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.

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.

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.

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.