• Toxicological Research
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• v.16 no.4
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• pp.285-291
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• 2000

So far, investigation of environmental pollution has been achieved in field study. This remains the most exhaustive approach, current dimensions of environmental researches and their inherent complexity require that relatively inexpensive and simple laboratory procedures are developed to make possible the screening of large numbers of sites and samples. At this point. microbioassay has been high-lighted. The purpose of this study is to evaluate the water pollution using microbioassay. Two microbioassay methods were optimized and validated for the sensitive and quantitative determination of total toxic effects in the water. EROD(Ethoxyresorufin-O-deethylase) microbioassay was focused to detect PARs, PCBs and dioxinlike components in the water and E-screen assay to xenoestrogens. The EROD microbioassay was executed in rat hepatoma cell line, H4IIE and E-screen assay in MCF7-BUS cell line. Kumho river was selected for this study. 5ι of river water was extracted using combined solid-phase extraction in static adsorption mode with soxhlet extraction. Pollutants adsorbed to the XAD-4 resin were recovered by elution with ethyl acetate and methylene chloride (1 : 9). Toxic effects of extracts were determined by EROD-microbioassay and E-screen assay. EROD activities of water samples were 7.24-72.24 ng/ι MEQ. The estrogenic effect of various water samples is quantitatively evaluated by EEQ. The EEQ of samples range from 0.05 to 6.07 ng-EEQ/ι. These results suggested that Kumho river was highly polluted with organic toxic chemicals.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.81-81
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• 1997

We previously demonstrated an enhancer-like positive regulatory element within a 259-bp sequence (-2352 to-2094 bp) of the human CYP1A2 gene in HepG2 cells. Three protein binding sites were identified by DNase I footprint analyses within the 259-bp sequence: protected region A PRA ( -2283 to-2243 bp), PRB (-2218 to-2187 bp), and PRC (-2124 to-2098 bp) (I. Chung and E. Bresnick, Mol. Pharmacol. 47, 677-685, 1995). In the present study, the functional significance of those protected regions was examined. Transfection experiments with deletion and substitution mutants defined the PRB and PRC as containing positive and negative regulatory elements, respectively. Human breast carcinoma MCF-7 cells were cotransfected with a hepatocyte nuclear factor-1 (HNF-1) expression vector and CYP1A2 promoter-or thymidine kinase promoter-luciferase remoter gene constructs. HNF-1, which contributes to the liver specificity of genes, enhanced reporter gene activity in a PRC sequence-dependent manner. These results suggested that PRC could exist bound to a repressor which was displaceable by other transcription factors such as HNF-1. Results obtained by transfection of HepG2 hepatoma cells with various PRB substitution mutant-luciferase gene fusion constructs indicated that the entire sequence of PRB was necessary for promoter activity. Consequently, the regulation of CYP1A3 expression is very complex, requiring a number of both positive and negative regulatory factors.

• Journal of Pharmacopuncture
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• v.10 no.1 s.22
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• pp.121-135
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• 2007

Objectives : This study was carried out to examine protective effect of wild ginseng extract on HepG2 human hepatoma cell line against tert-Butyl hydroperoxide (t-BHP)-induced oxidative damage. Methods : To evaluate protective effect of wild ginseng extract against t-BHP induced cytotoxicity, LDH level and activity of glutathione peroxidase and reductase were measured. Gene expression was also measured using DNA microarray. Results : Wild ginseng extract showed a significant protective effect against t-BHP-induced cytotoxicity in HepG2 cell line. It is not, however, related with the activities of glutathione peroxidase and glutathione reductase. Analysis of gene expression using DNA chip, demonstrated that 28 genes were up-regulated in t-BHP only group. Five genes - selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, serfiredoxin 1 homolog - may be related with the protective effect of wild ginseng extract. Conclusions : Based on the results, a protective effect of wild ginseng extract against t-BHP-induced oxidative damage in HepG2 cell line is not associated with the activities of glutathione peroxidase and glutathione reductase, but with the expression of selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, and serfiredoxin 1 homolog.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1193-1196
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• 2014

Senescence marker protein 30 (SMP30), a hepatocellular carcinoma (HCe) associated antigen had been identified by our research group. To study its mechanisms of regulation and associations with the occurrence and development of HCe, we inhibited expression by RNAi technique, and observed effects on the biological characteristics of Hep G2 cells. In cell viability assays, cell growth in the experimental group (with siRNA transfection) was elevated. In Transwell invasion assays, compared with blank and control groups, numbers of invading cells in the experimental group were significantly increased, whereas in apoptosis assays, the percentage apoptosis demonstrated no differences, but after UV irradiation, that in the experimental group was higher than the other two groups. In a word, SMP30 can inhibit the proliferation and invasion of human hepatoma cells and thus can be regarded as a cancer suppressive factor.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.4
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• pp.187-191
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• 2002

Tamoxifen, an antiestrogen, has previously been shown to induce apoptosis in HepG2 human hepatoblastoma cells through activation of the pathways independent of estrogen receptors, i.e., intracellular $Ca^{2+}$ increase and generation of reactive oxygen species (ROS). However, the mechanism of tamoxifen to link increased intracellular $Ca^{2+}$ to ROS generation is currently unknown. Thus, in this study we investigated the possible involvement of calmodulin, a $Ca^{2+}$ activated protein, and $Ca^{2+}$/calmodulin-dependent protein kinase II in the above tamoxifen-induced events. Treatment with calmodulin antagonists (calmidazolium and trifluoroperazine) or specific inhibitors of $Ca^{2+}$/calmodulin-dependent protein kinase II (KN-93 and KN-62) inhibited the tamoxifen-induced apoptosis in a dose-dependent manner. In addition, these agents blocked the tamoxifen-induced ROS generation in a concentration-dependent fashion, which was completely suppressed by intracellular $Ca^{2+}$ chelation. These results demonstrate for the first time that, despite of its well-known direct calmodulin-inhibitory activity, tamoxifen may generate ROS and induce apoptosis through indirect activation of calmodulin and $Ca^{2+}$/calmodulin-dependent protein kinase II in HepG2 cells.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1482-1485
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• 2012

A natural furan derivative was isolated from the methanolic extract of the fruit bodies of Fomitiporia ellipsoidea. Its chemical structure was elucidated as methyl 3,5-dioxo-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c']difuran-4-carboxylate by means of extensive NMR and MS data analysis, and named as fomitiporiaester A (1). Compound 1 showed significant antitumor activity to hepatoma $H_{22}$ in vivo, and the inhibition rates were 42.94%, 49.17%, and 58.15% at concentrations of 5, 10, and 20 mg/kg, respectively. Compound 1 showed weak cytotoxic activities against the human hepatoblastoma (HepG-2) and human oophoroma (Skov 3) cell lines with$IC_{50}$ values of more than $100{\mu}M$.

• Mycobiology
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• v.30 no.4
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• pp.213-218
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• 2002

The induction of NAD(P)H: quinone oxidoreductase(QR), glutathione S-transferase(GST), and glutathione(GSH) levels in hepa1c1c7 cells(murine hepatoma) by waxy brown rice cultured with Phellinus igniarius to induce anticarcinogenic enzymes were measured. In addition, the inhibition of polyamines metabolism was tested with the growth of Acanthamoeba castellanii. The result shows that QR, GST activities, and GSH levels of experimental animals were increased much more by feeding the methanol extract of waxy brown rice cultured with Phellinus igniarius than those of the rats received the ethanol of uncultured brown rice. The growth of A. castellanii was inhibited mostly at 40 mg/3 ml concentration of methanol extract of waxy brown rice cultured with P. gniarius. The results suggested that waxy brown rice cultured with P. igniarius possess chemopreventive activity by inducing anticarcinogenic enzymes and inhibiting polyamine metabolism.

• Journal of Gastric Cancer
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• v.2 no.1
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• pp.29-32
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• 2002

A gastroduodenostomy is the most physiological reconstruction after a distal gastrectomy. However, a gastroduodenostomy with either sutures or staples has many complications. These include bleeding, leakage and stenosis. A sutureless gastroduodenostomy with a biofragmentable anastomosis ring (BAR) in was used adenocarcinoma patients to prevent these complications from 1999. A BAR is composed of polyglycolic acid and Barium sulfate to allow for X-ray visualization. Hardy in first introduced the BAR in 1985. Since then, it has been used in an anastomosis of the colon or small bowel surgery but its use in a gastroduodenostomy is the first trial in the world. A 70 year male patient, old who received a subtotal gastrectomy (Billroth I), underwent a A sutureless gastroduodenostomy with a BAR. The gastroduodenostomy with the BAR was watertight and maintained the initial burst strength in the gastrografin X-ray study performed at the postoperative 1 week. The BAR began to fragment 3 weeks after the operation and disappeared from the digestive tract completely. The diameter of the anastomosis site was sufficient for passed foods. No other secondary changes from remained foreign bodies were found in the endoscopic examination. In a second operation to treat a primary hepatoma, there was no adhesive changes around the gastroduodenostomy site. In conclusion, a sutureless gastroduodenostomy with BAR is a safe, easy and efficient reconstructive method after a distal gastrectomy.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.297-302
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• 2003

Cnidii Rhizoma water extract (CRW) was tested for liver cancer chemopreventive potential by measuring the inhibition of phase I enzyme and benzo[a]pyrene-DNA adduct formation and induction of phase II detoxification enzymes. There was 17.0% inhibition in the activity of cytochrome P450 1A1 enzyme with the treatment of 150 mg/ml CRW. At concentration of 30 mg/ml CRW, the binding of $[^3H]B[a]P$ metablites to DNA of NCTC-clone 1469 cell was inhibited by 33.3%. CRW was potent inducer of quinone reductase (QR) and glutathione S-transferase (GST) activities in cultured murine hepatoma Hepalc1c7 cells. However, hepatic glutathione (GSH) level was not influenced by CRW. These findings suggest that CRW has chemopreventive potential of liver cancer by inhibiting cytochrome P450 1A1 activity and benzo[a]pyrene-DNA adduct formation and inducing QR and GST activities.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4235-4238
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• 2013

Glucoraphanin is the main glucosinolate found in broccoli and other cruciferous vegetables (Brassicaceae). The objective of the study was to evaluate whether glucoraphanin and its breakdown product sulforaphane, are potent modulators of various phase I and phase II enzymes involved in carcinogen-metabolising enzyme systems in vitro. The glucosinolate glucoraphanin was isolated from cruciferous vegetables and exposed to human hepatoma cell line HepG2 at various concentrations (0-25 ${\mu}M$) for 24 hours. Glucoraphanin at higher concentration (25 ${\mu}M$) decreased dealkylation of methoxyresorufin, a marker for cytochrome P4501 activity; supplementation of the incubation medium with myrosinase (0.018 U), the enzyme that converts glucosinolate to its corresponding isothiocyanate, showed minimal induction in this enzyme activity at concentration 10 ${\mu}M$. Quinone reductase and glutathione S-transferase activities were unaffected by this glucosinolate; however, supplementation of the incubation medium with myrosinase elevated quinone reductase activity. It may be inferred that the breakdown product of glucoraphanin, in this case sulforaphane, is superior than its precursor in modulating carcinogen-metabolising enzyme systems in vitro and this is likely to impact on the chemopreventive activity linked to cruciferous vegetable consumption.