400 controls) were enrolled in the study. The variables analyzed were age, gender, tobacco and alcohol consumption, and clinical and histopathological tumor parameters. The CYP1A1*2A, CYP1A1*2C CYP2E1*5B and CYP2E1*6 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The EPHX1 Tyr113His, EPHX1 His139Arg and CYP1A1*2C polymorphisms were detected by real-time PCR. Chi-squared test and binary logistic regression were used in the statistical analysis. Haplotype analysis was conducted using the Haploview program, version 2.05. RESULTS: Age over 62 years was a risk factor for SCRC development (OR = 7.54, 95%CI: 4.94-11.50, P < 0.01). Male individuals were less susceptible to SCRC (OR = 0.55, 95%CI: 0.35-0.85, P < 0.01). The CYP2E1*5B polymorphism was associated with SCRC in the codominant (heterozygous genotype: OR = 2.66, 95%CI: 1.64-4.32, P < 0.01), dominant (OR = 2.82, 95%CI: 1.74-4.55, P < 0.01), overdominant (OR = 2.58, 95%CI: 1.59-4.19, P < 0.01), and log-additive models (OR = 2.84, 95%CI: 1.78-4.52, P < 0.01). The CYP2E1*6 polymorphism was associated with an increased SCRC risk in codominant (heterozygous genotype: OR = 2.81, 95%CI: 1.84-4.28, P < 0.01; homozygous polymorphic: OR = 7.32, 95%CI: 1.85-28.96, P < 0.01), dominant (OR = 2.97, 95%CI: 1.97-4.50, P < 0.01), recessive (OR = 5.26, 95%CI: 1.35-20.50, P = 0.016), overdominant (OR = 2.64, 95%CI: 1.74-4.01, P < 0.01), and log-additive models (OR = 2.78, 95%CI: 1.91-4.06, P < 0.01). The haplotype formed by the minor alleles of the CYP2E1*5B (C) and CYP2E1*6 (A) polymorphisms was associated with SCRC (P = 0.002). However, the CYP1A1*2A, CYP1A1*2C, EPHX1 Tyr113His and EPHX1 His139Arg polymorphisms were not associated with SCRC. CONCLUSION: In conclusion, the results demonstrated that CYP2E1*5B and CYP2E1*6 minor alleles play a role in the development of SCRC.

CYP2E1 and NQO1 genotypes and bladder cancer risk in a Lebanese population.

Urinary bladder cancer incidence in Lebanon ranks among the highest in the world. Cytochrome P450 2E1 (CYP2E1), NAD(P)H quinone oxidoreductase1 (NQO1), and N-Acetyltransferase1 (NAT1), are drug-metabolizing enzymes (DMEs) involved in the metabolism of carcinogens, such as arylamines and heterocyclic amines, implicated in bladder cancer. The present study attempts to investigate the role of these DMEs genetic polymorphism in bladder cancer risk among Lebanese men. 54 cases and 106 controls were recruited from two hospitals in Beirut. An interview-based questionnaire was administered to assess suspected environmental and occupational risk factors. PCR-RFLP was performed on blood-based DNA samples to determine DMEs genotypes. Associations between bladder cancer and putative risk factors were measured using adjusted odds ratios (ORs) and their 95% confidence intervals (CIs). Results showed CYP2E1 c1/c1, NAT1*14A, and smoking, to be risk factors for bladder cancer. No significant differences in frequency distribution of the NQO1 genotypes were found in cases versus controls. The odds of carrying the CYP2E1 c1/c1 genotype were 4 times higher in cases compared to controls (OR=3.97, 95% CI: 0.48-32.7). The odds of carrying at least one NAT1*14A allele were 14 times higher in cases versus controls (OR=14.4, 95% CI: 1.016-204.9). Our study suggests CYP2E1 c1/c1, NAT1*14A, and smoking, as potential risk factors for bladder cancer in Lebanese. Further studies with larger samples must be conducted to confirm these findings.

Clinicopathologic significance in expressions of cytochrome P450 2E1 and PC cell-derived growth factor in esophageal squamous cell carcinoma / 肿瘤研究与临床

Objective To investigate the relationships and clinicopathologic features of the expressions of cytochrome P450 2E1 (CYP2E1) and PC cell-derived growth factor (PCDGF) in esophageal squamous cell carcinoma (ESCC),and to determine the role of CYP2E1 and PCDGF in angiogenesis.Methods The expression levels of CYP2E1 and PCDGF in 42 surgical cancer specimens and 20 adjacent normal esophageal mucosa specimens from patients with ESCC were detected by immunohistochemistry.Results The positive expression rates of CYP2E1 and PCDGF in ESCC were 83.3 ％ (35/42) and 88.1％ (37/42),respectively,which were obviously higher than those of normal mucosa (P ＜ 0.05).Expression of PCDGF was correlated with the degree of histological differentiation (r =0.444,P ＜ 0.05),depth of tumor invasion (r =0.332,P ＜ 0.05),lymph node metastasis (r =0.476,P ＜ 0.05),and TNM classification (r =0.450,P ＜ 0.05).The expression of CYP2E1 was negatively correlated with tumor tissue differentiation (r =-0.518,P ＜ 0.05),and positively correlated with depth of invasion in ESCC (r =0.388,P ＜ 0.05).The expression of CYP2E1 was related to that of PCDGF in the tumor (r =0.483,P ＜ 0.05).Conclusion The expressions of CYP2E1 and PCDGF are synergistically involved in tumor growth,infiltration andmetastasis.Overexpression of CYP2E1 and PCDGF can be used as the important predictors for evaluating the biological behavior of ESCC and predicting prognosis of patients.

Effects of cefetamet hydrochloride injection on activity of CYP1A2, CYP3A4 and CYP2E1 in liver microsomes of rats / 第二军医大学学报

Objective To study the effect of cefetamet hydrochloride injection on the activity of 3 kinds of cytochrome P450 (CYP450) isoforms (CYP1A2, CYP3A4 and CYP2E1) in rat liver microsomes. Methods The SD rats were randomly divided into two groups: control group and cefetamet hydrochloride (CH) group, with each group containing 3 male rats and 3 female rats. The CH group was injected with cefetamet hydrochloride into the tail vein at 50 mg/(kg • d), twice a day for 7 days. A HPLC method was used for simultaneous determination of the production of metabolites and the degradation of the prototype probe substrates of 3 kinds of CYP450 isoforms, so as to evaluate the activity of hepatic CYP450. The analytical column was Diamonsil C18 column (150 mm X 4. 6 mm, 5 Fm), with the flow rate being 1. 0 mL/min. The mobile phase consisted of methanol (0. 1% formic acid) (A)-water (0. 1% formic acid)(B), 0-5 min; 18%A, 5-10 min; 18%-60%A, 10-15 min: 60%A and detected at 247 nm for determination of CYP1A2 activities; methanol (A)-water (0. 02% formic acid)(B), 0-11 min: 40%-60%A and detected at 223 nm for determination of CYP3A4 activities; and methanol (A)-water, 0-10 min: 37%-75%A and detected at 287 nm for determination of CYP2E1 activities. Results Probe substrates and their metabolites showed good linearity within the determining range (r≥0. 999 7). The precision of the method was 0. 05). Conclusion CH injection can significantly induce hepatic microsome CYP3A4 expression in SD rats, but has no induction or inhibition effect on CYP1A2 and CYP2E1, indicating that potential drug-drug interaction might occur when CH injection is coadministered with drugs metabolized by CYP3A4.

A relationship between genetic polymorphisms of CYP2E1 and susceptibility of acute leukemia in Gansu population / 肿瘤研究与临床

Objective To study the relationship between genetic polymorphisms of CYP2E1 and the susceptibility of the acute leukemia in Gansu population. Methods The C609T polymorphism of CYP2E1 gene was detected by polymerase chain reaction-ligase detection reaction (PCR-LDR) and 1∶1 matched casecontrol method in 100 healthy persons (control group) and 100 patients with acute leukemia (AL group).Results The C2 allele genotype and C1C2/C2C2 genotype of CYP2E1 gene occurred more frequently in AL group (13.5 % and 22 %, respectively) than those in control group (10.5 % and 19 %, respectively), however,both differences showed no statistical significant. Further stratified analysis, the C1C2/C2C2 genotype of CYP2E1 gene occurred more frequently in AML group (27%) than that in control group (19 %), but difference had no statistical significant, too. The occurrence frequency of the C2 allele genotype and C1C2/C2C2 genotype of CYP2E1 gene showed no significant difference in ALL group and control group (x2=0.446, P =0.504>0.05). Conclusion Genetic polymorphisms of CYP2E1 don't correlated to susceptibility of acute leukemia(AML and ALL) in Gansu population.

Acetoaminophen-induced accumulation of 8-oxodeoxyguanosine through reduction of Ogg1 DNA repair enzyme in C6 glioma cells

Large doses of acetaminophen (APAP) could cause oxidative stress and tissue damage through production of reactive oxygen/nitrogen (ROS/RNS) species and quinone metabolites of APAP. Although ROS/RNS are known to modify DNA, the effect of APAP on DNA modifications has not been studied systematically. In this study, we investigate whether large doses of APAP can modify the nuclear DNA in C6 glioma cells used as a model system, because these cells contain cytochrome P450-related enzymes responsible for APAP metabolism and subsequent toxicity (Geng and Strobel, 1995). Our results revealed that APAP produced ROS and significantly elevated the 8-oxo- deoxyguanosine (8-oxodG) levels in the nucleus of C6 glioma cells in a time and concentration dependent manner. APAP significantly reduced the 8- oxodG incision activity in the nucleus by decreasing the activity and content of a DNA repair enzyme, Ogg1. These results indicate that APAP in large doses can increase the 8-oxodG level partly through significant reduction of Ogg1 DNA repair enzyme.

Association Between Polymorphisms of Ethanol-Metabolizing Enzymes and Susceptibility to Alcoholic Cirrhosis in a Korean Male Population

Alcohol is oxidized to acetaldehyde by alcohol dehydrogenase (ADH) and cytochrome P-4502E1 (CYP2E1), and then to acetate by aldehyde dehydrogenase (ALDH). Polymorphisms of these ethanol-metabolizing enzymes may be associated with inter-individual difference in alcohol metabolism and susceptibility to alcoholic liver disease. We determined genotype and allele frequencies of ALDH2, CYP2E1, ADH2, and ADH3 in male Korean patients with alcoholic cirrhosis (n=56), alcoholics without evidence of liver disease (n=52), and nondrinkers (n=64) by using PCR or PCR-directed mutagenesis followed by restriction enzyme digestion. The prevalences of heterozygous ALDH2*1/*2 plus homozygous ALDH2*2/*2 in patients with alcoholic cirrhosis (7.1%) and alcoholics without evidence of liver disease (3.8%) were significantly lower than that in nondrinkers (45.3%). The c2 allele frequencies of the CYP2E1 in alcoholic cirrhosis, alcoholics without evidence of liver disease, and nondrinkers were 0.21, 0.20, and 0.20, respectively. Allele frequencies of ADH2*2 in the three groups were 0.78, 0.74, and 0.77 and those of ADH3*1 were 0.94, 0.98, and 0.95. Therefore, we confirmed the observation that the ALDH2*2 gene protects against the development of alcoholism. However, the development of cirrhosis in Korean alcoholic patients was not associated with polymorphisms of ethanol-metabolizing enzymes.