• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.132-132
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• 2004

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.190-191
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• 2003

We investigated the effects of gestational and lactational exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the differential induction of CYP1A1 in the levels of protein and gene expression in the liver and brain regions of offspring rats. For this study, pregnant Sprague Dawley rats were orally exposed to TCDD (1 or 10 ng/kg body weight/day) starting at Day 1 of gestation up to Day 20 of postpartum. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10463-10468
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• 2015

Opisthorchis viverrini (Ov) infection is the major etiological factor for cholangiocarcinoma (CCA), especially in northeast Thailand. We have previously reported significant involvement of PI3K/AKT/PTEN and $Wnt/{\beta}$-catenin in human CCA tissues. The present study, therefore, examined the expression and activation of PI3K/AKT/PTEN and $Wnt/{\beta}$-catenin signaling components during Ov-induced cholangiocarcinogenesis in a hamster animal model. Hamsters were divided into two groups; non-treated and Ov plus NDMA treated. The results of immunohistochemical staining showed an upregulation of PI3K/AKT signaling as determined by elevated expression of the $p85{\alpha}$-regulatory and $p110{\alpha}$-catalytic subunits of PI3K as well as increased expression and activation of AKT during cholangiocarcinogenesis. Interestingly, the staining intensity of activated AKT (p-AKT) increased in the apical regions of the bile ducts and strong staining was detected where the liver fluke resides. Moreover, PTEN, a negative regulator of PI3K/AKT, was suppressed by decreased expression and increased phosphorylation during cholangiocarcinogenesis. We also detected upregulation of $Wnt/{\beta}$-catenin signaling as determined by increased positive staining of Wnt3, Wnt3a, Wnt5a, Wnt7b and ${\beta}$-catenin, corresponded with the period of cholangiocarcinogenesis. Furthermore, nuclear staining of ${\beta}$-catenin was observed in CCA tissues. Our results suggest the liver fluke infection causes chronic inflammatory conditions which lead to upregulation of the PI3K/AKT and $Wnt/{\beta}$-catenin signaling pathways which may drive CCA carcinogenesis. These results provide useful information for drug development, prevention and treatment of CCA.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3881-3885
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• 2015

Obesity markedly increases the risk of colorectal cancer. Recently, the preventive effects of edible mushrooms on triglyceride elevation and visceral fat accumulation have been reported. Here, the effects of Pleurotus eryngii (Eringi) and Hypsizygus marmoreus (Bunashimeji) on azoxymethane (AOM)-induced aberrant crypt foci (ACF; precancerous lesions) in the colorectums of mice fed a high-fat diet were examined. Eringi (ER) and Bunashimeji (BU) mushroom powder samples were used. Six-week-old male C57BL/6J mice received an intraperitoneal injection of AOM (10 mg/kg) once a week for two weeks, and were sacrificed and dissected at 6 weeks after the start of the experiment. After the initiation of the experiment, they received a normal diet (ND), high-fat diet (HFD), HFD + ER (1 or 5% of diet), or HFD + BU (1 or 5% of diet). As a result, body and fat weights were significantly lower in the 5% ER and BU groups than in the HFD group. Liver triglyceride levels were also significantly lower in the 5% ER and BU groups. Total liver cholesterol levels were significantly lower in the 5% ER group. The numbers of ACF (especially large ACF) showed strong inhibitory effects in both ER and BU groups. Measurement of the cell proliferation marker Ki-67 labeling index in the colonic mucosa demonstrated more significant suppression in both ER and BU groups than in the HFD group. These results suggest that the simultaneous intake of ER and BU may inhibit colorectal tumorigenesis in HFD-fed mice.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.99-107
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• 1998

Numerous studies have demonstrated a negative association between cigarette smoking and Parkinson's disease. The present study was undertaken to investigate whether chronic exposure of mice to cigarette smoke a(footed the metabolism of 1-methyl-1113,6-tetrahydro-pyridine (MPTP) by cytochrome P4SO (P-450) or flavin-containing monooxygenase (FMO) in the hepatic microsomes of C57BL6/J mice. Adult male C57BL6/J mice were exposed to mainstream smoke generated from 15 cigarettes for 10 min a day and 5 day per week for 6 weeks. MPTP (10 mg/kg body weight) was administered to mice by subcutaneous injection for 6 consecutive days. Microsolnal P-450 content was increased by MPTP, smoke exposure, or both, but NADPH cytochrome P-450 reductase activity was rather decreased by the same treatments. The activities of benzo(a)pyrene hydroxylase, 7-ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase were significantly increased by the exposure of cigarette smoke, but were not or little affected by MPTP treatment. Benzphetamine N-demethylase activity was not affected either by MPTP treatment or by cigarette smoke exposure, but it was significantly increased by the combined MPTP treatment with cigarette smoke exposure, showing their synergic effect for the induction of the enzyme activity. Interestingly, in vitro studies of hepatic FMO and P-450 system both O-oxygenation and N-demethylation of MPTP were increased in the smoke-exposed or in the MPTP-treated mice. These results suggest that the enhancement in the N-demethylation as well as O-deethylation of P-450 system and in the N-oxygenation of FMO activity by cigarette smoke exposure in mouse liver may contribute to attenuating the neurotoxic effects of MPTP on the nigrostriatal dopaminergic neurons.

• Biomedical Science Letters
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• v.10 no.1
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• pp.35-42
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• 2004

Liver and serum $\beta$-D-mannosidase activities were determined in ethanol intoxicated rats with extrahepatic cholestasis induced by common bile duct ligation (CBD) to manifest the biochemical background of alcohol drinking hazard under the hepatobiliary disease. Liver $\beta$-D-mannosidase activity and its Vmax value in CBD ligated rats with chronic ethanol intoxication were found to be significantly decreased than that in CBD ligation alone. However, the difference of Km value on above hepatic enzyme was not found between the experimental groups. On the other hand, serum $\beta$-D-mannosidase activity in CBD ligated rats with chronic ethanol intoxication was increased more than that in CBD ligation alone. These results indicate that the biosynthesis of the hepatic $\beta$-D-mannosidase decreases and the serum $\beta$-D-mannosidase activity increases in cholestasis combined with chronic ehtanol intoxication, reflecting damage of aggravated hapatocytic membrane. Accordingly, the resulting data supported the fact that alcoholic drinks were enzymologically harmful to the hepatobiliary disease.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.14-20
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• 2009

Matrix metalloproteinases (MMPs) are a group of zinc proteases that serve the function of breaking down extracellular matrix (ECM). The present study evaluated the role of N-acetylcysteine (NAC) on the increased deposition of ECM in hepatic and glomerular fibrosis caused by carbon tetrachloride ($CCl_4$). The activity of MMPs increased and the levels of tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1 and TIMP-2) decreased in the liver and kidney of $CCl_4$-treated rats. Rats treated with $CCl_4$ and NAC showed increased activities of MMPs and decreased levels of TIMP-1 and TIMP-2 in the liver and kidney. Treatment with NAC resulted in the effective degradation of ECM due to an increase in the activities of MMPs and a decrease in the levels of TIMPs.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.79.1-79.1
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• 2008

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.72-72
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.102-102
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• 2000