• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2565-2570
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• 2014

H19 is an imprinted oncofetal gene, and loss of imprinting at the H19 locus results in over-expression of H19 in cancers. Aflatoxin B1(AFB1) is regarded as one of the most dangerous carcinogens. Exposure to AFB1 would most easily increase susceptibility to diseases such as hepatocellular carcinoma(HCC) but any possible relationship between AFB1 and H19 is not clear. In present study, we found that AFB1 could up-regulate the expression of H19 and promote cell growth and invasion by hepatocellular carcinoma HepG2 cells. Knocking down H19 RNA co ld reverse the effects of AFB1 on cell growth and invasion. In addition, AFB1 induced the expression of E2F1 and its knock-down could down-regulate H19 expression and suppress cell growth and invasion in hepatocellular carcinoma HepG2 cells. Furthermore, E2F1 over-expression could up-regulate H19 expression and promote cell growth and invasion, with binding to the H19 promoter being demonstrated by chromatin immunoprecipitation assays (ChIP). In summary, our results suggested that aflatoxin B1could promote cell growth and invasion in hepatocellular carcinoma HepG2 cells through actions on H19 and E2F1.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6417-6421
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• 2015

Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.9-15
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• 2003

The modification of CYP2El activity is a matter of considerable interest because of its role in the metabolic activation of a variety of environmental toxicants. In the present study, the time-course of changes in human CYP2El activities was determined following treatment with solvents (acetone, dimethylsulphoxide or pyridine) using intact HepG2 cells transfected by human CYP2El. Hydroxylation of chlorzoxazone was used for the measurement of CYP2El activity. CYP2E1 protein level was increased upon cultivation of cells in the presence of the solvents for 24 hr. Determination of CYP2El activities after 24 ht cultivation with the solvents demonstrated that acetone or dimethylsulphoxide increased, whereas pyridine inhibited the activities. This differential effect of the solvents on CYP2El activities persisted to subsequent 24 ht. Competitive inhibition study suggested that pyridine has stronger binding affinity to CYP2E1 than acetone or dimethylsulphoxide. These results demonstrate that different binding affinity of the solvents to CYP2El plays important role in determining real CYP2El activity in intact cells after exposure to the solvents. Present study would be helpful in precise understanding of human CYP2El-mediated toxicity.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.80.2-80.2
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• 2003

The nucleoside analogue, L-FMAUS was synthesized from L-FMAU which has been shown to have significant antiviral acitivity against hepatitis B virus (HBV). The anti-HBV activity and toxicity of the L-FMAUS were examined by a cell culture system using a hepatitis B virus (HBV) producing cell line, HepG2 2.2.15. L-FMAUS was assayed for the inhibition of HBV multiplication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells after an 8-day treatment. (omitted)

• Food Science and Biotechnology
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• v.15 no.2
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• pp.312-316
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• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• Natural Product Sciences
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• v.16 no.1
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• pp.6-9
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• 2010

In continuing our search for biologically active compounds from Korean Compositae medicinal plants, we investigated the constituents of the aerial parts of Lactuca indica L. and isolated a phenylpropanoid derivative from its MeOH extract. The chemical structure was characterized by spectroscopic methods, including 1D and 2D NMR to be di-E-caffeoyl-meso-tartaric acid (1). Compound 1 was isolated for the first time from this plant. In this paper, we suggest that the NMR assignment at C-2 of (+)-taraxafolin-B should be corrected. In the human HBV-transfected liver cell line HepG2.2.15, the compound 1 effectively reduced HBV DNA level in the release of mature HBV particles from HepG2.2.15 cultivation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3123-3128
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• 2014

The liver is normally the major site of glucose metabolism in intact organisms and the most important target organ for the action of insulin. It has been widely accepted that insulin resistance (IR) is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). However, the relationship between IR and drug resistance in liver cancer cells is unclear. In the present study, IR was induced in HepG2 cells via incubation with a high concentration of insulin. Once the insulin-resistant cell line was established, the stability of HepG2/IR cells was further tested via incubation in insulin-free medium for another 72h. Afterwards, the biological effects of insulin resistance on adhesion, migration, invasion and sensitivity to cis-platinum (DDP) of cells were determined. The results indicated that glucose consumption was reduced in insulin-resistant cells. In addition, the expression of the insulin receptor and glucose transportor-2 was downregulated. Furthermore, HepG2/IR cells displayed markedly enhanced adhesion, migration, and invasion. Most importantly, these cells exhibited a lower sensitivity to DDP. By contrast, HepG2/IR cells exhibited decreased adhesion and invasion after treatment with the insulin sensitizer pioglitazone hydrochloride. The results suggest that IR is closely related to drug resistance as well as adhesion, migration, and invasion in HepG2 cells. These findings may help explain the clinical observation of limited efficacy for chemotherapy on a background of IR, which promotes the invasion and migration of cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3731-3736
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• 2014

Phytic acid (PA) has been reported to have positive nutritional benefits and prevent cancer formation. This study investigated the anticancer activity of rice bran PA against hepatocellular carcinoma (HepG2) cells. Cytotoxicty of PA (0.5 to 4mM) was examined by MTT and LDH assays after 24 and 48h treatment. Apoptotic activity was evaluated by expression analysis of apoptosis-regulatory genes [i.e. p53, Bcl-2, Bax, Caspase-3 and -9] by reverse transcriptase-PCR and DNA fragmentation assay. The results showed antioxidant activity of PA in Fe3+ reducing power assay ($p{\leq}0.03$). PA inhibited the growth of HepG2 cells in a concentration dependent manner ($p{\leq}0.04$). After 48h treatment, cell viability was recorded 84.7, 74.4, 65.6, 49.6, 36.0 and 23.8% in MTT assay and 92.6, 77.0%, 66.8%, 51.2, 40.3 and 32.3% in LDH assay at concentrations of 1, 1.5, 2.0, 2.5, 3.0, and 3.5mM, respectively. Hence, treatment of PA for 24h, recorded viability of cells 93.5, 88.6, 55.5, 34.6 and 24.4% in MTT assay and 94.2, 86.1%, 59.7%, 42.3 and 31.6%, in LDH assay at concentrations of 1, 2.2, 3.0, 3.6 and 4.0mM, respectively. PA treated HepG2 cells showed up-regulation of p53, Bax, Caspase-3 and -9, and down-regulation of Bcl-2 gene ($p{\leq}0.01$). At the $IC_{50}$ (2.49mM) of PA, the p53, Bax, Caspase-3 and-9 genes were up-regulated by 6.03, 7.37, 19.7 and 14.5 fold respectively. Also, the fragmented genomic DNA in PA treated cells provided evidence of apoptosis. Our study confirmed the biological activity of PA and demonstrated growth inhibition and induction of apoptosis in HepG2 cells with modulation of the expression of apoptosis-regulatory genes.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.451-457
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• 2005

Experimental studies have demonstrated that the triple combination of amantadine (A)/ ursodeoxycholic acid (UDCA, U)/ biphenyl dimethyl dicarboxylate (DDB, D) might have a preferential antiviral effect compared with that observed in interferon-induced antiviral signal pathways, such as those of $STAT1\alpha$ and the 6-16 genes. To confirm the results, this study examined whether th signal transduction for the antiviral activity in HepG2 2.2.15 was induced dependently or independently of interferon. To accomplish this, the correlation between the $STAT1\alpha$ and 6-16 genes, and nitric oxide, for the mediation of the antiviral activity was assessed. The increase in nitric oxide in the UDCA groups suggests that the inhibition of viral gene replication was enhanced by the amantadine combinations (AU and AUD), and might be more effective if incubated for longer periods. It was found that $STAT1\alpha$ was activated by the amantadine combination, although to a lesser extent than that of $interferon-\alpha$, and the primary endpoints examined for the inhibition of gene expression (HBsAg and HBcAg) were remarkably well regulated. This suggests that the amantadine triple, or at least the double, combination had better clinical benefits than those of $IFN-\alpha$ and the nucleoside analogue single treatment. This demonstrates that the amantadine combination might be a substitute for the existing HBV therapy if the results of in vivo and in vitro studies concur.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7527-7532
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• 2014

Saussurea involucrata is a Mongolian medicinal plant well known for its effects in promoting blood circulation, and anti-inflammation and analgesic functions. Earlier studies reported that Saussurea involucrata has anticancer activity. The purpose of this study was to confirm the anticancer activity of an ethanol extract of Saussurea involucrata against hepatic cancer and elucidate its mechanisms of action. Hepatocellular carcinoma cells were tested in vitro for cytotoxicity, AO/EB staining for apoptotic cells, apoptotic DNA fragmentation and cell cycle distribution in response to Saussurea involucrata extract (SIE). The mRNA expression of caspase-3,-9 and Cdk2 and protein expression of caspase-3,-9, PARP, XIAP, Cdk2 and p21 were analyzed through real time PCR and Western blotting. Treatment with SIE inhibited HepG2 cell proliferation dose- and time-dependently, but SIE only exerted a modest cytotoxic effect on a viability of Chang human liver cells. Cells exposed to SIE showed typical hallmarks of apoptotic cell death. Cell cycle analysis revealed that SIE caused G1-phase arrest in HepG2 cells. In conclusion, Saussurea involucrata ethanol extract has potential cytotoxic and apoptotic effects on human hepatocellular carcinoma cells. Its mechanism of action might be associated with the inhibition of DNA synthesis, cell cycle (G1) arrest and apoptosis induction through up-regulation of the protein expressions of caspase-3,-9 a nd p21, degradation of PARP and down-regulation of the protein expression of Cdk2 and XIAP.