• Journal of Life Science
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• v.19 no.12
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• pp.1731-1736
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• 2009

Recent studies determined that a chronic western-style diet increased the endogenous small heterodimer partner (SHP) protein levels in mice. In experiments with cell cultures, chenodeoxy cholic acid (CDCA) treatment increased endogenous SHP protein levels and reduced the degradation rate of exogenously expressed flag-SHP levels in the human hepatoma cell line, HepG2 cells. In addition, bile acid-induced intestinal fibroblast growth factor-19 (FGF-19) increased the half-life of the exogenously expressed SHP when HepG2 cells were transfected with ad-flag-SHP. However, both the expression level and the degradation rate of the endogenous SHP in response to cholic acid and FGF-19 have not been well understood, either in mice or in cultured HepG2 cells. This study examined the effects of cholic acid treatment on the endogenous SHP protein levels in mice and the effects of FGF-19 on the degradation rate of the endogenous SHP protein in HepG2 cells. Mice fed 0.5% cholic acid in normal chow showed an increase in endogenous SHP protein levels during both 12 hr and 24 hr treatment periods as compared to control mice fed only normal chow. In cultured HepG2 cells, treatment with CDCA did not noticeably change the rate of degradation in the endogenous SHP protein from cells not treated with CDCA. Although consistent with the previous studies on the exogenous ad-flag-SHP protein, treatment with FGF-19 significantly decreased the degradation rate of the endogenous SHP protein when HepG2 cells were treated with cyclohexamide. These results suggest that both bile acids and FGF-19 increase the endogenous SHP protein levels in mouse liver and HepG2 cells.

• Toxicological Research
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• v.17 no.3
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• pp.215-223
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• 2001

Cadmium is an ubiquitous toxic metal and chronic exposure to cadmium results in the accumulation of cadmium in the liver and kidneys. In contrast, acute exposure leads to damage mainly in the liver. Apoptosis induced by cadmium has been shown in many tissues in vivo and in cultured cells in vitro. However, the molecular mechanism of cadmium-induced apoptosis is not clear in hepatocyte. To investigate the induction of apoptosis in the hepatocyte, we used mouse hepatoma cell line, Hepalclc7 cells, and analysed the molecules that involved in cadmium-induced apoptosis. Cadmium induced the genomic DNA fragmentation, PARP cleavage, and activation of caspase-3 like protease. Caspase-9 cysteine protease was activated in a time-dependent manner but caspase-8 cysteine protease was not significantly activated in cadmium-treated Hepalclc7 cells. Cadmium also induced mitochondrial dysfunction including cytochrome c release from mitochondria, change oj mitochondrial membrane potential tranition, and tranlocation of Bax Protein into mitochondria. These results strong1y indicated that the signal Pathway of apoptotic death in cadmium-treated Hepalclc7 cells is modulated by caspase cascade via mitochondria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.726-731
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• 2000

This study was performed to evaluate the antitumor activities of water and ethanol (EtOH) extract of Salvia miltiorrhiza in vitro and in vivo. The proliferation of the human hepatoma (HepG2), rectum cancer (HRT-18) and colon cancer (HT-29) cells was inhibited by administration of extracts in a dose-dependent manner. Particularly, EtOH extract inhibited proliferation of the cells more effectively than water extract did. The morphology of cells induced by EtOH extract was characterized by reduction of cell size and deformatin. Oral administration of the EtOH extract (3 mg/head) to tumor-bearing mice inhibited the tumor (sarcoma-180) growth by 35% and prolonged their survival rate by 61%. The EtOH extract was shown to be nontoxic at 37.5% mg/head/day on the acute toxicity test. These studies suggest that the EtOH extract of Salvia miltiorrhiza may have antitumor activity in vitro and in vivo.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.261-267
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• 2005

Phase II enzymes are transcriptionally induced by synthetic chemical agents and natural products, and such induction plays critical roles in protection against chemical carcinogens and other toxic xenobiotics. To discover natural products for use as cancer chemopreventive agents, the ability of Citrus aurantium Linn (Jikak) to induce activities of quinone reductase (QR) and glutathione S-transferase (GST) in wild-type murine hepatoma cell line (Hepa 1c1c7) and Ah-receptor-defective mutant of the same cell line (Bprcl) was investigated. Hexane and chloroform fractions of C. aurantium Linn (Jikak) at doses not exhibiting cytotoxicity were effective inducers of QR (${\sim}1.8-fold$) and GST (${\sim}1.5-fold$) in Hepa 1c1c7 cells, whereas showed low QR induction potency in Bprcl cells, which indicates they have weak monofunctional action. Results suggest C. aurantium Linn (Jikak) as potentially useful cancer chemopteventive agent.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.172-178
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• 2009

Fermented ginseng (FG) is an ethanol extract of ginseng radix processed with $\beta$-galactosidase. It was hypothesized that FG may exert anti-hyperlipidemic and anti-diabetic activities through modulating AMP-activated protein kinase (AMPK) in HepG2 human hepatoma cells. In this study, we showed that AMPK phosphorylation was stimulated by FG. These effects were abolished by pretreatment with an AMPK inhibitor, compound C. In addition, FG regulated the expression of genes associated with lipogenesis and lipolysis, thus causing suppression of hepatic triglyceride accumulation. In vivo study using db/db mice, FG reduced fasting plasma glucose, HbAlc, and insulin resistance index, when compared to diabetic control. FG also increased the phospho-AMPK and glucose transporter 4 (GLUT4) expressions in liver and skeletal muscle, respectively. In liver, expressions of lipogenic gene were decreased whereas expressions of lipolytic genes were induced, when compared to diabetic control. Taken together, we may suggest that FG ameliorates hyperglycemia and hyperlipidemia through activation of AMPK and could be developed as a health functional food or therapeutic agent for type 2 diabetic patients.

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.857-862
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• 2004

Naringenin, dietary flavonoid, is antioxidant constituents of many citrus fruits. In the present study, we investigated the effect of naringenin on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1 A 1 gene expression in mouse hepatoma Hepa-1c1c7 cells. Naringenin alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, the TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and naringenin in a dose dependent manner. TCDD-induced CYP1A1 mRNA level was also markedly suppressed by naringenin. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and electrophoretic mobility shift assay revealed that naringe-nin reduced transformation of the aryl hydrocarbons receptor(AhR) to a form capable of specif-ically binding to the DRE sequence in the promoter of the CYP1A1 gene. These results suggest the down regulation of the CYP1A1 gene expression by either naringenin in Hepa-1c1c7 cells might be antagonism of the DRE binding potential of nuclear AhR.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.349-354
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• 2006

The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

• Nutrition Research and Practice
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• v.4 no.5
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• pp.351-355
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• 2010

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of $p27^{kip1}$ (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 ${\mu}M)$ downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 ${\mu}M$ hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-$1{\beta}$), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-$1{\beta}$)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-$1{\beta}$. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.585-590
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• 2003

Activity-guided fractionation of the EtOAc-soluble extract of the whole plants of Sida acuta using a bioassay based on the induction of quinone reductase (OR) in cultured Hepa 1c1c7 mouse hepatoma cells, led to the isolation of ten active compounds of previously known structure, quindolinone (1), cryptolepinone (2), 11-methoxyquindoline (3), N-trans-feruloyltyramine (4), vomifoliol (5), loliolide (6), 4-ketopinoresinol (7), scopoletin (8), evofolin-A (9), and evofolin-B (10), along with five inactive compounds of known structure, ferulic acid, sinapic acid, syringic acid, ($\pm$)-syringaresinol, and vanillic acid. These isolates were identified by physical and spectral data measurement. A new derivative of quindolinone, 5,10-dimethylquindolin-11-one (1a) was synthesized and characterized spectroscopically. Of the active substances, compounds 1-3 and 1a exhibited the most potent QR activity, with observed CD (concentration required to double induction) values ranging from 0.01 to 0.12 $\mu$ g/mL. Six compounds were then evaluated in a mouse mammary organ culture assay, with cryptolepinone (2), N-trans-feruloyltyramine (4), and 5,10-dimethylquindolin-11-one (1a) found to exhibit 83.3, 75.0, and 66.7% inhibition of 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions, respectively, at a dose of 10 $\mu\textrm{g}$/mL.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.218-227
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• 2006

Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.