Rozprawy doktorskie: „HepG2 cells”

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呂可欣 i Ho-yan Lui. "Effects of lipoic acid on oxidant-induced cytotoxicity in HepG2 cells". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31969768.

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Lui, Ho-yan. "Effects of lipoic acid on oxidant-induced cytotoxicity in HepG2 cells". Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2203240X.

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Vahdati-Mashhadian, Nasser. "Regulation of CYP3A gene expression in human HepG2 hepatoma cells". Thesis, University of Surrey, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364817.

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Colton, Heidi Muth. "Dissecting Mechanisms of Toxicity in HepG2 Cells Using Gene Expression Analysis". NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-09132002-161850/.

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Reduction/oxidation (redox) balance is a critical component of cell viability. When oxidants reach levels that overcome the ability of antioxidants to eliminate them, it results in damage to cellular macromolecules. The damage to DNA, lipids and protein initiates a cascade of physiological events in response to the oxidative stress. Researchers have been studying these cellular responses by analyzing gene expression and protein activity for many years. Recently, new technologies have emerged that allow scientists to analyze the differential expression of extremely large sets of genes in response to oxidative stressors and other toxicants. Most experiments performed to date have involved a single dose of a chemical and a single timepoint for analysis. However, gene expression has proven to be a dynamic process with many transcriptional changes over a relatively short timecourse. In order to study the dynamic nature of gene expression and its effects on cellular physiology, experiments were performed to analyze the effects of oxidative stress on HepG2 cells over a 24 hour timecourse with a range of doses of the glutathione depletor, diethylmaleate (DEM). Using Clontech microarrays, TaqMan RT-PCR, and assays to measure reduced glutathione (GSH) concentrations and to determine cell cycle status, an overall picture of the effects of oxidative stress in relation to dose and time was created. DEM caused GSH depletion to the extent that cells treated with 1.25mM DEM for 4 hours contained less than 20% of the GSH levels in untreated cells. The redox imbalance caused the transcription of genes that initiate cell cycle arrest, DNA repair, and induction of stress proteins. The p53-independent induction of p21 initiated a cascade of events including the decreased transcription of cyclins that resulted in cell cycle arrest. Additionally, the transcription of stress induced genes such as HSP70 and heme oxygenase-1 exhibited significant time and dose-dependent increases in reponse to DEM. While the genes exhibiting differential expression remained generally the same between doses, it was the time taken for these gene changes to occur that varied greatly from the highest dose to the lowest dose of DEM. These experiments demonstrate the importance of analyzing an effective dose range over an extended time period when using differential gene expression to study the mechanisms of toxicity.

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Etwebi, Zienab. "Magnesium Regulation of Glucose and Fatty Acid Metabolism in HEPG2 Cells". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1307564164.

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Wang, Hui. "Molecular mechanisms of oridonin-induced cytotoxicity and apoptosis in HepG2 cells". HKBU Institutional Repository, 2010. http://repository.hkbu.edu.hk/etd_ra/1162.

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Syed, Noor Afshan. "Regulation of glycogen synthase and glycogen phosphorylase by insulin in HepG2 cells". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63926.pdf.

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Portolesi, Roxanne, i roxanne portolesi@flinders edu au. "Fatty acid metabolism in HepG2 cells: Limitations in the accumulation of docosahexaenoic acid in cell membranes". Flinders University. Medicine, 2007. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20070802.103146.

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The current dietary recommendations for optimal health are designed to increase our intake of two bioactive omega-3 (n-3) fatty acids, eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), abundant naturally in fatty fish such as salmon. Health authorities recommend that the general population consume two to three fatty fish meals per week (1) for optimal health and for the prevention of cardiovascular disease. However, some modern Western societies consume only modest amounts of fish and seafood (2;3). Land based vegetable oils may provide an alternative to meet these needs. Linseed and canola oils are rich in alpha-linolenic acid (ALA, 18:3n-3) (4). ALA can be converted endogenously to EPA and DHA and suggests that increasing the dietary intake of ALA may increase the conversion and accumulation of DHA in tissues and plasma. However, elevated dietary intakes of ALA in animals and humans results in an increased level of EPA in tissues yet there is little or no change in the level of DHA (5-7). The current consensus is that the synthesis of DHA from ALA in humans is limited yet the mechanisms involved in regulating the accumulation of DHA in tissues are poorly understood. The reputed rate-limiting enzyme in the conversion of fatty acids is delta 6 desaturase (D6D). ALA is a substrate for D6D and undergoes a series of desaturation and elongation reactions to yield n-3 long chain polyunsaturated fatty acids (LCPUFA). The final step in the synthesis of DHA from ALA involves translocation of its immediate fatty acid precursor, 24:6n-3 from the endoplasmic reticulum to the peroxisome to be partially beta-oxidised to yield DHA. The involvement of multiple enzymes in the desaturation-elongation pathway, and the integration of other pathways, such as phospholipid biosynthesis, suggests there are various steps that may regulate the accumulation of DHA in cell membranes. This thesis aimed to examine the possible regulatory steps in the conversion of fatty acids to LCPUFA, particularly in the synthesis of DHA from n-3 fatty acid precursors. The human hepatoma cell line, HepG2, was used as an in vitro cell system to examine the accumulation of individual fatty acids and their metabolites in isolation from other competing fatty acid substrates. The accumulation of linoleic acid (LA, 18:2n-6) and ALA in HepG2 cell phospholipids following supplementation with increasing concentrations of each respective fatty acid correlated with that described in vivo, as was the accumulation of their conversion products. The accumulation of DHA in cells supplemented with ALA reached a plateau at concentrations above 5 micro g/ml and paralleled the accumulation of 24:6n-3 in cell phospholipids, suggesting that the delta 6 desaturation of 24:6n-3 was prevented by increasing concentrations of ALA, thereby limiting the accumulation of DHA. The accumulation of DHA in cells supplemented with eicosapentaenoic acid (EPA, 20:5n-3) or docosapentaenoic acid (DPA, 22:5n-3) was significantly greater than the level of DHA that accumulated in cells supplemented with ALA. However, regardless of substrate, the level of DHA in cell membranes reached a plateau at substrate concentrations above 5 micro g/ml. This thesis further aimed to examine the effect of fatty acid supplementation on the mRNA expression of D6D in HepG2 cells. The expression and activity of D6D mRNA is subject to nutritional and hormonal regulation. The mRNA expression of D6D in HepG2 cells following supplementation with oleic acid (OA, 18:1n-9), LA, ALA, arachidonic acid (AA, 20:4n-6) or EPA was examined by real time RT PCR. The expression of D6D mRNA was reduced by up to 50% in cells supplemented with OA, LA, ALA , AA or EPA compared with control cells and suggests that fatty acids modulate the expression of the key enzyme involved in the conversion of fatty acids. The effect of fatty acid co-supplementation on the fatty acid composition of HepG2 cell phospholipids was also examined in an attempt to gain insights into the role of D6D and the enzymes involved in peroxisomal beta-oxidation on the accumulation of DHA from n-3 fatty acid precursors. The reduction in the accumulation of DHA in cells co-supplemented with DPA and docosatetraenoic acid (DTA, 22:4n-6) was greater than in cells co-supplemented with DPA and LA, suggesting that peroxisomal beta-oxidation may have a greater role in determining the accumulation of DHA from DPA than the activity of D6D. Further investigation should be directed towards understanding the role that peroxisomal beta-oxidation may play in the synthesis of DHA from precursor fatty acids. The fatty acid composition of cell membranes in vivo is a result of several physiological processes including dietary intake, phospholipids biosynthesis and fatty acid conversion as well as catabolic processes. This thesis demonstrates that a greater understanding of the regulation of the conversion of fatty acids will help to define dietary approaches that enhance the synthesis of n-3 LCPUFA from n-3 fatty acid precursors to lead to improved outcomes for health.

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Morton, Latarchal D. "Ceramide stimulates 3 -methylcholanthrene’s ability to induce cytochrome (cyp1a1) p450 in hepg2 cells". DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2005. http://digitalcommons.auctr.edu/dissertations/3648.

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This study showed that dihydroceramide and ceramide increased the expression of cytochrome (CYP) P450 when HepG2 cells were exposed to 3-methylcholanthrene (MC). Cytochrome P450s are a highly diversified set of heme proteins responsible for drug metabolism, blood homeostasis, cholesterol biosynthesis, and steriodogenesis. CYP1A1, the first P450 isoform to be named, is responsible for the metabolism and biotransformation of polycyclic aromatic hydrocarbons (PAH). 3-methylcholanthrene, an extremely hazardous PAH, has been shown to induce the CYP1A1 gene through the aryl hydrocarbon receptor (AhR) pathway. Past investigations have shown that the sphingolipid, C2-ceramide, induces CYP1A1 expression when HepG2 cells are exposed to 3-methylcholanthrene. Ceramide, the hydrophobic moiety of all complex sphingolipids, is known to act as a second messenger in the cell. Unlike ceramide, dihydroceramide, the precursor of an essential molecule needed for the formation of ceramide through the de novo pathway, has been reported to be biologically inactive. It is hypothesized that structurally different sphingolipids (ceramide and dihydroceramide) modulate the ability of MC to induce CYP1A1 expression by increasing the influx of MC into the cell. To test this hypothesis, CYP1A1 enzyme activity and protein amounts were assessed by the ethoxyresorufm-o-deethylase assay and Western Blot analysis, respectively. Through confocal microscopy it was found that the increased influx of MC was correlated to the increased expression of CYP1A1 in the presence of the sphingolipids when compared to MC treated cells alone. In addition to increased influx, it was found that ceramide and dihydroceramide also caused MC to quickly localize around the nucleus of the cells. An increased influx of MC in cells and localization to the nucleus can lead to the increased expression of CYP1A1 for the biotransformation ofPAHs. This dual effect can potentially enhance the chemical carcinogenesis process through increased production of the carcinogenic metobolites of these PAHs. Sphingolipid stimulation of CYP1A1 enzyme during the biotransformation of a PAH could then enhance the incidence of chemical carcinogenesis.

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To, Wing Shu. "Effect of cellular redox and energy states on benzo[a]pyrene induced modes of death in the hepa and the HepG2 cell lines". HKBU Institutional Repository, 2010. http://repository.hkbu.edu.hk/etd_ra/1173.

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Andreou, Efrosini Roseann. "Analysis of CYP7A1 gene regulation in HepG2 cells by reverse-transcriptase polymerase chain reaction". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29317.pdf.

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Ibbitson, Deanna. "Effects of zinc on retinoic acid-induced growth inhibition in human hepatocarcinoma HepG2 cells". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/40664.

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Retinoic acid (RA), a bioactive metabolite of vitamin A, inhibits growth in a variety of cancer cells including liver cancer. It is thought that this function of RA is achieved by modulating gene expression through complexing with retinoic acid receptors (RARs) and retinoid X receptors (RXRs), two groups of zinc-finger proteins. Zinc deficiency has been shown to affect gene expression and to impair DNA binding ability of zinc-finger proteins. The hypotheses of my thesis research were: 1) sufficient cellular zinc level is important for the effectiveness of RA-induced growth inhibition in hepatocarcinoma HepG2 cells; and 2) the influence of zinc on RA-induced growth inhibition is through modulating expression or function of RARs and RXRs, which in turn affects the expression of their target genes, CYP26a1 and RARβ. The overall objective was to examine the effects of zinc on RA-induced growth inhibition in HepG2 and the possible mechanisms involved. Zinc manipulation was achieved by culturing HepG2 cells for 6 d in low-zinc media supplemented with 0, 5, and 10 μmol/L zinc to mimic low-, adequate-, and high-zinc conditions. Growth in low-zinc media for 6 d reduced total cellular zinc and the labile intracellular pool of zinc by 29 and 86%, respectively. Treating the cells with 35 µM of RA for 12 h following zinc manipulation significantly reduced cell proliferation in all zinc-treatment groups compared to their corresponding RA control, with the greatest reduction in the high-zinc group. Cell cycle analysis showed that the proportion of cells in the S-phase was reduced by RA treatment at 24 and 72 h at all zinc levels, with the greatest reduction in cells cultured in high-zinc medium. Following growth in low-, adequate- and high-zinc medium, RA treatment elevated the abundance of RARβ and Cyp26a1 mRNA equally in all zinc-treatment groups compared to their correspondent RA controls. Growth in low zinc medium increased mRNA abundance of RXRα while RARα, RARβ, RARγ, RXRβ and RARγ were not affected. In conclusion, these results showed that increasing zinc appeared to sensitize HepG2 cells to RA-induced growth inhibition, but had no effect on RA-induced gene expression of CYP26a1 and RARβ.

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Peters, Demia E. "Complex sphingolipid involvement in the expression of CYP1A1 activity in 3-methylcholanthrene-exposed HEPG2 cells". DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2001. http://digitalcommons.auctr.edu/dissertations/2482.

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Polycyclic aromatic hydrocarbons (PAHs), complex organic molecules that are the by-products of carbon-based fuel combustion, are carcinogenic upon biotransformation in the body. Cytochrome P450 1A1 (CYP1A1) is part of the enzyme system primarily responsible for the metabolism and biotransformation of PAHs in humans. In HepG2 cells (a human hepatoma cell line), it has been established previously in this laboratory that 3-methylcholanthrene (MC), a PAH, induces CYP1A1 activity 20 to 30 fold over control values. Also in those studies, MC’s ability to induce this activity was significantly reduced by compounds that inhibit the synthesis of complex sphingolipids. However, addition of the synthetic short-chain sphingolipid C2-ceramide after inducer and inhibitor treatment restored CYP1A1 inducibility. This produced the current laboratory hypothesis that complex sphingolipids are involved in the signal transduction pathway used by MC to induce CYP1A1 activity. This research investigated the role that sphingolipids play in the inducibility of CYP1A1 by MC. Initially, the induction of CYP1A1 was examined by MC as a transcriptional event in these cells. Western blot analysis was used to determine whether CYP1A1 protein amounts fluctuate with CYP1A1 activity per the treatments used. Further studies included quantitative real-time reverse transcriptase PCR to quantitate the amount of CYP1A1 mRNA that resulted from each treatment. It was found that the action of the inhibitor of sphingolipid synthesis seems to be dependent on the presence of a heavy metal. It was also found that C2-ceramide, the prototype complex sphingolipid used, causes synergistic induction of CYP1A1 enzyme activity and that this synergism apparently results from actions at the level of the gene. Thus, it can be concluded that complex sphingolipids are involved in the transcriptional regulation of CYP1A1 expression.

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Davies, Emily Claire. "Green tea extract and its metabolites induce biochemical changes linked to hepatotoxicity in HepG2 cells". Thesis, Davies, Emily Claire (2019) Green tea extract and its metabolites induce biochemical changes linked to hepatotoxicity in HepG2 cells. Honours thesis, Murdoch University, 2019. https://researchrepository.murdoch.edu.au/id/eprint/54595/.

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Green tea has been consumed for thousands of years and its concentrated extract is now a popular herbal supplement frequently consumed in isolation or as part of a multi-ingredient product. Green tea extract (GTE) is commonly used for its wide range of purported health benefits and, as with most herbal supplements, its sale on the Australian market is regulated by the Therapeutic Goods Administration without requiring pre-market safety or efficacy analysis. Unfortunately, GTE has been implicated in over 50 cases of liver damage in the last 20 years, a number of which resulted in transplantation as the only option for patient survival. Despite the clear link between this supplement and liver injury in these individuals, little is currently known in regards to which biochemical pathways are affected during GTE-induced hepatotoxicity and the extent to which this is mediated by metabolic products of GTE. In this study, GTE and individual catechins were metabolised with S9 human liver fraction and subsequently analysed using untargeted metabolomics. The results confirmed that some metabolism of the GTE had occurred, with the production of at least 17 GTE metabolites. Of these suspected metabolites, 10 were also found in the metabolised catechins, suggesting that more than half of these compounds were metabolites of the catechins in GTE. To assess hepatotoxicity, HepG2 cells were exposed to either unmetabolised or metabolised GTE at doses equivalent to 1 mg/mL. Additionally, to assess the impact of GTE on drug-induced liver injury, another group of cells were exposed to 15 mM paracetamol, 1 mg/mL GTE or a combination of both treatments. The exposure period for all treatments was 24 h, after which small molecule metabolites were extracted from harvested cells and analysed using untargeted metabolomics. Changes were observed in amino acids, carbohydrates and fatty acids in all treatment groups, and the same biochemical pathways appeared to be affected in all GTE treatment variations. Cell treatment with GTE metabolites appeared to yield less cytotoxicity than those treated with unmetabolised GTE. It was unable to be determined whether GTE exacerbated paracetamol-induced hepatotoxicity from the results obtained in this study. Overall, the findings from this study suggested that GTE causes disruption to cellular lipids, proteins, nucleic acids and the mitochondria, potentially as a result of oxidative stress. Given the popularity and ready availability of GTE, regulation of herbal supplements containing this product must be improved to ensure consumer safety and ultimately prevent further cases of liver damage.

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Oliveira, Rita de Cássia Silva de. "Avaliação da citotoxicidade, genotoxicidade e mutagenicidade da mandioca (Manihot esculenta Crantz) em célula tumoral HepG2". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/60/60134/tde-27092012-141240/.

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O fator alimentar pode ser considerado um promotor tumorigênico responsável pela etiologia do câncer gástrico no estado do Pará. A mandioca (Manihot esculenta Crantz) é uma das muitas espécies da Amazônia consumida de modo indiscriminado pelos habitantes da região norte. O cianeto, seu principal componente tóxico, pode ser liberado durante o processamento da mandioca por meio da hidrólise do glicosídeo cianogênico linamarina. No organismo, o cianeto bloqueia a cadeia de transporte de elétrons inibindo a respiração celular e, provocando, entre outras coisas, a produção de radicais livres que podem agir no DNA, através da formação de adutos exocíclicos. O objetivo deste trabalho foi a avaliação da atividade citotóxica, genotóxica e mutagênica de folhas e tucupi, crus e cozidos, de mandioca mansa e brava, usando os ensaios do MTT, cometa e citoma em células HepG2. Os resultados obtidos demonstraram que a viabilidade celular decai à medida que a concentração aumenta na maioria dos grupos de tratamento. No ensaio do cometa, a análise visual demonstrou que o cianeto de potássio, usado como padrão, foi genotóxico em todas as concentrações testadas (5,0; 15,0 e 25,0 ?g/mL). As amostras de folhas de mandioca brava foram genotóxicas somente nas concentrações 15,0 e 25,0 ?g/mL (cruas) e 5,0; 15,0 e 25,0 ?g/mL (cozidas). As amostras de mandioca mansa foram genotóxicas apenas quando cozidas (5,0 e 25,0 ?g/mL). Já as amostras de tucupi, tanto cruas quanto cozidas, demonstraram dano ao DNA de células HepG2 em todas as concentrações testadas (20,0; 40,0 e 60.0 ?g/mL). Utilizando análise de fragmentação de DNA observamos que o cianeto de potássio foi genotóxico apenas na avaliação da porcentagem de DNA na cauda. Já amostras de mandioca brava e mansa, de maneira geral, demonstraram valores de porcentagem de DNA na cauda, tail moment e olive moment maiores em relação ao grupo controle negativo, mas, somente as folhas de mandioca, em algumas concentrações, demonstraram valores estatisticamente significativos. Observando o ensaio do citoma, as concentrações de folhas e tucupi, crus e cozidos, tanto de mandioca brava quanto de mandioca mansa mostraram um discreto aumento no número de micronúcleos em células HepG2 binucleadas, estatisticamente não significativo, em relação ao grupo controle negativo. Já o número de pontes nucleoplasmáticas e brotos nucleares foi menor que no grupo controle. Os danos aqui observados pelo ensaio do cometa podem estar transitoriamente presentes ii como intermediários formados durante o reparo de lesões no DNA. A ausência de brotos nucleares, pontes nucleoplasmáticas e resultados estatísticos significativos em relação ao grupo controle negativo, não nos permitem afirmar presença de mutagenicidade em células HepG2 tratadas com mandioca tanto brava quanto mansa. De maneira geral, o cozimento das amostras não foi um fator determinante na diminuição do dano observado em células HepG2. Nossos resultados confirmam apenas citotoxicidade e genotoxicidade das variedades da mandioca nas concentrações e sistema celular utilizados. Os mecanismos moleculares que envolvem a genotoxicidade da mandioca requerem estudos futuros. Para o consumo da mandioca devem ser levados em consideração tipo de processamento realizado para extração de compostos cianogênicos, níveis de glicosídeos cianogênicos nos produtos consumidos, quantidade de mandioca consumida e estado nutricional do consumidor
The food factor can be considered a tumor causing agent reponsasible for the etiology of gastric cancer in the state of Pará Cassava ( Manihot esculenta Crants is one of the many food species of the Amazon indiscriminately consumed by the inhabitants of the northern region Cyanide, its main toxic component, can be released during cassava processing through the hydrolysis of the cyanogenic glycoside linamarin. In the body, cyanide blocks the electron transport chain by inhibiting cell respiration which brings about, among other things, the production of free radicals which can act upon DNA through the formation of exocyclical adducts. The main goal of this study was the assessment of the citotoxic, genotoxic and mutagenic role of the leaves and tucupi juice of wild and sweet cassava, both raw and cooked, using the MTT, comet and cytome assays in HepG2 cells. The results gathered have shown that cell viability decreases as the concentration increases in most treatment groups. In the comet assay, a visual analysis has shown that potassium cyanide, used as a standard, was genotoxic in all concentrations tested (5.0, 15.0 and 25.0 ?g/mL). Samples of wild cassava leaves were genotoxic only in concentrations of 15.0 and 25.0 ?g/mL for raw leaves, and 5.0, 15.0 and 25.0 ?g/mL for cooked leaves. Samples of sweet cassava leaves were genotoxic only when cooked (5.0 and 25.0 ?g/mL). Yet, samples of tucupi juice, both raw and cooked, have shown damage to DNA in HepG2 cells at all concentrations tested (20.0, 40.0 and 60.0 ?g/mL). In performing DNA fragmentation analysis, it was observed that potassium cyanide was genotoxic only in the assessment of percentage DNA in tail. Whereas the wild and sweet cassava samples, in a general fashion, have shown greater values of percentage DNA in tail, tail moment and olive moment than the negative control group, but only the cassava leaves revealed statistically significant values, in some concentrations. For the cytome assay, concentrations of leaves and of tucupi juice, raw and cooked, of both wild and sweet cassava, have shown a slight increase in the number of micronuclei in binucleated HepG2 cells, not statistically significant as compared to the negative control group. On the other hand, the number of nucleoplasmic bridges and nuclear buds in binucleated cells was lower than the value found in the negative control group. The damages verified herein by the comet assay may be transiently present as intermediates formed during repair of DNA lesions. The absence of iv nucleoplasmic bridges, nuclear buds and of statistically significant results vis-à-vis the negative control group do not warrant the assertion for the presence of mutagenicity in HepG2 cells treated with either wild or sweet cassava. In general, the cooking of the samples was not determining factor of the decrease in damage observed in HepG2 cells. Our results only confirm cytotoxicity and genotoxicity of wild and sweet cassava species in the concentrations and cell system used. The molecular mechanisms involving genotoxicity of cassava require further studies. For the consumption of cassava, the way of processing performed for extracting cyanogen contents, the levels of cyanogenic glycosides in the products consumed, amount of cassava consumed as well as the nutritional condition of the consumer must be taken into account.

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Lamy, Evelyn [Verfasser]. "MTBITC-induced apoptosis and cell cycle arrest of human hepatoma (HepG2) cells : a link between p53 and human telomerase? / Evelyn Lamy". Gießen : Universitätsbibliothek, 2015. http://d-nb.info/1068922540/34.

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Dorta, Daniel Junqueira. "Efeitos citoprotetor e/ou citotóxico dos flavonóides: estudo estrutura-atividade envolvendo mecanismos mitocondriais, com ênfase na apoptose". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/60/60134/tde-17102007-160656/.

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Realizou-se um estudo estrutura-atividade sobre os efeitos citoprotetor/citotóxico de 5 flavonóides envolvendo processos mitocondriais, com ênfase na apoptose. Nossos resultados mostram que a dupla ligação na posição 2-3 / grupos 3-OH em conjugação com a função 4-oxo no anel C da estrutura dos flavonóides parece favorecer a interação destes compostos com a membrana mitocondrial, diminuindo a sua fluidez, e tanto inibindo a cadeia respiratória das mitocôndrias, quanto causando desacoplamento. Por outro lado, a estrutura o-di-OH no anel B parece favorecer a inibição da cadeia respiratória, sendo que a ausência desta estrutura parece favorecer a atividade desacopladora. Os flavonóides que não afetaram a respiração mitocondrial, induziram a transição de permeabilidade mitocondrial. A capacidade dos flavonóides em liberar o Ca2+ acumulado pelas mitocôndrias correlaciona-se com a sua capacidade de afetar a respiração mitocondrial e sua inabilidade em induzir a transição de permeabilidade mitocondrial. Já os dados referentes aos estudos da atividade protetora contra a formação de radicais livres demonstraram que a quercetina, luteolina e a galangina foram substancialmente mais potentes que a taxifolina e a catequina em conferir proteção contra a lipoperoxidação, embora somente a quercetina tenha sido um efetivo seqüestrador tanto de DPPH?, quanto de O2?-. Esses resultados sugerem que a dupla ligação na posição 2-3 em conjugação com a função 4-oxo na estrutura dos flavonóides são os fatores mais importantes na atividade antioxidante dos flavonóides sobre as mitocôndrias. Ainda, a presença da estrutura o-di-OH no anel B, conforme observado na quercetina, favorece essa atividade via seqüestro de O2?-, enquanto que a ausência dessa característica estrutural na galangina, a favorece via diminuição da fluidez de membrana e/ou desacoplamento mitocondrial. Os ensaios realizados para avaliar o efeito dos flavonóides sobre as células HepG2 mostraram que galangina, luteolina e quercetina são capazes de induzir morte celular. Esse efeito parece estar associado à dissipação do potencial de membrana mitocondrial e à diminuição na capacidade energética celular, mais pronunciada no caso dos dois primeiros; porém, como essa diminuição na concentração de ATP não é drástica, a morte celular pode ocorrer por apoptose. Os experimentos realizados para avaliar essa possibilidade sugerem uma ativação das caspases via mitocôndria, observada pelo aumento das atividades de caspase -9 e -3 e também pela exposição de fosfatidil serina. A taxifolina que não apresentou capacidade de produzir dano celular, apresentou, por outro lado, capacidade de prevenir parcialmente a diminuição de viabilidade das células HepG2 induzida pelo pró-oxidante t-butilhidroperóxido, aparentemente por meio de sua atividade antioxidante que inibiu, também de forma parcial, o acúmulo de espécies reativas de oxigênio.
We carried out a structure-activity study addressing the protective/toxic effects of 5 flavonoids (quercetin, taxifolin, luteolin, catechin and galangin) upon mitochondrial aspects with emphasis on the mechanisms potentially involved in cell apoptosis. The major findings were: The 2,3 double bond/3-OH group in conjugation with the 4-oxo function on the C-ring in the flavonoid structure seems favour the interaction of these compounds with the mitochondrial membrane, decreasing its fluidity either inhibiting the respiratory chain of mitochondria or causing uncoupling; while the o-di-OH on the B-ring seems favour the respiratory chain inhibition, the absence of this structure seems favour the uncoupling activity. The flavonoids not affecting the respiration of mitochondria induced MPT. The ability of flavonoids to induce the release of mitochondria-accumulated Ca2+ correlated well with their ability to affect mitochondrial respiration on the one hand, and their inability to induce MPT, on the other. The data concerning the protective activity against the free radical formation showed that quercetin, luteolin and galangin were far more potent than taxifolin and catechin in affording protection against lipid peroxidation, although only quercetin was an effective scavenger of both DPPH? and O2?-. These results suggest that the 2,3-double bound in conjugation with the 4-oxo function in the flavonoid structure are major determinants of the antioxidant activity of flavonoids on mitochondria, the presence of an o-di-OH structure on the B-ring, as occurring in quercetin, favouring this activity via O2?- scavenging, while the absence of this structural feature in galangin, favouring it via decrease in membrane fluidity and/or mitochondrial uncoupling. The assays addressing the flavonoids effects on HepG2 cells showed that galangin, luteolin and quercetin are able to induce cell death. This effect appears to be linked to the mitochondrial membrane potential dissipation and consequent decrease in the cellular energy charge, more pronounced for the galangin or luteolin treatment. However, since this decrease in ATP content is not drastic, the apoptosis process can occur. The set of experiments performed in order to evaluate this possibility demonstrated caspases-9 and -3 activation and also phosphatidylserine exposure on the cell membrane. On the other hand, taxifolin, that did not present ability to induce injury to the cell, was able to partially inhibit a viability decrease of HepG2 cell exposed to the pro-oxidant t-butylhydroperoxide, probably on account of its capacity to partially decrease ROS formation.

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Chen, Wen Xin, i 陳文馨. "Cell death pathway in HepG2 cells infected with Klebsiella pneumoniae". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/74869141036163957800.

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碩士
長庚大學
基礎醫學研究所
96
Severe liver abscess caused by Klebsiella pneumoniae (KP) has been observed recently in Taiwan, mostly in diabetic patients and through nosocomial infections. How the bacteria cause liver abscess is not clear. The aim of this study was to investigate the mechanism of cell death in KP-infected hepatocytes. Using a human hepatoma cell line, HepG2, as a model system, we studied the cell death pathway involved in HepG2 infected with liver abscess-causing KP (KP5). The cytotoxic effect of KP5 infected-HepG2 cells is time-and dose-dependent. KP5 induced cell cycle arrest at the G1 phase and prominent accumulation of sub-G1 fraction 16 hr after the infection. The infected cells also showed DNA laddering and little chromatin condensation. It seems that KP5 caused an induction of caspase 3 activity, according to the appearance of the caspase 3 fragments early after the infection and stimulated proteolytic cleavage of PARP within 2-8 hr. Annexin V-FITC/PI staining assay indicated that secondary necrosis appeared at early infection phase, followed by a significant increase in the percentage of primary necrotic cells at 9 hr. The protein expression of Bax/Bcl-2 ratio was not up-regulated and the level of Bcl-2 and Bcl-xL was down-regulated after infection. In conclusion, the study suggested that KP5 induced cell cycle arrest at the G1 phase and secondary necrosis of HepG2 cells through apoptotic pathway at the early infection phase. At the late infection phase, KP5 induced cell death through down-regulation of Bcl-2 and Bcl-xL protein, prominent primary necrosis, and caspase-independent DNA fragmentation.

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19

Wu, Yifei. "The effect of saturated and unsaturated fatty acids on HEPG2 cells and the trehalose protection of HEPG2 cells on palmitate induced toxicity". Diss., 2008.

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Thesis (M.S.)--Michigan State University. Dept. of Chemical Engineering and Material Science, 2008.
Title from PDF t.p. (viewed on July 29, 2009) Includes bibliographical references (p. 34-41). Also issued in print.

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20

Yang, Li-chia, i 楊禮嘉. "Electrophoresis of HepG2 Cells: Experimental and Theoretical Modeling". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/45539161524917820069.

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碩士
國立臺灣大學
化學工程學研究所
93
Electrophoresis, the movement of a charged entity as a response to an applied electric field, is a useful tool to gather information about the charged conditions on cell surface. The electrophoretic behavior of HepG2 cells is investigated in this study both experimentally and theoretically. Experimentally, Zetasizer3000 is used to determine the mobility of HepG2 cells. Effects of pH, ionic strength, and different kinds of divalent cations are examined. We can discuss the properties and the kinds of functional groups on the surface of HepG2 cells by electrophoresis. The result shows that absolute mobility increases with increasing pH, and decreases with increasing ionic strength. Because of different binding constants with surface functional group, there is different mobility with different kinds of divalent cation. Under pH 4.3, the mobility of HepG2 cells reverses to positive sign, and we can therefore infer that there are at least one kind of acid functional group and one kind of base functional group on the surface of HepG2 cells. There are two parts in the theoretical modeling. The first one the ion size in the electrolyte is ignored, and in the second it is considered. A charge-regulated model is proposed to simulate the charged conditions on cell surface, and to estimate the key parameters such as the thickness of the membrane layer, the density, the dissociation constant of dissociable functional groups in the membrane layer, and the binding constant of divalent cation. FlexPDE software is used to solve the governing equations. These data are compared to the experimental data in order to estimate the suitable parameters. The results can be used to explain the electrophoresis behavior of HepG2 cells.

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21

Hua, Yi Syuan, i 滑翌軒. "G6PD Knockdown Enhances Inflammatory Responses in HepG2 cells". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/98949725840134162851.

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碩士
長庚大學
醫學生物技術暨檢驗學系
98
Glucos-6-phosphate dehydrogenase (G6PD) plays an important role in the generation of NADPH and maintains cellular redox homeostasis. Imbalanced redox status alters cellular physiology including cell proliferation, differentiation and inflammatory response. Since G6PD deficiency affects the innate cellular immune response and accelerates cellular senescence, we attempt to further elucidate the relationship between G6PD and inflammatory response. In this study, G6PD-scramble (Sc) and G6PD-knockdown (Gi) HepG2 cells were used as cellular model to determine the role of G6PD in inflammation. Gi cells displayed lower G6PD activity (10% of Sc) and lower G6PD protein expression (20% of Sc). Elevated reactive oxygen species (ROS) production was detected in Gi cells (140 % of Sc). Gi cells displayed higher inflammatory cytokine. At the basal level, IL-8 gene expression and protein secretion were significantly increased in Gi cells compared to Sc cells (3 folds). Palmitate overload as an additional stress enhanced IL-8 gene expression (5 folds) and protein secretion (2 folds) without significant ROS increase. IL-8 secretion at the basal level and under lipid stress was inhibited by NF-κB inhibitor and JNK inhibitor. These data indicated that G6PD deficiency could enhance cellular pro-inflammatory response through activation of NF-κB pathway and JNK activation. Moreover, lipotoxicity can exacerbate pro-inflammatory response in G6PD-deficient cells.

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22

Yang, Ya-Han, i 楊雅涵. "Generation of liver cancer stem cell-like cells from HepG2 derived induced pluripotent stem cell-like cells". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/m6vnb5.

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碩士
高雄醫學大學
醫學研究所碩士班
103
Recently, liver cancer (hepatocellular carcinoma) is the second most common malignant tumor among the top ten cancer death in Taiwan. Nevertheless, only about one to five patients could successfully undergo tumor removal by surgery and show good prognosis. In addition, the recurrence rate of liver cancer is high. Nowadays, recurrence is considered highly correlated with cancer stem cells (CSCs). At 2006, Professor Shinya Yamanaka found mouse adult fibroblast can be transfected by lentivirus with OCT4, SOX2, KLF4, C-MYC, and shTP53 and reprogramed into induced pluripotent stem cells (iPSCs). iPSCs have a remarkable potential for cell replacement therapies. However, after reprogramming, whether the cells would form into normal or cancer stem cells still require clarifications. Here, we acquired HepG2-derived induced pluripotent stem cell-like cells (HepG2-iPS-like cells), by transduce the above four factors into HepG2 cells. Then, the cancerous mass of SCID mice derived from one colony was dissected, and cultured to establish reprogrammed HepG2-derived CSC-like cells (designated rG2-DC-1C). rG2-DC-1C showed continuous expression of stemness genes, such as OCT4, and present higher invasion ability, chemoresistance, and low-serum survival rate. Moreover, the expressions of the OCT4 and c-JUN were significantly increased. We also found shutdown the expression of OCT4 in rG2-DC-1C resulted in decrease the tumor formation ability. Finally, the high expression of c-JUN and OCT4 were detected and correlated significantly in human HCC specimens. Taken together, OCT4 and c-JUN are the possible candidates for cancer initiation in transition from patient-specific iPSCs to CSCs. In the future, OCT4 and c-JUN could be a new target of therapy for liver cancer.

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23

Wang, Huei-Rong, i 王惠蓉. "Effects of plant components on human hepatoma cell line HepG2 cells and vascular smooth muscle cells". Thesis, 1994. http://ndltd.ncl.edu.tw/handle/73339534542527555515.

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碩士
國立臺灣大學
藥理學研究所
82
1.肝細胞增生( proliferation ) 是造成肝細胞癌( hepatocellular carcinoma ) 的主要原因之一。藥物作用4.5 小時，baicalein與 esculetin 皆可抑制 HepG2 細胞增生，且其作用程度類似。藥物作用 24 小時，以 baicalein 抑制效果最強， d-catechin 次之， esculetin 最弱o 在 HepG2 細胞，baicalein 之抗增生作用可能主要經由抑制 protein tyrosine kinase ; esculetin 的作用機轉可能是抑制 protein tyrosine kinase、protein kinase C，及促進 PGE2的合成。 2.血管平滑肌細胞的增生 (proliferation) 是造成粥狀動脈硬化 (atherosclerosis) 的主要原因之一。實驗首先比較九個 coumarins 藥物對血管平滑肌細胞增生的作用，結果以 esculetin 效果最強，於10-4 M可100 % 抑制增生。血管平滑肌細胞受胎牛血清 (fetal calf serum)刺激後，開始進入 cell cycle。由 cell cycle 來分析，esculetin可能作用於此兩類 growth factors 的共同 mitogenic pathway。本論文證實 esculetin 對平滑肌細胞的抗增生作用機轉，可能主要抑制 protein tyrosine kinase。 1.The effects of plant components on the proliferation response of cultured human hepatoma cell line (HepG2 cells) were studied. The possible action mechanisms of baicalein were studied and compared with those of esculetin. After treatment for 24 hr, baicalein exhibited greater antiproliferative activity than esculetin. Our results showed that the antiproliferative effect of baicalein on HepG2 cells may be mainly mediated through inhibition of protein tyrosine kinase; while esculetin may act by inhibition of protein tyrosine kinase, protein kinase C and increasing the release of PGE2. 2.The effects of plant components on the proliferation response of cultured rabbit vascular smooth muscle cells were studied. After stimulation with fetal calf serum, quiescent vascular smooth muscle cells entered cell cycle. Esculetin suppresses serum-stimulated DNA synthesis at G1 phase, G1/S transition and S phase of the cell cycle. Therefore, esculetin may alter the transduction signals involved in cell proliferation. Our results suggest that the antiproliferative effect of esculetin on vascular smooth muscle cells may be mediated mainly through inhibition of protein tyrosine kinase.

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24

chuen, Sung jia, i 宋佳純. "Benzidine Induces DNA Damage Signaling Pathways in HepG2 cells". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/59816481071738841330.

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碩士
高雄師範大學
生物科技系
98
Benzidine, a known human carcinogen, induces DNA damage in human hepatoma G2 cells (HepG2 cells) via the analysis of comet assay. A DNA damage signaling pathway of benzidine-induced DNA damage was determined. A PCR array composing of 84 genes belonging to three groups of DNA repair, cell cycle arrest, and apoptosis were tested for the differential genes in HepG2 cells treated with vs without 200μM benzidine after 24h incubation. Results showed that 24 genes expression levels were unregulated over 2 fold (p<0.05) in 200µM benzidine- treated cells. These genes are categorized according to their functions: DNA damage sensors, DNA double strand break repair, base excision repair, nucleotide excision repair, mismatch repair, cell cycle arrest and apoptosis. The results were consistent with quantitative real-time PCR. Among these differential genes, three DNA repair genes, ERCC1, PCNA, and MUTYH corresponded with their proteins expression using Western blot. Following the results of flow cytometry, we found that benzidine causes G2/M arrest and induces apoptosis in HepG2 cells. Collectively, the DNA damage signaling pathways in benzidine-treated cells consist of DNA repair, cell cycle arrest, and apoptosis.

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Hwang, Yu-Chun, i 黃宇君. "Squamocin causes cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/50804116840024360384.

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碩士
高雄醫學大學
天然藥物研究所
97
Malignant neoplasm has become the leading cause of death in Taiwan. According to stastistic data from Department of Health, hepatocellular carcinoma (HCC) is the second common cancer in Taiwan. At present, systemic therapies including chemotherapy and molecular targeted therapy can not effectively treat this malignancy because of resistance to drugs and descent of tolerance caused by liver dysfunction. Therefore, it is an emergent task to find new drug candidates for treating HCC. Natural products represent a rich source of new chemical compounds for developing anticancer drugs. In previous studies, squamocin, an Annonaceous acetogenin, has been reported as a potential anticancer agent. In the present study, we found that squamocin inhibited the growth of HepG2 cells at very low concentrations (0.5~5nM). Flow cytometry showed that squamocin induced cell cycle arrest at G1 and G2/M phase in HepG2 cells. Western blotting revealed that squamocin decreased the expression of cyclin D, Cdk2 and Cdk4. Besides, squamocin treatment also led to an increase in hypophosphorylated pRB and a decrease in E2F1 protein levels. In G2 phase-related proteins, squamoicin decrease Cdk1 and Cdc25C and induced Cdc25C Ser216 phosphorylation. To analysis the upstream regulators of Cdc25C, we observed the activation of Chk1, Chk2, and p38 after treatment of HepG2 cells with squamocin. The results suggested Chk1, Chk2 and p38 might be responsible for squamocin-induced Cdc25C downregulation and thus led to cell cycle arrest in G2/M phase. In addition, prolonged treatment (48h) of HepG2 cells with a high concentration of squamocin (5nM) induced apoptotic death. However, squamocin did not activate caspase cascade, suggesting that squamocin-induced apoptosis is caspase-independent. In conclusion, based on its very potent and novel activity, squamocin can be considered as a promising anticancer drug, and it is worthy to find the special target of squamocin in HepG2 cells.

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26

Shan, Han-i., i 孫菡儀. "Molecular mechanism of human hepatoma cell line HepG2 cells growth arrest by esculetin". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/81460098403338068236.

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碩士
中山醫學院
生物化學研究所
89
Abstract Esculetin is a phenolic compound of coumarin derivative containing in many plants such as Atemisiae capillaris Flos ( Compositae ), leaves of Citrus limonia ( Rutaceae ), Digitalis purpurea L. ( Scropulariaceae ), Euphorbia lathyris L. ( Eupho-biaceae ), Atropa belladonna ( Solanaceae ), Datura Stramonium L., Hyoscyamus niger L. In the past decade esculetin has been reported to have antiplatelet, antioxdant, anti-inflammatory and anticarcinogenic effects. Recently, it has also been reported to decrease the survival of human leukemia and breast cancer cells. However, the antiproliferation mechanism of esculetin on cancer is not well understood. In this study, the preliminary assay showed that esculetin inhibited the proliferation of human HepG2 hepatoma cells. By flowcytometric assay, it demostrated that esculetin inhibited the cell cycle progression of HepG2 hepatoma cells. In addition, we examined the expression of cell cycle-related proteins including cyclins, cdks, and CKIs. It showed that (1) esculetin delayed Rb phosphorylation compared with control group in HepG2, （2） attenuating the interaction of E2F1/DP-1 and c-Myc/Max. （3） Esculetin also decreased of cyclin E, CDC25A, and increased expression of p16, p53, p21, p27 significantly in HepG2 cells. Furthermore, （4）esculetin blocked the Ras/MAPK, p38 and Akt signal transduction resulting of cell growth arrest or apoptosis. Take together, esculetin presented antiproliferation effect involving modulating the expression of cell cycle related proteins and the MAPK signal pathway.

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27

Tuan, Yen-Fan, i 段姸帆. "3,3’- Dichlorobenzidine-induced cytotoxicity via MAPK pathways in HepG2 cells". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/58496877698433205043.

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碩士
國立高雄師範大學
生物科學研究所
100
Epidemiological studies have suggested a relationship between long term exposure of 3,3'-Dichlorobenzidine (DCB) among dyeing industry workers and the increased risks of cancer development, especially bladder cancer and lymphohematopoietic cancer. Our previous study had demonstrated that DCB leaded to genotoxicity by causing DNA breakage in human lymphocytes. In this study, the signaling pathways involved in DCB-induced DNA damage and cytotoxicity in human liver cancer cells (HepG2) were investigated. We found that DCB could increase the expression of-H2AX, a sensitive molecular marker of DNA double-strand breaks, in a dose-dependent manner, and reach a maximum effect at 10 M. These results indicate that DCB could induce DNA double-strand breakage in HepG2 cells. The result of MTT assay shows that DCB inhibit 20~40 % HepG2 cell viability in a concentration ranges of 25~100 M. The cell cycle analysis revealed that DCB induced G2/M phase arrest and sub-G1 phase accumulation in HepG2 cells exposed to DCB for 24 h. In addition, Bcl-2/Bax ratio and mitochondrial membrane potential were decreased in cells treated with DCB. The activities of caspase-3 and caspase-9 were also enhanced by DCB treatment in a dose-dependent manner. These results indicated that DCB could induce HepG2 cell apoptosis through a mitochondria/caspases pathway. To determine the signaling pathways of DCB-induced cytotoxicity in HepG2 cells, we found that DCB significantly increased the phosphorylation level of JNK and ERK but not p38 in a time- and dose-dependent manner. To further determine whether ERK and JNK activation were required in the DCB-induced caspase-3 activity and cell mortality, two pharmacological inhibitors, SP600125 (JNK inhibitor) and U0126 (ERK inhibitor), were used. We found that JNK inhibitor but not ERK inhibitor could attenuate DCB-induced caspase-3 activity and cell mortality. Furthermore, we used proteomic analysis tool to investigate whether there are another pathways participated in DCB–induced DNA damage and cytotoxicity in HepG2 cells. We found 42 proteins were up-regulated and 3 proteins were down-regulated (more or less than two fold, p<0.05) in HepG2 cells treated with 100 M of DCB for 24 h. Twenty protein spots were identified by liquid chromatograph/tandem mass spectrometer (LC/MS/MS) . These known proteins included those functions in diverse biological processes such as anti-apoptosis, endoplasmic reticulum stress, DNA repair were identified. The expression levels of four proteins, 14-3-3 protein theta, CGI-46 protein, proteasome subunit Y and heat shock 70 kDa protein 4, were verified by Western blot analysis. In conclusion, our results show that DCB could induce cell apoptosis in HepG2 cells via MAPK (JNK) and mitochondria/caspases pathways. The regulation of other proteins such as cell anti-apoptosis, DNA repair and endoplasmic reticulum stress-related proteins may also involve in DCB–induced DNA damage and cytotoxicity in HepG2 cells.

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Chan, Yu-Ju, i 詹育儒. "Curcuma Oil Induces a ROS-Dependent Apoptotic Cell Death in Human Hepatoma HepG2 Cells". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/73182723709217910645.

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碩士
國立暨南國際大學
生物醫學科技研究所
97
The hepatocellular carcinoma (HCC) has high prevalence rates in the world, especially in Asia. Recently, it is the leading cause of death in Taiwan. Currently, no effective therapy is available for the treatment of HCC patients. Thus, it is crucially important to develop effectively therapeutic strategies for the management of HCC. Curcuma longa L., which belongs to the Zingiberaceae family, has been used as a folk medicine in South-Eastern Asia. The main constituents of Curcuma longa L. are curcuma oil and curcumin. Curcumin has been reported as a potential drug to cure liver diseases. However, there are limited references in the biological effects of curcuma oil on liver diseases. To examine the effect of curcuma oil on liver cancer cells, human hepatocellular carcinoma HepG2 cells were treated with various concentrations of curcuma oil for indicated time periods. Data from cell viability determination, morphological investigation, and TUNEL assay indicated that curcuma oil induced apoptotic cell death in HepG2 cells. Moreover, curcuma oil increased caspase-3、 -8 and -9 activities in a dose- and time-dependent manner. Additionally, curcuma oil treatment elicited an early and rapidly production of reactive oxygen species (ROS). Treatment with antioxidants , N-acetyl-cysteine（NAC）and ascorbic acod, significantly blocked curcuma oil-induced apoptosis. Furthermore, curcuma oil increased the expression levels of phosphorylated ERK 、phosphorylated JNK、p73 and Bax while decreased the levels of p53 、phosphorylated p53ser 15 and Bcl-2 . These results suggest that curcuma oil might induce a ROS-dependent apoptotic cell death in HepG2 cells.

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29

Ho, Pei-Tzu, i 何珮慈. "Cell growth inhibitory effects of pterostilbene and 3′- hydroxypterostilbene in human hepatoma HepG2 cells". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8epwxp.

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30

PENG, YA-JYUN, i 彭雅君. "Investigation of Huanglian (Rhizoma Coptidis) extract Induced Cell Apoptosis in Human Hepatoblastoma HepG2 Cells". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/nqhx58.

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碩士
輔英科技大學
生物科技系碩士班
107
Huanglian (Rhizoma coptidis), a widely used traditional Chinese medicine relatively safe with no adverse effects from long term use, has been used for the treatment of heat-clearing and detoxifying. Berberine and Palmatine, the yellow isoquinoline alkaloid extracted from Huanglian, have a wide range of biological and pharmacological activities that include inhibition of DNA, anti-proliferative and protein synthesis, arrest of cell cycle progression and pro-apoptotic effects on cancer cells. In the study we investigated the cytotoxic effects of Beberine and Palmatine, two components of Huanglian in Human Hepatoblastoma HepG2 Cells, and investigated the possible mechanism of their anticancer activities. It has previously studies shown that the expression of several ATP-binding cassette (ABC) transporters confer multidrug resistance are implicated in the sensitivity towards medicine in cancer cells. In the study, different P-glycoprotein inhibitors, Verapamil and Amiodarone and were used in the present of Huanglian extract to treat Human Hepatoblastoma HepG2 Cells. Cotreated cells with the P-glycoprotein inhibitor and Huanglian extract results in rapid inhibition of cell growth and the apoptotic cells become more abundant. The results showed that the anti- P-glycoprotein multidrug resistance drugs Verapamil and Amiodarone could increase the cytotoxicity of Beberine and Palmatine in Human Hepatoblastoma HepG2 cells. We investigated the MAPK signaling pathway and free radicals by using free radical scavenger N-acetylcysteine(NAC) and Atorvastatin in Huanglian (Rhizoma Coptidis) extracts induced cytotoxicity of HepG2 cells. Our data showed that in the presence of NAC was not able to block cytotoxity induced by Huanglian (Rhizoma Coptidis) extract in HepG2 cells. Our data suggested that the decreased of oxidative stress by NAC could not abort the cytotoxity induced by Huanglian (Rhizoma Coptidis) extracts. In addition, Our data showed that the administration of Atorvastatin per se had no significant effect on viability in HepG2 cells, while cotreated the cells with Atorvastatin and Huanglian extract result in cell growth inhibition and increased cell apoptosis. Our data suggested that Atorvastatin may involve in Huanglian (Rhizoma Coptidis) extracts induced cytotoxicity of HepG2 cells via MAPK pathway.

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31

"Effect of antisense oligonucleotide against glucose transporter on human hepatocellular carcinoma HepG2 and its multi-drug resistant R-HepG2 cells". 2001. http://library.cuhk.edu.hk/record=b5890822.

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Lam Mei Wah.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 172-181).
Abstracts in English and Chinese.
Abstract --- p.i
論文撮要 --- p.iv
Acknowledgement --- p.vii
Table of contents --- p.viii
List of tables --- p.xi
List of figures --- p.xii
Abbreviations --- p.xvii
Chapter Chapter 1: --- Introduction --- p.1
Chapter 1.1 --- The facilitative glucose transporter family --- p.2
Chapter 1.2 --- Overexpression of glucose transporters in tumor cells --- p.5
Chapter 1.3 --- Antisense strategy --- p.8
Chapter 1.3.1 --- Modifications of oligonucleotides --- p.9
Chapter 1.3.2 --- Delivery system for oligonucleotides --- p.13
Chapter 1.3.3 --- Factors influencing antisense activity --- p.16
Chapter 1.3.4 --- Mechanism of action of antisense oligonucleotides --- p.17
Chapter 1.3.5 --- Clinical trials of antisense treatment --- p.21
Chapter 1.4 --- Objective of present study --- p.23
Chapter Chapter 2: --- Materials and Methods --- p.24
Chapter 2.1 --- Materials --- p.25
Chapter 2.1.1 --- Reagents and buffers --- p.25
Chapter 2.1.2 --- Reagents for Western blot analysis --- p.26
Chapter 2.1.3 --- Culture medium --- p.28
Chapter 2.1.4 --- Chemicals --- p.29
Chapter 2.1.5 --- Culture of cells --- p.31
Chapter 2.1.5.1 --- Differentiated Human Hepatoblastoma cell line (HepG2) --- p.31
Chapter 2.1.5.2 --- "Multi-drug resistant hepatoma cell line, R-HepG2 cells" --- p.32
Chapter 2.1.6 --- Animal Studies --- p.33
Chapter 2.2 --- Methods --- p.34
Chapter 2.2.1 --- In vitro studies --- p.34
Chapter 2.2.1.1 --- Design of oligonucleotide sequence --- p.34
Chapter 2.2.1.2 --- Transfection --- p.35
Chapter 2.2.1.3 --- MTT assay --- p.36
Chapter 2.2.1.4 --- Flow cytometry --- p.37
Chapter 2.2.1.5 --- H-thymidine incorporation assay --- p.45
Chapter 2.2.1.6 --- 2-Deoxy-D-[l-3H] glucose uptake assay --- p.46
Chapter 2.2.1.7 --- Adenosine-5'-triphosphate (ATP) assay --- p.47
Chapter 2.2.1.8 --- Western blot analysis --- p.50
Chapter 2.2.2 --- In vivo studies --- p.55
Chapter 2.2.2.1 --- Animal studies --- p.55
Chapter (i) --- Lactate dehydrogenase (LDH) assay --- p.58
Chapter (ii) --- Creatine kinase (CK) assay --- p.60
Chapter (iii) --- Aspartate transaminase (AST) assay --- p.62
Chapter (iv) --- Alanine transaminase (ALT) assay --- p.64
Chapter Chapter 3: --- Results --- p.67
Chapter 3.1 --- In vitro studies --- p.68
Chapter 3.1.1 --- Characteristics of the multi-drug resistant cell line (R-HepG2) developed in our laboratory --- p.68
Chapter 3.1.2 --- Effect of lipofectin on cell viability --- p.77
Chapter 3.1.3 --- Cellular uptake of antisense oligonucleotide --- p.82
Chapter 3.1.4 --- Effect of Glut 2 antisense oligonucleotides on human hepatoma HepG2 and its multidrug resistant (R-HepG2) cells by MTT assay --- p.87
Chapter 3.1.5 --- Suppression of Glut 2 protein expression by antisense oligonucleotides as revealed by Western blot analysis --- p.96
Chapter 3.1.6 --- Uptake of glucose in HepG2 and R-HepG2 after Glut 2 antisense treatment --- p.100
Chapter 3.1.7 --- ATP content in HepG2 and R-HepG2 was lowered after treating the cells with antisense oligonucleotides --- p.108
Chapter 3.1.8 --- Antisense oligonucleotides against Glut 2 exhibited antiproliferative effect on HepG2 and R-HepG2 cells --- p.117
Chapter 3.1.9 --- Change in cell cycle pattern after antisense treatment --- p.125
Chapter 3.1.10 --- Glut 2 antisense oligonucleotides did not induce apoptosis --- p.131
Chapter 3.2 --- In vivo studies --- p.135
Chapter 3.2.1 --- Effect of antisense oligonucleotides on the tumor weight in nude mice bearing HepG2 cells or R-HepG2 cells --- p.135
Chapter 3.2.2 --- Assessment of any side effect of antisense drug done on normal tissues of nude mice --- p.139
Chapter 3.2.2.1 --- Treatment on tumor bearing nude mice with Glut 2 antisense or sense oligonucleotides did not cause myocardial injury --- p.139
Chapter 3.2.2.2 --- Liver injury was not detected in Glut 2 antisense or sense oligonucleotides treated tumor bearing nude mice --- p.147
Chapter Chapter 4: --- Discussion --- p.151
Chapter 4.1 --- In vitro study of the effect of antisense oligonucleotides against Glut 2 on HepG2 and its multi-drug resistant R-HepG2 cell lines --- p.152
Chapter 4.1.1 --- Design of antisense oligonucleotides against Glut 2 --- p.154
Chapter 4.1.2 --- Conditions for antisense inhibition by oligonucleotides --- p.155
Chapter 4.1.3 --- Biological effects of antisense oligonucleotides --- p.158
Chapter 4.2 --- In vivo study of the effect of antisense oligonucleotides against Glut 2 on HepG2 or R-HepG2 cells bearing nude mice --- p.166
Chapter 4.2.1 --- Effect of Glut 2 antisense oligonucleotides on tumor weight --- p.167
Chapter 4.2.2 --- In vivo side effects of oligonucleotides --- p.168
Chapter 4.3 --- Conclusion --- p.169
Bibliography --- p.172

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32

"Roles of mitochondria in the multidrug resistance in R-HepG2 cells". 2002. http://library.cuhk.edu.hk/record=b6073488.

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by Li Yanchun.
"August 2000."
Thesis (Ph.D.)--Chinese University of Hong Kong, 2002.
Includes bibliographical references (p. 193-213).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.

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33

"Inducibility and overexpression studies of antiquitin in HEK293 and HepG2 cells". 2005. http://library.cuhk.edu.hk/record=b5896393.

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Wong Wei-yan.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (leaves 221-242).
Abstracts in English and Chinese.
Thesis committee --- p.i
Declaration --- p.ii
Acknowledgements --- p.iii
Abstract in Chinese --- p.iv
Abstract in English --- p.vi
List of abbreviations --- p.viii
List of figures --- p.xi
List of tables --- p.xv
Content: --- p.xvi
General introduction --- p.1
Aldehyde dehydrogenase superfamily --- p.3
Background of antiquitin --- p.5
Plant antiqutins (ALDH7B) --- p.5
Animal antiquitins (ALDH7A) --- p.8
Human antiquitin information on NCBI --- p.14
Rationale of studying the inducibility of annquitin and overexpression of it in HEK293 and HepG2 cells --- p.16
Flowchart 1 Procedure of antiquitin expression studies in the HEK293 and HepG2 cells under stress --- p.19
Flowchart 2 Procedure to study antiquitin expression in the HEK293 and HepG2 cells after in silico promoter search --- p.20
Flowchart 3 Procedure to study antiquitin overexpressed HEK293 and HepG2 cells --- p.21
Chapter Chapter 1 --- Inducibility of antiquitin in the HEK293 and HepG2 cells under hyperosmotic stress
Chapter 1.1 --- Introduction --- p.22
Chapter 1.1.1 --- Cellular response to hyperosmotic stress --- p.22
Chapter 1.1.2 --- Methods to study the responses of cells under hyperosmotic stress --- p.24
Chapter 1.2 --- Materials --- p.26
Chapter 1.2.1 --- Cell culture media --- p.26
Chapter 1.2.2 --- Buffers for RNA use --- p.26
Chapter 1.2.3 --- Buffers for DNA use --- p.27
Chapter 1.2.4 --- Other chemicals --- p.27
Chapter 1.3 --- Methods --- p.28
Chapter 1.3.1 --- Culture of HEK293 and HepG2 cells --- p.28
Chapter 1.3.2 --- Hyperosmotic stress on HEK293 and HepG2 cells --- p.29
Chapter 1.3.3 --- MTT assay --- p.29
Chapter 1.3.4 --- Total RNA extraction --- p.30
Chapter 1.3.5 --- Reverse transcription polymerase chain reaction (RT-PCR) --- p.30
Chapter 1.3.6 --- Polymerase chain reaction (PCR) --- p.31
Chapter 1.3.7 --- Quantification of PCR products --- p.31
Chapter 1.3.8 --- Statistical analysis --- p.33
Chapter 1.4 --- Results --- p.34
Chapter 1.4.1 --- Viability of HEK293 and HepG2 cells under hyperosmotic stress --- p.34
Chapter 1.4.2 --- Validation of RNA quality --- p.34
Chapter 1.4.3 --- Validation and determination of PCR conditions --- p.40
Chapter 1.4.4 --- Inducibility of antiquitin in HEK293 cells under hyperosmotic stress
Chapter 1.4.5 --- Inducibility of antiquitin in HepG2 cells under hyperosmotic stress --- p.43
Chapter 1.4.6 --- Inducibility of aldose reductase under hyperosmotic stress --- p.43
Chapter Chapter 2 --- "In silico studies of human antiquitin promoter, genomics sequences and open reading frame" --- p.54
Chapter 2.1 --- Introduction --- p.54
Chapter 2.1.1 --- Eukaryotic promoters --- p.55
Chapter 2.1.2 --- Key events in transcriptional initiation --- p.55
Chapter 2.1.3 --- Alternative splicing of mRNA --- p.57
Chapter 2.1.4 --- Bipartite nuclear localization signal (NLS) --- p.57
Chapter 2.2 --- Methods --- p.60
Chapter 2.2.1 --- Putative promoter studies of human antiquitin --- p.60
Chapter 2.2.2 --- Putative promoter studies of Arabidopsis thaliana antiquitin --- p.60
Chapter 2.2.3 --- Analysis for the alternative splicing of human antiquitin mRNA --- p.60
Chapter 2.2.4 --- Analysis for the nuclear localization signal (NLS) of human antiquitin amino acid sequence --- p.61
Chapter 2.2.5 --- Nucleotide / amino acid sequence analyses --- p.61
Chapter 2.3 --- Results --- p.62
Chapter 2.3.1 --- Computer search for the putative cis-acting elements on human antiquitin promoter --- p.62
Chapter 2.3.2 --- Comparison of cis-acting elements found on human antiquitin promoter with those on Arabidopsis thaliana antiquitin promoter --- p.62
Chapter 2.3.3 --- Possibilities of alternative splicing isoforms of human antiquitin
Chapter 2.3.4 --- Possibilities of bipartite nuclear localization signals on human antiquitin protein --- p.83
Chapter Chapter 3 --- Overexpression of antiquitin in HEK293 and HepG2 cells and their characterization
Chapter 3.1 --- Introduction --- p.86
Chapter 3.1.1 --- Cell cycle of a human somatic cell --- p.88
Chapter 3.1.2 --- Detection of changes in the transcriptome --- p.90
Chapter 3.1.3 --- Human genome U133 Plus 2.0 array --- p.95
Chapter 3.1.4 --- Detection of changes in the proteome --- p.96
Chapter 3.1.5 --- MALDI-TOF MS --- p.97
Chapter 3.2 --- Materials --- p.99
Chapter 3.2.1 --- Solutions for cell culture use --- p.99
Chapter 3.2.2 --- Solutions for cloning --- p.99
Chapter 3.2.3 --- Buffers for cell cycle analysis --- p.99
Chapter 3.2.4 --- Buffers for two-dimensional (2D) electrophoresis --- p.100
Chapter 3.2.5 --- Solutions for silver staining --- p.101
Chapter 3.2.6 --- Solutions for Coomassie blue protein staining --- p.102
Chapter 3.2.7 --- Solutions for Western blotting --- p.102
Chapter 3.2.8 --- Solutions for mass spectrometry --- p.103
Chapter 3.3 --- Methods --- p.104
Chapter 3.3.1 --- Hypoosmotic stress --- p.104
Chapter 3.3.2 --- Heat shock --- p.104
Chapter 3.3.3 --- Oxidative stress treatment
Chapter 3.3.4 --- Chemical hypoxia --- p.104
Chapter 3.3.5 --- Treatment of forskolin --- p.106
Chapter 3.3.6 --- Culture of SHSY5Y cells and its differentiation --- p.106
Chapter 3.3.7 --- Cloning of pBUDCE4.1/ATQ --- p.106
Chapter 3.3.8 --- PCR product purification --- p.107
Chapter 3.3.9 --- Preparation of pEGFP.N1 vector for co-transfection --- p.109
Chapter 3.3.10 --- Transfection of HEK293 and HepG2 cells --- p.109
Chapter 3.3.11 --- Assays to characterize transient transfected HEK293 and HepG2 cells --- p.110
Chapter 3.3.11.1 --- Transfection efficiency monitoring --- p.110
Chapter 3.3.11.2 --- Cell cycle analysis --- p.112
Chapter 3.3.11.3 --- Cell doubling time measurement --- p.112
Chapter 3.3.11.4 --- Stress responsiveness --- p.113
Chapter 3.3.11.5 --- Oligonucleotide array analysis --- p.113
Chapter 3.3.11.5.1 --- Total RNA extraction --- p.113
Chapter 3.3.11.5.2 --- Oligonucleotide array preparations --- p.113
Chapter 3.3.11.5.3 --- Data analysis --- p.114
Chapter 3.3.11.6 --- Two-dimensional (2D) electrophoresis --- p.115
Chapter 3.3.11.6.1 --- Total protein extraction --- p.115
Chapter 3.3.11.6.2 --- Protein quantification --- p.115
Chapter 3.3.11.6.3 --- First dimension electrophoresis: isoelectric focusing (IEF) --- p.115
Chapter 3.3.11.6.4 --- Second dimension electrophoresis: SDS- --- p.116
Chapter 3.3.11.6.5 --- Silver staining --- p.116
Chapter 3.3.11.6.6 --- Spots detection --- p.117
Chapter 3.3.11.7 --- Preparations of samples for MALDI-TOF MS --- p.117
Chapter 3.3.11.7.1 --- Silver de-staining --- p.117
Chapter 3.3.11.7.2 --- In-gel tryptic digestion --- p.118
Chapter 3.3.11.7.3 --- Peptide extraction --- p.118
Chapter 3.3.11.7.4 --- ZipTip® samples desalting and concentrating --- p.119
Chapter 3.3.11.7.5 --- MALDI-TOF MS --- p.119
Chapter 3.3.11.8 --- Western blotting --- p.119
Chapter 3.3.11.8.1 --- Antibodies probing --- p.120
Chapter 3.3.11.8.2 --- Enhanced chemiluminescence's (ECL) assay --- p.121
Chapter 3.4 --- Results --- p.122
Chapter 3.4.1 --- Inducibility of antiquitin in HEK293 cells under xenobiotic stimulus --- p.122
Chapter 3.4.2 --- Inducibility of antiquitin in HEK293 and HepG2 cells under chemical hypoxia --- p.122
Chapter 3.4.3 --- Inducibility of antiquitin in HEK293 and HepG2 cells under hypoosmotic stress --- p.122
Chapter 3.4.4 --- Inducibility of antiquitin in HEK293 and HepG2 cells under heat shock --- p.122
Chapter 3.4.5 --- Inducibility of antiquitin in HEK293 and HepG2 cells under forskolin challenge --- p.128
Chapter 3.4.6 --- Expression of antiquitin in differentiating SHSY5Y cells by retinoic acid and N2 supplement --- p.128
Chapter 3.4.7 --- Overexpression of antiquitin in HEK293 and HepG2 cells --- p.128
Chapter 3.4.8 --- Viability of transfected HEK293 and HepG2 cells under hyperosmotic stress --- p.136
Chapter 3.4.9 --- Cell doubling times of transfected HEK293 and HepG2 cells --- p.143
Chapter 3.4.10 --- Cell cycle analysis of transfected HEK293 and HepG2 cells --- p.143
Chapter 3.4.11 --- "Western blot analysis of cyclin D, cyclin A and cyclin B of transfected HEK293 and HepG2 cells" --- p.148
Chapter 3.4.12 --- RNA quality control tests for oligonucleotide array analysis --- p.148
Chapter 3.4.13 --- Oligonucleotide array analysis on transfected HEK293 and HepG2 cells --- p.155
Chapter 3.4.14 --- Two-dimensional electrophoresis of transfected HEK293 and HepG2 cells --- p.169
Chapter 3.4.15 --- MALDI-TOF MS of transfected HEK293 and HepG2 cells --- p.169
Chapter 3.4.16 --- Genes and proteins upregulnted in the antiquitin transfected HEK293 and HepG2 cells --- p.190
Discussion --- p.197
Reference --- p.221
Appendix Materials used in the project --- p.243

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34

Allen, Katherine. "The effects of troglitazone and PMA on AMPK in HepG2 cells". Thesis, 2016. https://hdl.handle.net/2144/16783.

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Type 2 diabetes, as well as other metabolic diseases, is an increasing global health concern and many of the mechanisms of both the disease and its current drug treatments have not been fully described. It has been shown that the anti-diabetic class of drugs, the thiazolidinediones, work via both a known PPARγ-dependent, and a lesser known PPARγ-independent mechanism of action. This PPARγ-independent mechanism likely involves the metabolic regulatory molecule AMPK, which has a newly elucidated inhibitory site of phosphorylation at Ser485/Ser491. In this study we sought to determine if the thiazolidinedione troglitazone affects AMPK in HepG2 liver cells via phosphorylation at both the known Thr172 site as well as the letter understood Ser485 site. We also looked for potential upstream kinases of the Ser485 site by comparing our results to recently proposed mechanisms of phosphorylation here. HepG2 cells were cultured in the lab and treated with troglitazone to determine time- and dose- dependent effects on AMPK. We also treated cultured HepG2 cells with PMA as well as troglitazone and PMA in order to compare mechanisms of action of troglitazone on AMPK. Results were analyzed using common western blot techniques and statistical analysis. Our data found that troglitazone increased AMPK activity by increasing phosphorylation at Thr172 in a time- and dose- dependent manner. The inhibitory site Ser485 was also increasingly phosphorylated with troglitazone treatments, although the net result of troglitazone treatment remained AMPK activation. The recently elucidated results from our laboratory showing the mechanism of p-AMPK Ser485 phosphorylation via PKD after PMA treatment also occurred in HepG2 cells, although this did not appear to be the mechanism by which troglitazone phosphorylated AMPK at Ser485. These data support the current research that there is an AMPK mediated PPARγ-independent mechanism of troglitazone treatment for type 2 diabetes and other metabolic diseases. The results do however bring into question the full effects of the drug on AMPK at a molecular level and leaves room for new research in this area, specifically the exact mechanism by which troglitazone phosphorylates AMPK at Ser485. Our data also brings up new questions as to the simultaneous phosphorylation of AMPK at both Thr172 and Ser485 and what this means for the activity of the molecule as a whole, a current area of critical research. Lastly our data support the newly elucidated mechanism of AMPK phosphorylation at Ser485 via PKD1, an exciting and novel discovery and potential target for therapeutic intervention.

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35

Hsu, Chih-Wen, i 徐智文. "A Mechanical Study on the anti-attachment of HepG2 Tumor Cells". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/89385675631049495410.

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碩士
淡江大學
機械與機電工程學系碩士班
99
For metastasis of tumor cell invade into the circulatory system, it have to do with tumor-cell of detachment and attachment. This work presents the first part of a new framework for preventing the tumor-cell of carcinoma in situ transition from one organ to others. Using an ECIS (electric cell-substrate impedance sensing) chip coated with glutaraldehyde (GA)-crosslinked gelatin patterns suitable for cell attachment, the author monitor the cell adhesion situation not only by optical microscope but also by electrical means. This cell-culture experiment with 1-hour time resolution so far demonstrates that the attachment moment for HepG2 on gelatin surface is no longer than 4 hours after the cell dosing and these tumor cells cannot stay on GA-crosslinked gelatin surface for more than 7 hours. The second part of experiment is dynamic. The author design an experiment and a microfluidic chip for investigating the relationship between the metastasis and the surface morphology of blood vessels. Using RIE (reactive ion etch) to change the inner wall morphology of PDMS. To different inner wall of PDMS roughness, the ability of cell adhesion is different. When tumor-cell through the microchannel, it may pass or get stuck. It’s mean that capillary may plugged by tumor-cell, or still smooth. Finally, to explore the adhesion of tumor-cell and blocking when tumor-cell into the liver through the hepatic portal vein. It can assist in the prevention and treatment of cancer, such as diet, drug, gene therapy research.

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36

Shiu, Shin-Mau, i 許新茂. "Monacolin K enhances lipolysis through SIRT1/AMPK pathway in HepG2 cells". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/37077140136760129745.

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碩士
中臺科技大學
醫學檢驗生物技術系碩士班
100
Monacolin K, originally isolated from Monascus spp. as the secondary metabolite, has been previously demonstrated to reduce the synthesis of cholesterol in association with a decrease in low density lipoprotein (LDL) and an increase in high density lipoprotein (HDL) by inhibiting the enzymatic activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. In this study, monacolin K was found to increase the protein level of SIRT1 and the phosphorylation level of AMP-activated protein kinase (AMPK) in HepG2 cells, and the effects have been reported to be associated with lower fatty acid synthesis and higher lipid metabolism. Furthermore, we also found that monacolin K inhibited the activity of acteyl CoA carboxylase (ACC) and caused the nuclear translocation of FoxO1 together with their changes in phosphorylation level. To investigate the involvement of monacolin in lipolysis, the protein expression levels of adipocyte triglyceride lipase (ATGL), fatty acid synthase (FAS),sterol regulatory element-binding protein 1 (SREBP1) were determined by western blotting analysis. The results showed that monacolin increased ATGL but decreased FAS and SREBP1 expressions, and some of the effects were counteracted by nicotinamide or compound C, inhibitors of SIRT1 or AMPK. The results were connected with the intracellular lipid level that was decreased by monacolin using the method of oil red staining. In summary, monacolin enhances lipolysis through AMPK/SIRT1 pathway in HepG2 cells.

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37

Yi-Ling i 陳怡伶. "Studies on the Toxic Effects of 3,3’-Dichlorobenzidine in HepG2 Cells". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53571676125383662066.

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碩士
高雄師範大學
生物科技系
97
3,3’-dichlorobenzidine (DCB) is a benzidine-based azo dye. This study investigated the DCB of the toxic effects of Hep G2 cells. In MTT assay, results showed that DCB can induce DNA damage in HepG2 cells with the manner of dose-dependent trend. The proteomics and flow cytometry were used for the toxic effect in cells-treated with 100µM of DCB. The use of flow cytometry in combination with Annexin V-FITC/PI staining showed that 100μM DCB can result in 40% of Hep G2 cells producing apoptosis. In addition, using of flow cytometry combined with DCFH-DA staining, we found that Hep G2 cells could cause the generation of ROS after DCB treatment. The presence of a ROS scavenger ( N-acetyl-L-cysteine,NAC ) didn’t block cytotoxity induced by DCB. By analyzing the data of proteome; among the differential proteins, 9 proteins were up-regulated and 37 proteins were down-regulated, which were detected in the range of pI 4.5-5.5. In pI 5.5-6.7, that the amounts of 13 proteins increased, whereas 66 proteins were decreased in amounts. These differential proteins were TXNDC5 protein, prolyl 4-hydroxylase, beta subunit precursor, apolipoprotein A-IV precursor, SMT3A protein, RAB37, member RAS, oncogene family, isoform CRA_e . In order to confirm that Hep G2 cells treated with DCB caused apoptosis, we used western blot to detect apoptosis-related proteins; caspase 3 and bax. Our data showed that DCB can induce caspase 3 overexpression and decrease Bcl-2/Bax ratio in HepG2 cells with the manner of time- trend after 24 treatment with DCB, respectively. The current study suggested that DCB can activate of the caspase-dependent apoptotic pathway，but didn’t cause via ROS generation

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38

Tung, Po-Yuan, i 董伯元. "Effects of acidic extracellular pH on Adherens Junctions of HepG2 cells". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34233021523465313868.

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碩士
臺灣大學
解剖學暨生物細胞學研究所
95
An acidic extracellular pH (pHe) is a feature of the tumor microenvironment and increases tumor invasion. However, little attention has been paid to the role of adherens junctions (AJs) in acidic pHe-induced cell invasion. We hypothesized that an acidic pHe may increase cell migration by disruption of the AJ via modulation of cell-cell adhesion molecules. Our results showed that incubation of HepG2 cells in acidic medium (pH 6.6) induced a phenotypic change from tight cell clusters to dispersed cells with a flattened morphology and this change was accompanied by an increase of cell migration. Rapid phosphorylation of c-Src kinase was detected after incubation of the cells at pH 6.6. In comparison to cells incubated at pH 7.4, the decrease of E-cadherin and β-catenin staining at AJ and an increase in E-cadherin-containing cytoplasmic vesicles were observed in pH 6.6-treated cells. The lower protein levels in the membrane fractions of E-cadherin and β-catenin were also noticed. Pretreatment with a Src kinase inhibitor, PP2, prevented the acidic pHe-induced decrease in protein levels and immunoreactivity of membrane-bound E-cadherin and β-catenin. The acidic pHe-induced c-Src activation increased tyrosine phosphorylation of E-cadherin and β-catenin, and resulted in the decreased amount of E-cadherin associated with β-catenin. These effects may be caused by disruption of cadherin/ catenin complex through tyrosine phosphorylation β-catenin at Y654 in response to c-Src kinase activation. Furthermore, the protein amounts of Hakai （cbl-like ubiquitin ligase） bound to E-cadherin and the levels of ubiquitinated E-cadherin were both increased by pH 6.6 treatments by immunoprecipitation and immunoblotting analysis. The results inferred that the activation of c-Src kinase led to the binding of Hakai to tyrosine phosphorylated E-cadherin at AJ, which promoted increased ubiquitination of E-cadherin and accelerated E-cadherin endocytosis. In addition, other mechanisms may contribute to the acidic pHe-induced downregulation of membranous E-cadherin. In pH 7.4-treated cells, cortical actin bundles inserted at AJ. pH 6.6 treatment caused the disappearance of E-cadherin staining coincided with the dissolution of junctional actin bundle, and induced a rapid activation of PKCε. Our results showed that the inhibition of PKCε by eV1-2 prevented the depolymerization of junctional actin bundles and downregulation of junctional E-cadherin induced by acidic pHe. These data confirmed the hypothesis that normal distribution of E-cadherin at AJ is intimately associated with cortical actin bundles. Either inhibition of PKCε by eV1-2 or of c-Src by PP2 prevented acidic pHe induecd cell migration. Acidic pHe enhanced the association of active PKC

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39

Wang, Chun-Hui, i 王君蕙. "Effect of Mitochondrial Stress on HIF-1α Expression in HepG2 Cells". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64579080784053969725.

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碩士
國立陽明大學
藥理學研究所
95
Mitochondrial retrograde signaling is a pathway of communication from mitochondria to the nucleus and influences many cellular activities under both normal and pathophysiological conditions. Nevertheless, little is known about the retrograde signaling in mammalian system. Many years ago, Dr. Warburg proposed a link between defects in mitochondrial physiology and tumorigenesis. After that, the relationship between mitochondria and cancer was further investigated. Recently, somatic mutations and reduced copy number of mitochondrial DNA (mtDNA) have been found in most of human cancers. In this study, I thus proposed that mitochondrial dysfunction could lead to a change in nuclear transcription factor activity and it might modulate cancer progression. Because HIF-1α is an important transcription factor participated in cancer progression, the effect of mitochondrial dysfunction on HIF-1α expression and activity was evaluated to test this hypothesis. In this study, it was found that HIF-1α protein level was lower in ρ0 (mtDNA-depletion cells) than their parental human osteosarcoma 143B cells. Moreover, treatment with chloramphenicol (CAP, an inhibitor of mitochondrial translation) decreased the HIF-1α protein level in 143B cells, indicating that mitochondrial functions are critical for maintaining HIF-1α level. In addition, both the protein level and transactivation activity of HIF-1α were decreased in HepG2 cells under several mitochondrial stresses, such as CAP, ethidium bromide (EtBr, an inhibitor of mitochondrial transcription and replication), rotenone and antimycin A (inhibitors of mitochondrial electron transport chain), oligomycin (an inhibitor of mitochondrial ATP synthase), or carbonyl cyanide m-chlorophenyl hydrazone (CCCP, a mitochondria-specific ionophore). Mitochondrial stresses also reduced the mRNA expression of several HIF-1α downstream target genes (MMP2、LDHA and CAIX). The mechanism underlying mitochondrial stress-induced HIF-1α depletion was further dissected, and it was found that the protein synthesis of HIF-1α was inhibited under mitochondrial stress, but the protein degradation was not changed. In addition, mitochondrial stresses decreased p70S6K phosphorylation, and this might contribute to the repression of HIF-1α protein de novo synthesis. Based on these observations, it is suggested that mitochondrial stresses inhibited HIF-1α de novo synthesis in HepG2 cells. Because HIF-1α plays a critical role in cancer progression, it has been proposed as a drug target for cancer therapy. The finding in this study might provide a direction in the development of anticancer drugs.

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40

Kang, Shih-Pei, i 康詩珮. "Study of Glycyrrhiza uralensis against NF-κB Activation in HepG2 Cells". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/02907314063135520957.

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碩士
國立陽明大學
傳統醫藥研究所
99
Liver fibrosis usually results from liver inflammation. When liver is damaged, hepatocytes live in an inflammatory microenvironment. Proinflammatory cytokine, TNF-α stimulates hepatocytes via NF-κB. This study was aimed to screen potential herbs against NF-κB activation in HepG2 cells. Human hepatoma cell lines were used to imitate human hepatocytes in this study. HepG2 cells were stimulated by TNF-α with or without herbs. NF-κB reporter gene assay was used to screen herbs against NF-κB transcription activity. Cell viability was measured by MTT assay. TNF-α-induced phosphorylation of IκBα and p65 translocation were measured by Western blotting. TNF-α-induced mRNA expression was measured by quantitative real-time PCR. Results showed that TNF-α-induced NF-κB transcription activity was 255 ± 7 % of control in NF-κB reporter gene assay. Overall, 47 herbs were screened. Glycyrrhiza uralensis was selected for further study. Glycyrrhetinic acid inhibited TNF-α-induced NF-κB transcription activity in a concentration-dependent manner. Glycyrrhetinic acid also inhibited TNF-α-induced phosphorylation of IκBα and p65 translocation. TNF-α-induced iNOS mRNA expression was inhibited by glycyrrhetinic acid as well. In conclusion, G. uralensis and one of its constituents, glycyrrhetinic acid inhibited TNF-α-induced mRNA expression, possibly via attenuating activation of NF-κB in HepG2 cells.

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41

Lo, Hsin-Yi, i 羅欣宜. "Study On The Regulation Of Metabolism In HepG2 Cells By Astragalosides". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/65219895023490738429.

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碩士
國防醫學院
生物化學研究所
100
Astragalosides are major components of astragalus membranaceus and are attributed for most of its anti-diabetes pharmacological activities. Despite extensive studies, the mechanism of action of astragalosides remains to be clarified. In our previous studies, purified astragalosides AS4 and AA were shown to enhance glucose uptake in Caco-2 intestine cells. In addition, these compounds also enhanced energy production by significantly increasing the intracellular level of ATP in HepG2 hepatic cells. Liver plays a key role in the regulation of organism energy metabolism. In an effort to clarify the mechanism of the gluco-regulatory activity of astragalosides, the effect of astragalosides on energy metabolism was studied in human HepG2 cells. The effect of astragalosides AS4, AA on glucose uptake was analysed using the non-metabolizable, 14C-2-Deoxyglucose as tracer. The effects of AS4 and AA on glycogen and lipid synthesis were examined by analyzing the incorporation of 14C -D-Glucose incorporated into glycogen and lipid in the HepG2 cells. To study the effect of AS4 and AA on glycolysis, the level of lactic acid accumulated in the medium were determined, in accordance. In this study, we showed that AS4 and AA significantly increased the glucose uptake of HepG2 cells. AS4 and AA significantly increased the glycogen synthesis and reduced lipid synthesis in HepG2 cells treated with AS4 and AA for 1h. However, prolonged treatment of AS4 and AA for 24 h increased the glycogen and lipid synthesis significantily. In addition to glycogen and lipid synthesis, we found treatment of AS4 and AA for 1h reduced the level of lactate (the metabolite of anaerobic glycolysis) in the medium, but increased the level of lactate in the medium from HepG2 cells treated for 24h. To investigate the mechanism of these astragalosides, the effect of AS4 and AA on PI3K and AMPK signaling pathways were examined, respectively, by measuring the phosphorylation levels of Akt in PI3K pathway, and AMPK and ACC in AMPK pathway. Our results showed that PI3K pathway is involved as the phosphorylation level of Akt increased in AS4 and AA incubated cells. Moreover, the AS4 and AA -induced Akt phosphorylation was completely blocked in the presence of the PI3K inhibitor, LY294002. In addition to PI3K pathway, AMPK signaling pathway is also involved in the action of astragalosides as the phosphorylation level of AMPK and ACC was significantly increased in AS4 and AA treated HepG2 cells. In summary, we demonstrated that astragalosides AS4 and AA significantly increased glucose uptake in HepG2 cells. In glycogen and lipid metabolism, AS4 and AA displayed opposite effects by decreasing or increasing lipid synthesis upon acute- or prolonged- treatment , but displayed identical effects by increasing glycogen stnthesis, respectively. The signaling mechanism of AS4 and AA was at least partly through the activation of PI3K and AMPK pathways in HepG2 cells.

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42

Chu, Ching-yu, i 朱靜郁. "Anti-angiogenesis of Ursolic acid and Oleanolic acid on HepG2 Cells". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/29354015805483657753.

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碩士
慈濟大學
生命科學系碩士班
99
Hepatocellular carcinoma (HCC) is one of the most malignant tumors with high rate of recurrence and metastasis. Angiogenesis is a very important process that mediates tumor growth and metastasis, and can be used as a therapeutic target among all the strategies for many cancers. Ursolic acid (UA) and its derivative oleanolic acid (OA), are two glycyrrhetinic acid related pentacyclic triterpenoids that we had found anti-tumor effects in HepG2 cells in previous studies. The aim of this study is to further investigate whether UA and OA have the inhibitory effect on angiogenesis in HepG2 cells. Our results indicate that both UA and OA inhibit cell proliferation in a dose-dependent manner by EdU cell proliferation assay and exhibit anti-angiogenesis in a dose-dependent manner are examined by in vitro analysis including wound-healing, transwell and capillary-like tube formation assay. We observed that both UA and OA could potently inhibit angiogenesis by chicken chorioallantoic membrane (CAM) ex vivo assay and matrigel plug in vivo assay. Our investigations showed that UA and OA inhibit angiogenesis directly through phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)-mediated pathways that are important signal molecules among all the pathways associated with cells angiogenesis. This study revealed that both UA and OA, in addition to their anti-tumor effects, can suppress tumor growth through inhibition of tumor angiogenesis in vitro, ex vivo and in vivo via targeting PI3K/AKT and MAPK/ERK signaling pathways. We expect that UA and OA may effectively be used as a therapeutic strategy for HCC in the future.

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43

Chen, Guei-Lan, i 陳貴蘭. "Study of the mechanism of iron chelatingagent-deferoxamine induced cell death in hepatoma HepG2 cells". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/77775570818750334196.

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碩士
國立陽明大學
藥理學研究所
88
Iron is required for cell proliferation and excess iron may be involved in the development of hepatocellular carcinoma. In this study, the effects of deferoxamine (DFO), an iron chelator, in human hepatoma HepG2 cells was investigated. DFO treatment dose dependently reduced the viability and cell growth of HepG2 cells. Moreover, DFO treated cells showed morphological changes including an increase of cell volume as well as intracellular granules. Flow cytometric analyses showed that DFO treatment resulted in an increase of cells in G1-S phase and a decrease of cells in G2-M phase. The levels of p53 and p21 proteins were significantly increased in a time dependent manner after treatment with 25 micro M DFO. The induction of p53 by DFO was abolished by hydrogen peroxide and ferric ammonium citrate. On the other hand, DFO treatment of HepG2 cells resulted in decreased intracellular hydrogen peroxide level with no change in superoxide level. In order to determine the role of hypoxia-inducible factor (HIF)-1α in mediating DFO induced up-regulation of p53, it was found that DFO treatment of HepG2 cells also resulted in increased level of HIF-1α. Moreover, to compare the effects of DFO to mimosine, a well-characterized iron chelator, it was found that both drugs similarly altered cellular levels of p53 and HIF-1α proteins. Using flowcytometry, it was further found that after treatment of HepG2 cells with 25 micro M DFO for 18hr, increased level of transferrin receptors was found on cell surface, indicating that the cells were iron-starved. These results demonstrated that (1) DFO induced accumulation of G1-S cells may involve a p53-dependent pathway (2) The induction of p53 appears to correlate with decreased level of intracellular hydrogen peroxide. (3) DFO treated HepG2 cells showed elevation of HIF-1α and transferrin receptor and the increase of HIF-1α may be involved in regulation of the expression of p53.

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44

Lii, Herng-Jiun, i 李恆君. "Part I Study of enhancement effect of Paclitaxel-induced apoptosis by Esculetin in HepG2 cells Part II Study of antiproliferation effect of Ixeris chinensis in HepG2 cells". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/45418413980626884260.

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碩士
中山醫學大學
生物化學研究所
91
Part I: Esculetin (EST) is a phenolic natural antioxidant of coumarin derivative. In modern times, there are more and more researches about the biological and biochemistry activity of Esculetin. Latest finding is Esculetin can inhibit the survival of human lukemia and breast cancer cells. However, the antiproliferation mechanism of Esculetin on cacer is not well understood. Palictaxel was extracted from the bark of Texus brevifolia in 1967 and was applied spreadly on the therapy of cancer. It’s a popular research trend about how to lower the toxicity on humanbody and still keep the clinical therapy effect. The goal to lower the dosage, side effect and drug resistance might be achieved by a combination treatment of Paclitaxel and other agents. In this study we treated Esculetin and Palitaxel together and had a finding that Esculetin can enhance the effect of Paclitaxel-induced apoptosis. Base on the finding, we were going to discuss it’s molecular mechanism. We exposed Paclitaxel alone on HepG2 cell and JNK and ERK pathways were activated. Three kinds of MAPK kinase inhibitors (PD98059, SB203580, SP600125) and Esculetin were added with Palitaxel. This experiment confirmd that activities of JNK was necessary for Palitaxel to induce the apoptosis of HepG2 cell by Western blotting and flow cytometry. Howevr, when ERK inhibitors (PD98059 and Esculetin) was added, the apoptosis enhanced by the decrease of ERK activation. It demonstrated that Esculetin can enhance the effect of Paclitaxel-induced apoptosis in HepG2 cells by inhibiting the antiapoptotic ERK pathway. Therefore JNK-dependent apoptosis could react much completely in the cells. Part II: After human striving for decades, there is a huge progress on the medicine therapies of maligmant tumor. Modern science develops speedly especially life science which is probing the secret of carcinogen. It sets a milestone for researches of antitumor drug. The success of antitumor drug like Palictaxel reveals the importance to discover new mechanism and unique chemical structure of cytotoxicity drug from the nature. Ixeris chinensis is a kind of popular herb for bleeding, swelling, inflammatory, and pain. Previous study showed Ixeris chinensis to be well antioxidant. In this study, we found the crude extract of Ixeris chinensis having cytoxicity to tumor cell lines. After analyzed the component and activity, we discovered Luteolin a kind of flavonoid inhibited the growth of human hepatoma cell-HepG2. Taking use of flow cytometry, nuclear stain assay, DNA fragmentation assay, we confirmed that Luteolin induced apoptosis. We found that Luteolin induced HepG2 cells apoptosis through increase expression of CPP32 and its substrate, PARP, had been degraded. The upstream proteins of apoptosis like cytochrome C, Bax, Bak increased distinct and p53, MAPK kinase proteins were activated. There was a conclusion that Ixeris chinensis had antioxidant ability and can inhibit the proliferation of HepG2 cells. Luteolin isolated from Ixeris chinensis got better inhibit effect and it can even induce apoptosis. The result showed Ixeris chinensis had helth protection and cure function that is worth advanced development.

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45

楊德群. "Studies of Ginsenosides on Glucose Absorption in Caco2 Cells and Intracelluar ATP Level in HepG2 Cells". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/02913673854393858953.

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碩士
國防醫學院
藥學研究所
92
Ginseng, the root of Panax ginseng, is a very old and well-known drug in traditional Chinese medicine used mainly to reinforce qi and invigorate the function of the spleen. Being interested in exploring of the mechanism of reinforcement qi of ginseng, the investigation of P. notoginseng, the same genus of ginseng, was undertaken in this study to prepare ginsenosides which were mainly active components of ginseng. The alcohol extract of the root of P. notoginseng was separated and purified by adsorbent resin, silica gel and reversed-phase chromatography to give five known ginsenosides, ginsenoside Rb1 (1), Rg1 (2), Rh1 (3), Re (4), and notoginsenoside R1 (5). Then, ginsenoside Rb1 and Rg1 were hydrolysis by naringinase to yield metabolites, ginsenoside F2 (6), compound K (7), as well as ginsenoside F1 (8) and 20(S)-protopanaxatriol (9). These compounds were identified by comparison of their physical and spectral data with those reported in the literature and authentic samples. The glucose absorption and ATP assay were used as bioactivities experimental models. The glucose absorption could be increased by NL-WLC-P01, P02, P03, P04, P06, and P08 in Caco 2 monolayer system, while NL-WLC-P02 especially enhanced 104% glucose absorption at dose of 0.001 μM, whereas, NL-WLC-P05 (0.001 μM) and P07 (0.01 μM) decreased 50% glucose absorption. NL-WLC-P02 could enhance about 30% ATP contained in HepG2 cells. The mechanism of these effects remains to be clarified.

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46

陳琦斐. "Evaluate the Antiproliferative Effects of Perilla frutescens Extract on Human Hepatoma Cells (HepG2) and Differentiating Apoptotic Related Genes in the Extract Treated HepG2 Cells Using DNA Microarray Analysis". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/83113652167715450840.

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碩士
國立交通大學
生化工程研究所
91
Background: Hepatocellular carcinoma is one of the most common malignant tumors in oriental countries. However, effective drugs for treating this disease are still unavailable. Emerging evidence has demonstrated that many natural products isolated from plant sources possess antitumor properties. Interest in exploiting traditional medicines for prevention or treatment of cancer is increasing. In cancer treatment, the therapeutic goal is to trigger tumor-selective cell death. Apoptosis represents a universal and exquisitely efficient cellular suicide pathway. Therefore, several studies have shown that some of chemotherapeutic agents isolated from Chinese herbal extracts exert their anticancer activity by inducing cancer cells apoptosis. In the present study, 20 herbal extracts were prepared and used to evaluate the effect and mechanism of growth inhibition on human hepatoma cells (HepG2). Materials and methods: In this study, MTT cell viability assay was used to measure the antiproliferative effects of 20 herbal extracts on HepG2 cells. Two cell death types, apoptosis and necrosis, were distinguished by DNA fragmentation detection and by several fluorescent staining such as Hoechst 33342, TUNEL assay, and Annexin V-FITC staining assay. Agilent human 1A oligo microarray containing 22,575 oligonucleotide probes was used to screen the differentially expressed genes in the HepG2 cells treated with Perilla frutescens extract. Results and discussion: Among the 20 Chinese herbal extracts tested, P. frutescens showed the best efficiency in growth inhibition on HepG2 cells. The cytotoxicity of P. frutescens extract was also evaluated in porcine liver cells. Significantly lower cytotoxicity on such non-cancer cells was observed when compared with HepG2 cells. The results of DNA fragmentation detection and several fluorescent staining indicated that the P. frutescens extract could trigger the pathway of cellular apoptosis and resulting the cell death in HepG2 cells. The apoptosis related genes were further analyzed using DNA microarray. Based on the result of differentially expressed genes, we proposed two pathways in which P. frutescens extract induced HepG2 cells apoptosis. The first one was by activating the caspase cascade of death receptor related genes and the second one was by p53 activating the mitochondrial pathway. Conclusion: In vitro assay system, including the cell viability assay, apoptosis determinations of DNA fragmentation, specifically fluorescent staining and DNA microarray analysis, has been established in screening potent anticancer extracts from Chinese herbs. According to the system, we successfully identified the potent anticancer activity of P. frutescens extract. The anticancer effect of P. frutescens extract was proved to be dependent on apoptosis as indicated by DNA microarray analysis.

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47

Chiou, Bin-Hao, i 邱炳豪. "MicroRNA regulation of DNA repair gene expression in4-aminobiphenyl-treated HepG2 cells". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/06983542721089265929.

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碩士
國立中央大學
生命科學系
103
The study goal was to evaluate the effects of 4-aminobiphenyl (4-ABP) on DNA damage based on the regulation of miRNAs to suppress some reducing DNA-repair proteins in human HepG2 cells. In this study, we used comet assay to determine that 4-ABP (0–300 M) induces DNA damage in HepG2 cells after 24 hours. DNA damage signaling pathway-based PCR arrays were used to investigate differential expressed genes response to 4-ABP treatment. In parallel, the miRNAs array was revealed that the expression of 27 miRNAs in 4-ABP-treated cells was at least 3-fold higher than that in the control group. Of these 27 miRNAs, the most significant expression of miRNA-513a-5p and miRNA-630 was further validated by qRT-PCR, which was predicted to target to RAD18、XRCC2 and FANCG genes, respectively, via bioinformatic analysis. In addition, overexpression and knockdown of miRNA-630 and miRNA-513a-5p inversely regulate the expression of RAD18、XRCC2 and FANCG proteins expression levels.　 We found that ROS production is crucial for 4-ABP-induced miR-513a-5p expression and this phenomenon would be abolished by ROS inhibitor N-acetylcysteine. XRCC2 overexpression that the extent of DNA damage will be eminently repaired as well.　Based on these, we indicated the mechanism of 4-ABP→ROS→miR-513a-5p --| XRCC2→DNA damage, and provide a potential application for prevention and therapy in future.

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48

Liou, Tsuei-Ru, i 劉翠茹. "Detoxifying Enzymes Induction Effect of Methyl Gallate in Human HepG2/C3A cells". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/82204328791195210696.

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碩士
國立屏東科技大學
生物科技研究所
97
Detoxifying enzymes system protects the body against the potential harmful exposure to xenobiotics from the environment as well as certain endobiotics. Plant phenols contribute significant biological properties such as anti-inflammatory, antioxidant. Methyl gallate is the major phenol constituents of a lot of nature plant. It was reported that ROS as intracellular signaling molecules could activate of transcription factor NF-E2-related factor 2 (Nrf2) and bind to ARE sequences, which is leading to transcriptional activation of phase II enzymes including GCL and HO-1. This study is designed to assess the effect of methyl gallate induces phase II detoxifying enzymes through activation Nrf2 in HepG2/C3A cell lines. The results showed that methyl gallate has no cell toxicity in HepG2 cell lines under 100μM by MTT assay. We found that methyl gallate enhanced intracellular ROS and activated signaling factor on PI3K and MAPK pathway. In addition, methyl gallate induced Nrf2 translocation into nucleus and activated expression of Nrf2-regulated protein including HO-1, GCL and GLO-1. Eventually, methyl gallate can increase GSH content at 24 hour. This study demonstrated that methyl gallate enhances ROS-induced phase II detoxification enzymes expression.

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49

Silva, Ana Marta Ribeiro da. "Role of mitochondrial p66Shc in nefazodone-induced mitochondrial toxicity on HepG2 cells". Master's thesis, 2015. http://hdl.handle.net/10348/6943.

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Dissertação de Mestrado em Biologia
A Nefazodona (NEF) é um fármaco antidepressivo, usado durante um longo período no tratamento da depressão. Apesar da sua eficácia, este fármaco foi retirado do mercado devido ao aparecimento de diversos casos de lesão hepática em pacientes submetidos a tratamento com NEF. A via de sinalização celular que envolve a proteína p66Shc, e a sua fosforilação na serina 36 (Ser36) após estimulo de stress, foi anteriormente associada à produção de espécies reactivas de oxigénio e à ocorrência de morte celular. De acordo com esta hipótese, a proteína p66Shc é translocada para a mitocôndria após uma situação de stress celular onde participa na produção de ROS, levando ao comprometimento da função mitocondrial e podendo, ainda, desencadear o processo de morte celular. O principal objectivo deste trabalho foi investigar a possibilidade de que esta via de sinalização seja activada na linha celular do carcinoma hepatocelular humano (HepG2) durante o tratamento com NEF. Os resultados obtidos revelaram um aumento do teor de p66Shc em células expostas à nefazodona por um perídodo de 72 h e ainda um surpeendente decréscimo da forma fosforilada desta proteína após o tratamento com NEF. Embora este trabalho não possa comprovar a existência de uma ligação entre a administração de NEF e a activação e translocação da proteína p66Shc, os resultados obtidos corroboram a existência de uma associação entre o tratamento com NEF e o início do processo apoptótico no modelo celular utilizado. O tratamento com NEF levou à diminuição da massa celular, à despolarização mitocondrial e ainda a alterações na morfologia celular, com as células HepG2 a exibirem caracteristicas tipicamente encontradas em células apoptóticas. Foram também encontradas outras evidências consistentes com a activação da apoptose induzida por NEF, como o aumento da população de células apoptóticas, a diminuição da população de células viáveis e o aumento da actividade das caspases. Em suma, os resultados obtidos mostram um aumento dos níveis de ROS após o tratamento com NEF, embora a possibilidade de uma associação entre este aumento e a activação da p66Shc e translocação para a mitocôndria possa estar ocultada devido ao rápido processamento da forma fosforilada da proteína p66Shc.
Nefazodone (NEF) is an antidepressive agent that has been used for several years in the treatment of depression. Despite its efficacy in the treatment of depression, NEF was withdrawn from the market after the development of hepatic injury on several patients upon treatment. p66Shc signalling, which implicates its phosphorylation in ser36 residue (pSer36-p66Shc) upon stress stimuli, has been described to be involved on reactive oxygen species (ROS) generation and cell death. After its phosphorylation p66Shc is thought to be translocated to mitochondria where it leads to further ROS production, disrupting mitochondrial function and possibly triggering of cell death. The main objective of the present work was to investigate whether p66Shc signalling is activated during NEF treatment of a human hepatocellular cell line (HepG2). Our results revealed an increase on p66Shc content after 72 h of incubation with NEF, whereas, surprisingly the content of p66Shc phosphorylated form was decreased after NEF treatment. Although this study was not able to prove the existence of a link between NEF administration and p66Shc activation and consequent translocation to mitochondria, our results support the existence of a link between NEF treatment and apoptosis in the hepatic cell model. NEF treatment led to a decrease in cell mass, mitochondria depolarization and to changes on HepG2 cell morphology, which showed features typical from apoptotic cells. We also found other evidences supporting apoptosis activation upon Nefazodone treatment, such as the increase on late apoptotic cell population, the decrease on viable/early apoptotic cells and an increase of caspases activity. In summary, our data showed an increase of ROS levels upon NEF treatment which although might be associated with p66Shc signaling and its consequent translocation to mitochondria, the fast turn-over of pSer36-p66Shc may be masking these observations.
This work was supported by the Portuguese Foundation for Science and Technology (FCT) and co-funded by COMPETE/FEDER

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50

Ho, I.-Hsin, i 何怡欣. "Study on the regulation of glucose metabolism in HepG2 cells by ginsenosides". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/37403400814943713746.

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碩士
國防醫學院
生物化學研究所
98
Ginsenosides are major components of ginseng and are attributed for most of its pharmacological activities. Despite extensive studies, the mechanism of action of ginseng remains to be clarified. In our previous studies, purified ginsenosides Compound K (CK) and Rg1 were shown to enhance glucose uptake in adipose and muscle cells. In addition, these compounds also enhanced energy production by significantly increase the intracellular level of ATP in hepatic cells. Liver plays a key role in the regulation of whole-body energy metabolism. In an effort to clarify the mechanism of the gluco-regulatory activity of ginseng, the effect of ginsenosides on energy metabolism was studied in human HepG2 cells. The effect of ginsenosides Rg1, CK on glucose uptake was analysed using the non-metabolizable, 14C-2-Deoxyglucose as tracer. The effect of Rg1 and CK on glycogen or lipid synthesis was examined by analyzing the incorporation of 14C -D-Glucose incorporated into glycogen or lipid in the HepG2 cells. To study the effect of Rg1 on gluconeogenesis and glycolysis, the level of glucose and lactic acid accumulated in the medium were determined, respectively. In this study, we showed that Rg1 and CK significantly increased the glucose uptake of HepG2 cells. Rg1 significantly reduced glycogen and lipid synthesis in HepG2 cells treated with Rg1 for 1h. However, prolonged treatment of Rg1 for 24 h increased the glycogen and lipid synthesis significantily. In adition to glycogen and lipid synthesis, we found Rg1 and CK reduced the glucose released into the medium from gluconeogenesis. It should be noted that Rg1 also reduced the level of lactate in the medium, the metabolite of anaerobic glycolysis. To investigate the signaling mechanism of these ginsenosides, the effect of Rg1 on PI3K and AMPK pathways was examined, respectively, by measuring the phosphorylation level of Akt as well as the phosphorylation level of AMPK, ACC, and LKB-1. Our results showed that PI3K pathway is involved as the phosphorylation level of Akt increased in Rg1 incubated cells. Moreover, the Rg1-induced Akt phosphorylation was completely blocked in the presence of the PI3K inhibitor, LY294002. In addition to PI3K pathway, AMPK signaling pathway is also involved in the action of ginsenosides as the phosphorylation level of AMPK and ACC was significantly increased in Rg1 treated HepG2 cells. In summary, we demonstrated that ginsenoside Rg1 significantly increased glucose uptake and inhibited glucneogenesis in HepG2 cells. In glycogen and lipid metabolism, Rg1 displayed opposite effects by decreasing or increasing glycogen and lipid synthesis upon acute- or prolonged- treatment, respectively. The signaling mechanism of Rg1 was at least partly through the activation of PI3K and AMPK pathways in HepG2 cells.

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