• 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.

• Molecules and Cells
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• v.25 no.2
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• pp.305-311
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• 2008

After successful clinical application, arginine deiminase (ADI) has been proposed to be a new cancer therapeutic. In the present study, we examined the effect of ADI in combination with ionizing radiation (IR) on MCF-7 cell growth and clonogenic cell death. Cell growth was inhibited by IR in a dose-dependent manner and ADI enhanced the radiosensitivity. ADI itself did not suppress the growth of MCF-7 cells due to the high level of expression of argininosuccinate synthetase (ASS), which convert citrulline, a product of arginine degradation by ADI, to arginine. Previously, it was suggested that ammonia, another product of arginine degradation by ADI, is the main cause of the growth inhibition of irradiated hepatoma cells contaminated with ADI-expressing mycoplasma [van Rijn et al. (2003)]. However, we found that ammonia is not the only factor that enhances radiosensitivity, as enhancement was also observed in the absence of ammonia. In order to identify the enhancing effect, levels of ASS and proteins related to the cell cycle were examined. ASS was unchanged by ADI plus IR, but p21 (a CDK inhibitor) was upregulated and c-Myc downregulated. These findings indicate that changes in the expressions of cell cycle proteins are involved in the enhancement of radiosensitivity by ADI. We suggest that ADI is a potential adjunct to cancer therapy.

• YAKHAK HOEJI
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• v.44 no.3
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• pp.283-292
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• 2000

Angelicae gigantis Radix aqua-acupuncture solution (AGRAS) and Angelicae gigantis Radix water-extracted solution (AGRWS) were prepared and tested for their organ toxicities and chemopreventive potentials. The organ-toxicity of AGRAS to male ICR mice was studied by the measurements of glutamic oxaloacetic transaminase (GOT), glutamic pyruvate transaminase (GPT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP-s) activities after injection of AGRAS for 7 days. The activities of GOT GPT and LDH were decreased, but the activity of ALP-s was not changed with AGRAS. When AGRAS was administered once daily for 10 days before the tumor implantation, AGRAS exerted antitumor activity by inhibiting the growth of Ehrich ascites tumor cells (EATC) in viva. The inductions of quinone reductase (QR), glutathione (GSH) and glutathione S-transferase (GST) and inhibition of polyamine metabolism were tested for the chemopreventive potentials of AGRAS and AGRWS. AGRAS was potent inducer of QR activity in murine hepatoma Hepalclc7 cells. In cultured rat Ac2F cells, AGRAS was also significantly induced QR activity GSH levels were increased about 1.3 fold with AGRAS. In addition the activity of GST was increased about 2.5 fold with AGRAS at the concentration of $0.1{\;}{\times}{\;}$. The effects of AGRAS and AGRWS were tested on the growth of Acanthamoeba castellanii. Proliferation of Acanthamoeba castellanii in a broth medium was inhibited by AGRAS and AGRWS at the concentration of $1{\;}{\times}{\;}and{\;}5{\;}{\times}{\;}$, respectively: These results suggest that AGRAS has chemopreventive potential by inducing QR activity increasing GSH and GST levels and inhibition of polyamine metabolism.

• Preventive Nutrition and Food Science
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• v.10 no.4
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• pp.340-343
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• 2005

Induction of NAD(P)H:(quinone-acceptor) oxidoreductase (QR) which promotes obligatory two electron reduction of quinones and prevents their participation in oxidative cycling and thereby the depletion of intracellular glutathione, has been used as a marker for chemopreventive agents. Induction of phase II enzyme is considered to be an important mechanism of cancer prevention. In our previous study, we assessed the quinone reductase QR-inducing activities of 216 kinds of medicinal herb extracts in cultured murine hepatoma cells, BPRc1 and hepalc1c7 cells. Among the 216 herbal extracts tested in that study, extracts from Chrysanthemum zawadskii showed significant induction of QR. In this study, we examined QR-inducing activity of solvent fractions of the herbal extract. The dichloromethane fraction of the herb showed the highest QR induction among the samples fractionated with four kinds of solvents with different polarity. The fraction also significantly induced the activity of glutathione S-transferase (GST), one of the major detoxifying enzymes, at $4{\mu}g/mL\;and\;2{\mu}g/mL$ in hepalc1c7 and BPRc1 cells, respectively. In conclusion, dichloromethane-soluble fraction of Chrysanthemum zawadskii which showed relatively strong induction of detoxifying enzymes merits further study to identify active components and evaluate their potential as cancer preventive agents.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.212-218
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• 1995

A human hepatoma cell line, hep G2, was used to investigate the mechanism of serum cholesterol reduction by ginseng total saponin, ginsenoside-$Rb_1$, - $Rb_2$, and non-saponin fraction (ether extraction). Hep G2 cells were incubated in 10 $\mu\textrm{g}$/ml of cholesterol containing serum free-RPMl1640 medium with various concentration of ginseng components. The amounts of cholesterol in Hep G2 cells were decreased to maximum 51% in total saponin or two ginsenoside-treated groups while there was 137% increase in cholesterol level of control group as compared with that of normal group. Nonsaponin groups did not show the same effect. In order to elucidate the observed changes in the amount of cholesterol, the activity of amyl CoA : cholesterol acyltransferase (ACAT) in groups showing remarkable reduction in cholesterol amount, i.e., total saponin 10-6%, ginsenoside-$Rb_1$ $10^{-4}$%, ginsenoside-$Rb_2$, $10^{-4}$%, and non-saponin fraction $10^{-4}$%, was assayed using [1-$^{-14}C$%]oleic acid as enzyme substrate. The activity of ACAT was increased in all groups tested as compared with that of control group except for non-saponin group cultured in water soluble cholesterol containing medium. The serum cholesterol lowering effects of ginseng components can partially be attributed to the increased hepatocellular ACAT activity.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.766-771
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• 2007

The co-infection with hepatitis B virus (HBV) and hepatitis C Virus (HCV) is associated with a more severe liver disease and increased frequency in the development of hepatocellular carcinoma com-pared to those with single infection. Here, we demonstrated that HBV X protein (HBx) and HCV Core cooperatively up-regulated the level of p53 in human hepatoma HepG2 cells. The elevated p53 subsequently stimulated the expression of proapoptotic Bax whereas it repressed the expression of antiapoptotic Bcl2. These effects, however, were not observed in p53-negative Hep3B cells. Consistently to their cooperative regulation of apoptotic effectors, HBx and HCV Core additively stimulated cisplatin-mediated apoptotic cell death of HepG2 but not of Hep3B cells. These results may help to explain the development of a more severe liver disease in patients co-infection with HBV and HCV as well as some contradictory results on the roles of HBx and Core in apoptosis.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9655-9660
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• 2014

Background: Nigella Sativa (NS) is an herb from the Ranunculaceae family that exhibits numerous medicinal properties and has been used as important constituent of many complementary and alternative medicines (CAMs). The ability of NS to kill cancer cells such as PC3, HeLa and hepatoma cells is well established. However, our understanding of the mode of death caused by NS remains nebulous. The objective of this study was to gain further insight into the mode and mechanism of death caused by NS in breast cancer MCF-7 cells. Materials and Methods: Human breast cancer cells (MCF-7) were treated with a methanolic extract of NS, and a dose- and time-dependent study was performed. The $IC_{50}$ was calculated using a Cell Titer $Blue^{(R)}$ viability assay assay, and evidence for DNA fragmentation was obtained by fluorescence microscopy TUNEL assay. Gene expression was also profiled for a number of apoptosis-related genes (Caspase-3, -8, -9 and p53 genes) through qPCR. Results: The $IC_{50}$ of MCF-7 cells was $62.8{\mu}L/mL$. When MCF-7 cells were exposed to $50{\mu}L/mL$ and $100{\mu}L/mL$ NS for 24h, 48h and 72h, microscopic examination (TUNEL assay) revealed a dose- and time-dependent increase in apoptosis. Similarly, the expression of the Caspase-3, -8, -9 and p53 genes increased significantly according to the dose and time. Conclusions: NS induced apoptosis in MCF-7 cells through both the p53 and caspase pathways. NS could potentially represent an alternative source of medicine for breast cancer therapy.

• 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.

• Journal of Acupuncture Research
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• v.23 no.3
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• pp.177-190
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• 2006

Objectives : It has long been known about the anticancer effect of GRR-HAS, however, it has not been systemically determined the differentially regulated genes by GRR-HAS in cancer cells. The purpose of this study is to screen the GRR-HAS mediated differentially expressed genes in cancer cells such as HepG2 hepatoma cell lines. Oligonucleotide microarray and proteomic approaches were employed to screen the differential expression genes. Methods : GRR~HAS was prepared by boiling and stored at $-70^{\circ}C$ until use. Cells were treated with various concentrations of GRR-HAS (0.1, 0.5, 1.5, 10, $20mg/m{\ell}$) for 24 h. Cell toxicity was tested by MTT assay. To screen the differentially expressed genes in cancer cells, cells were treated with $1.5mg/m{\ell}$ of GRR-HAS. For oligonucleotide microarray assay, total RNA was used for gene expression analysis using oligonucleotide genechip (Human genome Ul33 Plus 2.0., Affimatrix Co.). For proteomic analysis, total protein was analyzed by 2D gel electrophoresis and Q-TOF mass spectrometer. Results : It has no cytotoxic effects on both HepG2 cells in all concentrations(0.1, 0.5, 1.5, 10,$20mg/m{\ell}$). In oligonucleotide microarray assay, the number of more than twofold differentially regulated known genes was 320 with 6 up-regulated and 314 down-regulated genes in HepG2 cells. In proteomic analysis, three spots were identified by 2D-gel electrophoresis and Q-TOF analysis. One down -regulated protein was protein disulfide isomerase and up-regulated proteins were fatty acid binding protein 1 and 14-3-3 gan1lTIa protein by $1.5mg/m{\ell}$ of CRR-HAS. Discussion : This study showed the comprehensive gene expression analysis using oligonucleotide microarray for the screening of GRR-HAS mediated differentially regulated genes. These results will provide a better application of GRR-HAS in cancer field and drug target development.