CYP1A2 is an important cytochrome P450 enzymes, which is involved in metabolism of many clinical drugs and activation of some precarcinogens. CYP1A2 activity can be influenced by various factors including genetic polymorphism, drugs, food and so on, in which the CYP1A2 genetic polymorphism is the basis of difference on the activity and induction of CYP1A2. Therefore,the genotyping of CYP1A2 plays an important part in individualization of therapy.
Carcinogens ; metabolism ; Cytochrome P-450 CYP1A2 ; genetics ; metabolism ; Genotype ; Humans ; Inactivation, Metabolic ; genetics ; Polymorphism, Genetic ; genetics

OBJECTIVETo investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium.

METHODSThe bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method.

RESULTSThe bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation.

CONCLUSIONSThe isolated bacterial consortium can degrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containing wastewater.

Aniline Compounds ; metabolism ; Bacteria ; Biomass ; Bioreactors ; Carcinogens ; metabolism ; Chemical Industry ; Hydrogen-Ion Concentration ; Metals, Heavy ; analysis ; Waste Disposal, Fluid ; methods ; Water Pollutants ; metabolism

Clonorchis sinensis is one of the most prevalent parasitic helminths in Korea. Although cholangiocarcinoma can be induced by C. sinensis infection, the underlying mechanism is not clearly understood. To assess the role of C. sinensis infection in carcinogenesis, an in vitro system was established using the human epithelial cell line HEK293T. In cells exposed to the excretory/secretory products (ESP) of C. sinensis and the carcinogen dimethylnitrosamine (DMN), cellular proliferation and the proportion of cells in the G2/M phase increased. Moreover, the expression of the cell cycle proteins E2F1, p-pRb, and cyclin B was dramatically increased when ESP and DMN were added together. Similarly, the transcription factor E2F1 showed its highest level of activity when ESP and DMN were added simultaneously. These findings indicate that DMN and ESP synergistically affect the regulation of cell cycle-related proteins. Our results suggest that exposure to C. sinensis and a small amount of a carcinogen such as DMN can promote carcinogenesis in the bile duct epithelium via uncontrolled cellular proliferation and the upregulation of cell cycle-related proteins.
Animals ; Carcinogens/*metabolism/*toxicity ; Cell Cycle/drug effects ; Cell Line ; Cell Proliferation ; Clonorchis sinensis/*metabolism ; Dimethylnitrosamine/*toxicity ; Epithelial Cells/*drug effects ; Humans

Adenocarcinoma ; chemically induced ; metabolism ; Animals ; Apoptosis ; drug effects ; Carcinogens ; toxicity ; Histocompatibility Antigens Class I ; metabolism ; Humans ; Interferon-gamma ; metabolism ; Interleukin-2 ; metabolism ; Lung Neoplasms ; chemically induced ; metabolism ; Lymphocytes ; cytology ; metabolism ; Pulmonary Surfactant-Associated Protein C ; metabolism ; Sterigmatocystin ; toxicity

OBJECTIVETo clone differentially expressed cDNA sequences involved in malignant transformation induced by benzo(a)pyrene metabolite dihydroxyepoxy benzo pyrene (BPDE).

METHODThe malignant transformation of human bronchial epithelial cell line 16HBE induced by BPDE in vitro was used as a model for comparing gene expression between the transformed cells and controls. cDNA representational difference analysis (cDNA-RDA) was performed to isolate differentially expressed cDNA fragment in transformed cells. The cDNA fragments were ligated to pGEM-T vector and transformed into JM109 bacteria. The plasmid DNA were sequenced and compared with data in GenBank by BLASTN.

RESULTSFive cDNA sequences were found to be novel ones and were registered in dbest database, which assigned accession numbers in GenBank are BG354691, BG354692, BG354693, BG354694 and BG354695, respectively. Eight of the remaining cDNA sequences showed sequence homology to those previously reported such as ribosomal protein S23, MLN137, ACTN4, transforming growth factor and G protein gene.

CONCLUSIONSThese 13 genes may be involved in BPDE-induced malignant transformation, but their biological characteristics and functions are left to further studies.

Benzopyrenes ; metabolism ; pharmacology ; Carcinogens ; pharmacology ; Cell Transformation, Neoplastic ; chemically induced ; genetics ; Cells, Cultured ; Cloning, Molecular ; DNA, Complementary ; analysis ; drug effects ; DNA, Neoplasm ; analysis ; Gene Expression ; drug effects ; Humans

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent and prevalent nitrosamine procarcinogen found in cigarette smoke. The aim of this work is to study alterations in peroxiredoxin (Prx) expression induced by NNK during carcinogenesis. Characterization of Prx genes from hamster was performed using bioinformatics. V79 cells were induced with different concentrations of NNK (0.1-0.4 mg/mL), and the expression levels of six Prx genes (Prx1-Prx6) were measured by qRT-PCR 24 h following NNK treatment. Prx gene expression was induced by NNK stress, and the highest transcription levels were induced by over 20.42-fold relative to that of the control. NNK induced alterations in Prx expression over the course of lung cancer, which means Prxs may play important roles in ROS detoxification under NNK stress and their functions are complementary.
Animals ; Carcinogens ; administration & dosage ; toxicity ; Cell Line ; Cell Survival ; Cricetinae ; Cricetulus ; Dose-Response Relationship, Drug ; Gene Expression Regulation ; drug effects ; Nitrosamines ; administration & dosage ; toxicity ; Peroxiredoxins ; genetics ; metabolism

The 8-hydroxydeoxyguanosine (8-OH-dG), DNA adduct produced by oxygen radical-induced hydroxylation of C-8 position of guanine residue is accepted as to cause mutation and associate with carcinogenesis, and there are many carcinogens those produce oxygen radicals. Although many carcinogens have been accepted to induce bladder tumor, there is little known about the mechanism of carcinogenesis by these carcinogens. Following administration of bladder carcinogen, N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), 4-Aminobiphenyl (4-ABP), 2-naphthylamine (2-NA) and N-methyl-N-nitrosourea (MNU) to human normal bladder epithelial cell, the results were obtained.1. Following administration of aromatic amine carcinogen, BBN, 4-ABP and 2-NA, the content of 8-OH-dG was increased to about 30-35 % although some variation of time existed according to the kinds of carcinogens. 2. Following administration of MNU, the content of 8-OH-dG was increased to about less than 3 % over all times. 3. Following administration of H2O2 that produce oxygen radicals without metabolism, the content of 8-OH-dG was increased to about 37 %. From this result, it can be supposed that the in crease of 8-OH-dG by carcinogens is induced by oxygen radical.The results obtained suggest that there are some enzymes in bladder epithelium that are related to metabolism of aromatic amine carcinogens and modification of DNA in bladder epithelial cell by the oxygen radicals, that is Formation of 8-OH-dG, is induced in carcinogenesis of bladder tumor byaromatic amine carcinogens.
2-Naphthylamine ; Carcinogenesis ; Carcinogens* ; DNA* ; Epithelial Cells ; Epithelium ; Guanine ; Humans* ; Hydroxylation ; Metabolism ; Methylnitrosourea ; Oxygen ; Reactive Oxygen Species ; Urinary Bladder Neoplasms ; Urinary Bladder*

Epidermal growth factor receptor (EGFR) is a classic protein tyrosine kinase receptor, which plays an important role in cell proliferation, survival, adhesion, differentiation and apoptosis. Abnormality of EGFR and its signaling are closely associated with tumor initiation and development. Many environmental physical and chemical agents can interfere with EGFR and its signal transduction pathways via affecting its phosphorylation, conformation and function, or distribution on cell membrane, finally influencing gene expression and cell fate. This review focuses on the recent progress of above aspects for further understanding of epigenetic mechanisms of cellular stress and carcinogenesis related with environmental agents.
Carcinogens ; Environmental Exposure ; adverse effects ; Environmental Pollutants ; adverse effects ; Humans ; Phosphorylation ; Receptor, Epidermal Growth Factor ; drug effects ; metabolism ; Signal Transduction ; drug effects

Adult ; Carcinogens ; Epoxy Compounds ; poisoning ; Female ; Humans ; Lymphocytes ; drug effects ; metabolism ; Male ; Multivariate Analysis ; Mutation ; drug effects ; Occupational Exposure ; analysis ; Regression Analysis ; Sister Chromatid Exchange ; drug effects

Direct Black 38, a kind of benzidine-based azo dye, is widely used as a dye for fabric, leather, cotton, cellulosic material, paper, wool, silk, and so on. Benzidine-based azo dyes are proven as a mutagen and linked to bladder cancer. In 1978, Natonal Institute for Occupational Safety and Health recommended that three widely used benzidine-based dyes (Direct Black 38, Direct Blue 6, and Direct Brown 95) should be treated as carcinogens. In this experiment, metabolism of the benzidine-based dye. Direct Black 38 was examined by using an isolated liver perfusion system. To measure the metbolites of Direct Black 38,/ 8.0 micrometer, 30.5 micrometer and 63,3 micrometer of Direct Black 38 was added into the recirculating perfusate of the isolated perfused rat liver. Samples were collected at 0, 10, 20, 30, 60, 90. 120 minute. They were treated with sep-pak and methanol, and the metabohtes were detected and quantified with high performance liquid chromatography (HPLC). Residual non-reactive dye in the perfusate and liver was reduced to benzidine and then analyzed by HPLC. Detected metabolites of ?Direct^-Black 38 were benzidine, N-acetylbenzidine, and N,N'-diacetylbenzidine. The average conentration of benzidine was 0.1 micrometer and this concentration was maintained throughout the experimental period. The average concentration of N-acetylbenzidine was 0.22 micrometer and took the same pattern of benzidine. When 30.5 micrometer of Direct BIact 38 was added to the perfusate, only. N,N'-diacetylbenzidin.e increased slightly with time. From the above results we suggest that only small amount of Dirst Black 38 might be metabolized to benzidine regardless of the s, amount of the Direct Black 38. There are some possible explanations. The liver was damaged during the perparation. And the function of the perfused liver decreased rapidly because adsorbing of dye. The benzidine, acetylbenzidine and diacetylbenzidine metabolized to other metabolites were not detected in this experiment.
Animals ; Carcinogens ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Coloring Agents ; Liver* ; Metabolism* ; Methanol ; Occupational Health ; Perfusion ; Rats* ; Silk ; Urinary Bladder Neoplasms ; Wool