• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.985-990
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• 2004

Levans produced from Microbacterium laevaniformans were isolated, characterized, and fractionated by molecular weight. TLC, HPLC, and GC-MS analyses of the exopolysaccharide showed that it was a fructan-type polymer and was composed of (2,6)- and (2,1)-glycosidic linkages. $^{13}C$-NMR analysis proved that the polysaccharide was mainly a $\beta$-(2,6)-linked levan-type polysaccharide. To investigate the cytotoxicity of the acetone-precipitated levan fractions such as M1, M2, and M3, HepG2, P388D1, U937, SNU-1, and SNUC2A cell lines were screened. Among the cell lines tested, the cytotoxicity of M1- M3 fractions were detected from only SNU-1 and HepG2 cells at the dosage level of $100-800\mu\textrm{g}ml$. The M2 fraction M_r$, 80,000) at 400 $mu{g/ml}$ had the greatest cell growth inhibition (84.6%) on SNU-1, while the M1 $(M_r$, 50,000) at $800\mu\textrm{g}ml$ showed the greatest (46.32%) on HepG2. To obtain more uniform M_r$ fractions of levan, the levan was further fractionated from S1 $(M_r$ 1,000,000) to S5 $(M_r$ 10,000) using gel permeation chromatography. Again, the S1-S5 fractions had strong cytotoxicity on SNU-1 and HepG2 cell lines. The greatest inhibition effects of S4 $(M_r$ 80,000) on SNU-1 and S5 $(M_r$ 10,000) on HepG2 were shown to be 49.5% and 73.0%, respectively. The cytotoxicity of the levan fractions was more effective on SNU-1 than on HepG2. Although the relationship between the Mw and the cytotoxicity was not clear, smaller $M_r$, fractions of levan showed greater growth inhibition effect on the cancer cell lines in general. Therefore, it was indicated that a specific Mw class of levan is responsible for the effective cytotoxicity.

• BMB Reports
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• v.30 no.4
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• pp.299-301
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• 1997

The asialoglycoprotein receptor (ASGPR) was the first described mammalian lectin that mediates the specific binding and internalization of galactose/N-acetylgalactosamine-terminating glycoproteins by hepatic parenchymal cells. H1 and H2 are known as essential subunits of the functional ASGPR. There were close similarities in ASGPR H2 subunits between cultured cell line HepG2 and normal human liver cells including identical sequences at both termini. It was therefore expected that there may be some similarities between the subunits from normal liver cells and fetal liver cells. The two subunits of human fetal liver ASGPR. designated FL-H1 and FL-H2. were cloned from cDNA library by peR and the sequences were compared with the known HI and H2 sequences of HepG2, and the H1 sequence of nornal human liver cells. The results showed that FL-H1 was identical to H1 of HepG2. Whereas FL-H2 contains a 15-bp miniexon, but missing 57-bp at the near upstream from the membrane-spanning domain compared to H2 of HepG2 and normal human liver cells indicating that FL-H2 resulted from a differential splicing compared to HepG2 and normal liver cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6073-6076
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• 2012

Discovery of anticancer drugs that kill or disable tumor cells in the presence of normal cells without undue toxicity is a potential challenge for therapeutic care. Several papers in the literature have emphasized the potential implications of marine products such as seaweeds which exhibit antitumor activity. Study attempts to screen the antitumor effect of Sargassum sp, against chosen cell lines such as MCF-7 (Breast cancer) and Hep-2 (Liver Cancer). Ethanol extract of Sargassum sp. was concentrated using a Soxhlet apparatus and dissolved in DMSO. In vitro cytotoxic activity of Sargassum sp at various concentrations ($100{\mu}g/ml-300{\mu}g/ml$) screened for antitumor effect against the chosen cell lines using MTT assay (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole). The study documented that the percentage of cell viability has been reduced with increased concentration, as evidenced by cell death. Sargassum sp extract shows potential cytotoxic activity ($P{\leq}0.05$) with $IC_{50}$ of $200{\mu}g/ml$ and $250{\mu}g/ml$ against Hep-2 and MCF-7 cell lines respectively. The ethanol fraction of Sargassum sp induced cell shrinkage, cell membrane blebbing and formation of apoptotic bodies with evidence of bioactive components as profound influencing factors for anti-tumor effects. Further research need to be explored for the successful application of Sargassum sp as a potent therapeutic tool against cancer.

• 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.

• Molecules and Cells
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• v.38 no.6
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• pp.518-527
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• 2015

Controlled release of medications remains the most convenient way to deliver drugs. In this study, we precipitated gold nanoparticles with quercetin. We loaded gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles (NQ) and tested the biological activity of NQ on HepG2 hepatocarcinoma cells to acquire the sustained release property. We determined by circular dichroism spectroscopy that NQ effectively caused conformational changes in DNA and modulated different proteins related to epigenetic modifications and c ell cycle control. The mitochondrial membrane potential (MMP), reactive oxygen species (ROS), cell cycle, apoptosis, DNA damage, and caspase 3 activity were analyzed by flow cytometry, and the expression profiles of different anti- and pro-apoptotic as well as epigenetic signals were studied by immunoblotting. A cytotoxicity assay indicated that NQ preferentially killed cancer cells, compared to normal cells. NQ interacted with HepG2 cell DNA and reduced histone deacetylases to control cell proliferation and arrest the cell cycle at the sub-G stage. Activities of cell cycle-related proteins, such as $p21^{WAF}$, cdk1, and pAkt, were modulated. NQ induced apoptosis in HepG2 cells by activating p53-ROS crosstalk and induces epigenetic modifications leading to inhibited proliferation and cell cycle arrest.

• Journal of Nutrition and Health
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• v.35 no.4
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• pp.439-445
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• 2002

This study was undertaken to investigate the inhibitory effect of prunus fume extracts on the growth of Hep G2 and HeLa cells. Prunus mums was extracted using the following solvents hexane, chloroform, ethylacetate, methanol, and hot water. The effect on the growth of each cancer cell line was examined by MTT (3-[4, 5-dimethylthiaeol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, cytotoxicity testing, and microscopic observation. The ethylacetate extracts of Prunus muse at the concentration of 250 $\mu\textrm{g}$/ml exhibited the greatest inhibitory effect on the growth of Hep G2 in the MW assay. In cytotoxicity testing, the treatment of the Hep G2 cells with ethylacetate extracts (1000 $\mu\textrm{g}$/ml for 72 hrs) destroyed 75% of the cells, and morphological changes were also observed. futhermore, the hexane extracts of Prunes muse at the concentration of 250 $\mu\textrm{g}$/ml exhibited the greatest inhibitory effect on the growth of HeLa cells in the MTT assay. The treatment of the HeLa cells with the hexane extracts (1000 $\mu\textrm{g}$/ml for 72 hrs) resulted in the destruction of 68% of the cells. Fibroblasts were not affected by either ethylacetate or hexane extracts of prunus muse.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.458-463
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• 1999

This study was undertaken to test for antiviral activity of the aqueous extracts prepared from 4 medicinal plants of Korea (Terminalia chebula, Sanguisorba officinalia, Rubus coreanus, Rheum palmatum). Aqueous extracts were assayed for the inhibition of hepatitis B virus (HBV) replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to $128{\;}\mu\textrm{g}/ml$ and inhibited the production of HBsAg dose-dependently. Among the 4 tested plants, Terminalia chebula exhibits the most prominent anti-HBV activities. Our findings suggest that these 4 medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1361-1364
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• 2008

The inhibitory effects of naringenin, kaempherol, and apigenin on the production of cholesterol in HepG2 KCLB 88065 and MCF-7 KCLB 30022 cells were evaluated. In this study, quercetin was used as a reference reagent. After incubation for 3 days, fat-soluble contents of both cell types were extracted by using the Folch method and the cholesterol contents in both cultured cells were determined by high performance liquid chromatography. The concentration of cholesterol in untreated each tissue cells was $12.2{\pm}0.11$ and $8.83{\pm}0.12\;mg/g$ of lipid, respectively. The total concentration of each flavonoid was adjusted to 0, 35, or $350{\mu}M$ in the culture broth. As the results, the addition of 2% methanol and dimethyl sulfoxide (DMSO) to the media (control for flavonoid solvents) did not significantly affect cell growth; however, DMSO caused an increase in the production of cholesterol. Each flavonoid inhibited the production of cholesterol in both HepG2 and MCF-7 cells at the concentration of $35{\mu}M$ above. In addition, the inhibitory effect of kaempherol on the production of cholesterol in these cells was greater than the other flavonoids tested and HepG2 cells are more sensitive to flavonoids than MCF-7. From the results, the inhibitory effects of flavonoids on cholesterol production are different depending on the cell type.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.372-376
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• 2001

The effect of garlic extract and vitamin C mixture on the various cancer cell lines in vitro and in vivo have been examined. Proliferation of human colon cancer (HT-29), human rectal cancer (HRT-18) and human hepatoma (HepG2) cells was inhibited by garlic extract and vitamin C, respectively. Based on the cytotoxic activity, mixture of garlic extract and vitamin C was demonstrated to possess a synergistic growth inhibition on HT-29, HRT-18 and HepG2 cancer cells. Mixture of garlic extract and vitamin C significantly arrested G2/M phase cells in the HepG2 cell cycle. Oral administration of mixture of garlic extract and vitamin C to sarcoma-180 tumor-bearing mice prolonged survival time compared to that of control group. These results suggested that addition of vitamin C enhances anticancer activity of garlic extract in vitro, and mixture of garlic extract and vitamin C has antitumor effect in vivo.

• Biomedical Science Letters
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• v.18 no.2
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• pp.160-164
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• 2012

The baculovirus/insect cell expression system is of great value for the large-scale production of normal and mutant mammalian passive glucose-transport proteins heterologously for structural and functional studies. In most mammalian cells that express HepG2, this transporter isoform is predominantly located at the cell surface. However, it had been reported that heterologous expression of other membrane proteins using the baculovirus system induced highly vacuolated cytoplasmic membranes. Therefore, how a cell responds to the synthesis of large amounts of a glycoprotein could be an interesting area for investigation. In order to examine the subcellular location of the human HepG2 transport proteins when expressed in insect cells, immunofluorescence studies were carried out. Insect cells were infected with the recombinant baculovirus AcNPVHIS-GT or with wild-type virus at a MOI of 5, or were not exposed to viral infection. A high level of fluorescence displayed in cells infected with the recombinant virus indicated that transporters are expressed abundantly and present on the surface of infected Sf21 cells. The evidence for the specificity of the immunostaining was strengthened by the negative results shown in the negative controls. Distribution of the transporter protein expressed in insect cells was further revealed by making a series of optical sections through an AcNPVHIS-GT-infected cell using a confocal microscope, which permits optical sectioning of cell sample. These sections displayed intense cytoplasmic immunofluorecence surrounding the region occupied by the enlarged nucleus, indicating that the expressed protein was present not only at the cell surface but also throughout the cytoplasmic membranous structures.