Home About us Contact
|
Home About us Contact | ||
|
|
||
HepG2
Kinds of HepG2 Terms modified by HepG2 Selected AbstractsEvaluation of anticancer activity of the alkaloid fraction of Alstonia scholaris (Sapthaparna) in vitro and in vivoPHYTOTHERAPY RESEARCH, Issue 2 2006Ganesh Chandra Jagetia Abstract The anticancer effect of various doses of an alkaloid fraction of Sapthaparna, Alstonia scholaris (ASERS), was studied in vitro in cultured human neoplastic cell lines (HeLa, HepG2, HL60, KB and MCF-7) and in Ehrlich ascites carcinoma bearing mice. Treatment of HeLa cells with 25 µg/mL ASERS resulted in a time dependent increase in the antineoplastic activity and the greatest activity was observed when the cells were exposed to ASERS for 24 h. However, exposure of cells to ASERS for 4 h resulted in 25% viable cells and hence this time interval was considered to be the optimum time for treatment and further studies were carried out using this time. Treatment of various cells with ASERS resulted in a concentration dependent decline in the viable cells and a nadir was reached at 200 µg/mL in all the cell lines studied. The IC50 was found to be 5.53, 25, 11.16, 10 and 29.76 µg/mL for HeLa, HePG2, HL60, KB and MCF-7 cells, respectively. Similarly, administration of ASERS, once daily for 9 consecutive days to the tumor bearing mice caused a dose dependent remission of the tumor up to 240 mg/kg body weight, where the greatest antitumor effect was observed. Since 240 mg/kg ASERS showed toxic manifestations, the next lower dose of 210 mg/kg was considered as the best effective dose, in which 20% of the animals survived up to 120 days post-tumor-cell inoculation as against no survivors in the saline treated control group. The ASERS treatment resulted in a dose dependent elevation in the median survival time (MST) and the average survival time (AST) up to 240 mg/kg ASERS and declined thereafter. The surviving animals were healthy and disease free. The effect of ASERS was better than cyclophosphamide, which was used as a positive control, where all the animals succumbed to death by 40 days and the MST and AST were 19.5 and 18.3 days, respectively. The effective dose of 210 mg of ASERS was 3/10 of the LD50 dose, which increased the MST and AST up to 54 and 49.5 days, respectively. Copyright © 2006 John Wiley & Sons, Ltd. [source] Synthesis and Biological Evaluation of Some Novel Polysubstituted Pyrimidine Derivatives as Potential Antimicrobial and Anticancer AgentsARCHIV DER PHARMAZIE, Issue 5 2009Sherif A. F. Rostom Abstract Synthesis and evaluation of the antimicrobial and cytotoxic activity of two series of polysubstituted pyrimidines comprising the thioether functionality and other pharmacophores, reported to contribute to various chemotherapeutic activities are described. All newly synthesized compounds were subjected to in-vitro antibacterial and antifungal screening. Out of the compounds tested, 18 derivatives displayed an obvious inhibitory effect on the growth of the tested Gram-positive and Gram-negative bacterial strains, with special effectiveness against the Gram-positive strains. Compounds 1, 2, 6, 7, 9, 10, 11, 21, and 24 revealed remarkable broad antibacterial spectrum profiles. Among those, compounds 1, 2, 6, 7, 9, and 24 exhibited an appreciable antifungal activity against C. albicans. Compound 2 proved to be the most active antimicrobial member identified here as it showed twice the activity of ampicillin against B. subtilis and the same activity of ampicillin against M. Luteus and P. aeruginosa together with a moderate antifungal activity. Further, eleven analogs were evaluated for their in-vitro cytotoxic potential utilizing the standard MTT assay against a panel of three human cell lines: breast adenocarcinoma MCF7, hepatocellular carcinoma HePG2, and colon carcinoma HT29. The obtained data revealed that six of the tested compounds 1, 3, 7, 12, 13, and 15 showed a variable degree of cytotoxic activity against the tested cell lines at both the LC50 and LC90 levels. Compound 7 proved to be the most active cytotoxic member in this study with special effectiveness against the colon carcinoma HT29 and breast cancer MCF7 human cell lines for LC50 and LC90. Thus, compounds 1 and 7 could be considered as possible dual antimicrobial-anticancer agents. [source] Genotoxicity of nitrosulfonic acids, nitrobenzoic acids, and nitrobenzylalcohols, pollutants commonly found in ground water near ammunition facilitiesENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2006Tamara Grummt Abstract 2-Amino-4,6-dinitrobenzoic acid (2-A-4,6-DNBA), 4-amino-2,6-dinitrobenzoic acid (4-A-2,6-DNBA), 2,4,6-trinitrobenzoic acid (2,4,6-TNBA), 2-amino-4, 6-dinitrobenzylalcohol (2-A-4,6-DNBAlc), 4-amino-2,6-dinitrobenzylalcohol (4-A-2,6-DNBAlc), 2,4-dinitrotoluol-5-sulfonic acid (2,4-DNT-5-SA), 2,4-dinitrotoluol-3-sulfonic acid (2,4-DNT-3-SA), and 2, 4-dinitrobenzoic acid (2,4-DNBA) are derivatives of nitro-explosives that have been detected in groundwater close to munitions facilities. In the present study, the genotoxicity of these compounds was evaluated in Salmonella/microsome assays (in strains TA100 and TA98, with and without S9 and in TA98NR without S9), in chromosomal aberration (CA) tests with Chinese hamster fibroblasts (V79), and in micronucleus (MN) assays with human hepatoma (HepG2) cells. All compounds except the sulfonic acids were positive in the bacterial mutagenicity tests, with 2,4,6-TNBA producing the strongest response (8023 revertants/,mol in TA98 without S9 activation). 2-A-4,6-DNBA was a direct acting mutagen in TA98, but negative in TA100. The other positive compounds were ,1,3 orders of magnitude less mutagenic than 2,4,6-TNBA in TA98 and in TA100; relatively strong effects (,50,400 revertants/,mol) were produced by the benzylacohols in the two indicator strains. With the exception of 2,4-DNBA, the mutagenic responses were lower in the nitroreductase-deficient strain TA98NR than in the parental strain. 2,4-DNBA produced a marginally positive response in the V79-cell CA assay; the other substances were devoid of activity. Only the benzoic acids were tested for MN induction in HepG2 cells, and all produced positive responses. As in the bacterial assays, the strongest effect was seen with 2,4,6-TNBA (significant induction at ,1.9 ,M). 4-A-2,6-DNBA was positive at 432 ,M; the weakest effect was observed with 2,4,-DNBA (positive at ,920 ,M). The differences in the sensitivity of the indicator cells to these agents can be explained by differences in the activities of enzymes involved in the activation of the compounds. The strong responses produced by some of the compounds in the human-derived cells suggest that environmental exposure to these breakdown products of nitro-explosives may pose a cancer risk in man. Environ. Mol. Mutagen., 2006. © 2005 Wiley-Liss, Inc. [source] Construction of Polyethyleneimine-,-cyclodextrin/pDNA Multilayer Structure for Improved In Situ Gene Transfection,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Yan Hu This study reports in situ gene delivery from gene-functionalized poly(D,L -lactic acid) (PDLLA, Mw of around 2.0,×,105,g,mol,1) films, which were constructed via layer-by-layer (LbL) assembly technique with low molecular weight polyethylenimine-,-cyclodextrin (PEI-CD) conjugate and plasmid DNA (pDNA). PEI-CD was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR), respectively. The buildup of multilayered PEI-CD/pDNA pairs onto PDLLA films was monitored with contact angle measurements and UV,Vis spectrometer, respectively. A sustained release of pDNA from multilayered films was observed for 28,h. The mechanism of in situ gene delivery on PDLLA film was investigated in this study as well. Spherical PEI-CD/pDNA complexes were formed and released following the deconstruction of multilayered films, which was confirmed by transmission electron microscopy (TEM) and gel electrophoresis, respectively. Surface mediated in situ gene transfection was achieved when culturing hepatoma G2 (HepG2) and human embryonic kidney 293 (HEK293) onto PEI-CD/pDNA multilayered films. Furthermore, PEI-CD improved the gene transfection efficiency when compared with that of PEI. Such gene-functionalized biomaterial reported here has potential application in tissue engineering and implant technology. [source] Novel genes in cell cycle control and lipid metabolism with dynamically regulated binding sites for sterol regulatory element-binding protein 1 and RNA polymerase II in HepG2 cells detected by chromatin immunoprecipitation with microarray detectionFEBS JOURNAL, Issue 7 2009Mehdi Motallebipour Sterol regulatory element-binding proteins 1 and 2 (SREBP-1 and SREBP-2) are important regulators of genes involved in cholesterol and fatty acid metabolism, but have also been implicated in the regulation of the cell cycle and have been associated with the pathogenesis of type 2 diabetes, atherosclerosis and obesity, among others. In this study, we aimed to characterize the binding sites of SREBP-1 and RNA polymerase II through chromatin immunoprecipitation and microarray analysis in 1% of the human genome, as defined by the Encyclopaedia of DNA Elements consortium, in a hepatocellular carcinoma cell line (HepG2). Our data identified novel binding sites for SREBP-1 in genes directly or indirectly involved in cholesterol metabolism, e.g. apolipoprotein C-III (APOC3). The most interesting biological findings were the binding sites for SREBP-1 in genes for host cell factor C1 (HCFC1), involved in cell cycle regulation, and for filamin A (FLNA). For RNA polymerase II, we found binding sites at classical promoters, but also in intergenic and intragenic regions. Furthermore, we found evidence of sterol-regulated binding of SREBP-1 and RNA polymerase II to HCFC1 and FLNA. From the results of this work, we infer that SREBP-1 may be involved in processes other than lipid metabolism. [source] Aldehydes release zinc from proteins.FEBS JOURNAL, Issue 18 2006A pathway from oxidative stress/lipid peroxidation to cellular functions of zinc Oxidative stress, lipid peroxidation, hyperglycemia-induced glycations and environmental exposures increase the cellular concentrations of aldehydes. A novel aspect of the molecular actions of aldehydes, e.g. acetaldehyde and acrolein, is their reaction with the cysteine ligands of zinc sites in proteins and concomitant zinc release. Stoichiometric amounts of acrolein release zinc from zinc,thiolate coordination sites in proteins such as metallothionein and alcohol dehydrogenase. Aldehydes also release zinc intracellularly in cultured human hepatoma (HepG2) cells and interfere with zinc-dependent signaling processes such as gene expression and phosphorylation. Thus both acetaldehyde and acrolein induce the expression of metallothionein and modulate protein tyrosine phosphatase activity in a zinc-dependent way. Since minute changes in the availability of cellular zinc have potent effects, zinc release is a mechanism of amplification that may account for many of the biological effects of aldehydes. The zinc-releasing activity of aldehydes establishes relationships among cellular zinc, the functions of endogenous and xenobiotic aldehydes, and redox stress, with implications for pathobiochemical and toxicologic mechanisms. [source] Proteolytic activation of internalized cholera toxin within hepatic endosomes by cathepsin DFEBS JOURNAL, Issue 17 2005Clémence Merlen We have defined the in vivo and in vitro metabolic fate of internalized cholera toxin (CT) in the endosomal apparatus of rat liver. In vivo, CT was internalized and accumulated in endosomes where it underwent degradation in a pH-dependent manner. In vitro proteolysis of CT using an endosomal lysate required an acidic pH and was sensitive to pepstatin A, an inhibitor of aspartic acid proteases. By nondenaturating immunoprecipitation, the acidic CT-degrading activity was attributed to the luminal form of endosomal cathepsin D. The rate of toxin hydrolysis using an endosomal lysate or pure cathepsin D was found to be high for native CT and free CT-B subunit, and low for free CT-A subunit. On the basis of IC50 values, competition studies revealed that CT-A and CT-B subunits share a common binding site on the cathepsin D enzyme, with native CT and free CT-B subunit displaying the highest affinity for the protease. By immunofluorescence, partial colocalization of internalized CT with cathepsin D was confirmed at early times of endocytosis in both hepatoma HepG2 and intestinal Caco-2 cells. Hydrolysates of CT generated at low pH by bovine cathepsin D displayed ADP-ribosyltransferase activity towards exogenous Gs, protein suggesting that CT cytotoxicity, at least in part, may be related to proteolytic events within endocytic vesicles. Together, these data identify the endocytic apparatus as a critical subcellular site for the accumulation and proteolytic degradation of endocytosed CT, and define endosomal cathepsin D an enzyme potentially responsible for CT cytotoxic activation. [source] Hormonal regulation of multiple promoters of the rat mitochondrial glycerol-3-phosphate dehydrogenase geneFEBS JOURNAL, Issue 14 2001Identification of a complex hormone-response element in the ubiquitous promoter B Rat mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) is regulated by multiple promoters in a tissue-specific manner. Here, we demonstrate that thyroid hormone (3,5,3,-tri-iodo- l -thyronine) and steroid hormone but not the peroxisome proliferator clofibrate and retinoic acid stimulate the activation of the ubiquitous promoter B in a receptor-dependent manner, whereas the more tissue-restricted promoters A and C are not inducible by these hormones. Thyroid hormone action is mediated by a direct repeat +4 (DR+4) hormone-response element as identified by deletion and mutation analyses of promoter B in transient transfection analyses. The DR+4 element was able to bind to an in vitro translated thyroid hormone receptor in band-shift and supershift experiments. The hormone-response element comaps with a recognition site for the transcription factor Sp1, suggesting complex regulation of this sequence element. Mutation of this Sp1-recognition site reduces the basal promoter B activity dramatically in HepG2 and HEK293 cells in transient transfection and abolishes the binding of Sp1 in band-shift experiments. As demonstrated by Western-blot experiments, administration of tri-iodothyronine to euthyroid rats increases hepatic mGPDH protein concentrations in vivo. As it has recently been reported that human mGPDH promoter B is not regulated by tri-iodothyronine, this is the first example of a differentially tri-iodothyronine-regulated orthologous gene promoter in man and rat. [source] Phytanoyl-CoA hydroxylase activity is induced by phytanic acidFEBS JOURNAL, Issue 13 2000Anna W. M. Zomer Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) is a branched-chain fatty acid present in various dietary products such as milk, cheese and fish. In patients with Refsum disease, accumulation of phytanic acid occurs due to a deficiency of phytanoyl-CoA hydroxylase, a peroxisomal enzyme containing a peroxisomal targeting signal 2. Recently, phytanoyl-CoA hydroxylase cDNA has been isolated and functional mutations have been identified. As it has been shown that phytanic acid activates the nuclear hormone receptors peroxisome proliferator-activated receptor (PPAR), and all three retinoid X receptors (RXRs), the intracellular concentration of this fatty acid should be tightly regulated. When various cell lines were grown in the presence of phytanic acid, the activity of phytanoyl-CoA hydroxylase increased up to four times, depending on the particular cell type. In one cell line, HepG2, no induction of phytanoyl-CoA hydroxylase activity was observed. After addition of phytanic acid to COS-1 cells, an increase in phytanoyl-CoA hydroxylase activity was observed within 2 h, indicating a quick cell response. No stimulation of phytanoyl-CoA hydroxylase was observed when COS-1 cells were grown in the presence of clofibric acid, 9- cis -retinoic acid or both ligands together. This indicates that the activation of phytanoyl-CoA hydroxylase is not regulated via PPAR, or RXR. However, stimulation of PPAR, and all RXRs by clofibric acid and 9- cis -retinoic acid was observed in transient transfection assays. These results suggest that the induction of phytanoyl-CoA hydroxylase by phytanic acid does not proceed via one of the nuclear hormone receptors, RXR or PPAR,. [source] The effect of modulation of , -glutamyl transpeptidase and nitric oxide synthase activity on GSH homeostasis in HepG2 cellsFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2007Inga Kwiecie Abstract High glutathione (GSH) level and elevated , -glutamyl transpeptidase (,GT) activity are hallmarks of tumor cells. Toxicity of drugs and radiation to the cells is largely dependent on the level of thiols. In the present studies, we attempted to inhibit ,GT activity in human hepatoblastoma (HepG2) cells to examine whether the administration of ,GT inhibitors, acivicin (AC) and 1,2,3,4-tetrahydroisoquinoline (TIQ) influences cell proliferation and enhances cytostatic action of doxorubicin (DOX) and cisplatin (CP) on HepG2 cells. The effects of these inhibitors were determined by 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), BrdU and lactate dehydrogenase (LDH) tests and by estimation of GSH level. Additionally, we investigated the changes in caspase-3 activity, which is a marker of apoptosis. The obtained results showed that the ,GT inhibitors introduced to the medium alone elicited cytotoxic effect, which was accompanied by an increase in GSH level in the cells. TIQ concomitantly increased caspase-3 activity. Doxorubicin and CP proved to be cytotoxic, and both inhibitors augmented this effect. As well DOX as CP radically decreased GSH levels, whereas ,GT inhibitors had diverse effects. Therefore, the obtained results confirm that ,GT inhibitors can enhance pharmacological action of DOX and CP, which may permit clinicians to decrease their doses thereby alleviating side effects. Aminoguanidine (nitric oxide synthase inhibitor) given alone was little cytotoxic to HepG2 cells, while its introduction to the medium together with DOX and CP significantly increased their cytotoxicity. Aminoguanidine on its own did not show any effect on GSH level in HepG2 cells, but markedly and significantly elevated its concentration when added in combination with CP but not with DOX. This indicates that when CP was used as a cytostatic, GSH level rose after treatment with its combination with both AC and aminoguanidine. [source] Glucagon-like peptide-1 receptor is present on human hepatocytes and has a direct role in decreasing hepatic steatosis in vitro by modulating elements of the insulin signaling pathway,HEPATOLOGY, Issue 5 2010Nitika Arora Gupta Glucagon-like peptide 1 (GLP-1) is a naturally occurring peptide secreted by the L cells of the small intestine. GLP-1 functions as an incretin and stimulates glucose-mediated insulin production by pancreatic , cells. In this study, we demonstrate that exendin-4/GLP-1 has a cognate receptor on human hepatocytes and that exendin-4 has a direct effect on the reduction of hepatic steatosis in the absence of insulin. Both glucagon-like peptide 1 receptor (GLP/R) messenger RNA and protein were detected on primary human hepatocytes, and receptor was internalized in the presence of GLP-1. Exendin-4 increased the phosphorylation of 3-phosphoinositide-dependent kinase-1 (PDK-1), AKT, and protein kinase C , (PKC-,) in HepG2 and Huh7 cells. Small interfering RNA against GLP-1R abolished the effects on PDK-1 and PKC-,. Treatment with exendin-4 quantitatively reduced triglyceride stores compared with control-treated cells. Conclusion: This is the first report that the G protein,coupled receptor GLP-1R is present on human hepatocytes. Furthermore, it appears that exendin-4 has the same beneficial effects in vitro as those seen in our previously published in vivo study in ob/ob mice, directly reducing hepatocyte steatosis. Future use for human nonalcoholic fatty liver disease, either in combination with dietary manipulation or other pharmacotherapy, may be a significant advance in treatment of this common form of liver disease. (HEPATOLOGY 2010) [source] Differentiation therapy of hepatocellular carcinoma in mice with recombinant adenovirus carrying hepatocyte nuclear factor-4, gene,HEPATOLOGY, Issue 5 2008Chuan Yin Previous studies have shown that hepatocyte nuclear factor-4, (HNF4,) is a central regulator of differentiated hepatocyte phenotype and forced expression of HNF4, could promote reversion of tumors toward a less invasive phenotype. However, the effect of HNF4, on cancer stem cells (CSCs) and the treatment of hepatocellular carcinoma (HCC) with HNF4, have not been reported. In this study, an adenovirus-mediated gene delivery system, which could efficiently transfer and express HNF4,, was generated to determine its effect on hepatoma cells (Hep3B and HepG2) in vitro and investigate the anti-tumor effect of HNF4, in mice. Our results demonstrated that forced re-expression of HNF4, induced the differentiation of hepatoma cells into hepatocytes, dramatically decreased "stemness" gene expression and the percentage of CD133+ and CD90+ cells, which are considered as cancer stem cells in HCC. Meanwhile, HNF4, reduced cell viability through inducing apparent apoptosis in Hep3B, while it induced cell cycle arrest and cellular senescence in HepG2. Moreover, infection of hepatoma cells by HNF4, abolished their tumorigenesis in mice. Most interestingly, systemic administration of adenovirus carrying the HNF4, gene protected mice from liver metastatic tumor formation, and intratumoral injection of HNF4, also displayed significant antitumor effects on transplanted tumor models. Conclusion: The striking suppression effect of HNF4, on tumorigenesis and tumor development is attained by inducing the differentiation of hepatoma cells,especially CSCs,into mature hepatocytes, suggesting that differentiation therapy with HNF4, may be an effective treatment for HCC patients. Our study also implies that differentiation therapy may present as one of the best strategies for cancer treatment through the induction of cell differentiation by key transcription factors. (HEPATOLOGY 2008.) [source] Hepatitis C virus replication is inhibited by 22,-methoxyolean-12-ene-3,, 24(4,)-diol (ME3738) through enhancing interferon-,,HEPATOLOGY, Issue 1 2008Yoichi Hiasa A derivative of soyasapogenol, 22,-methoxyolean-12-ene-3,, 24(4,)-diol (ME3738), ameliorates liver injury induced by Concanavalin A in mice. We examined whether ME3738 has independent antiviral effects against hepatitis C virus (HCV) using an established HCV replication model that expresses the full-length genotype 1a HCV complementary DNA plasmid (pT7-flHCV-Rz) under the control of a replication-defective adenoviral vector expressing T7 polymerase. Hepatocellular carcinoma (HepG2) cells, human hepatoma (Huh7) cells, or monkey kidney (CV-1) cells were transfected with pT7-flHCV-Rz, and infected with adenoviral vector expressing T7 polymerase. ME3738 or interferon-, (IFN-,) was added thereafter and then protein and RNA were harvested from the cells at 9 days after infection. HCV-positive and HCV-negative strands were measured by real-time reverse-transcription polymerase chain reaction and HCV core protein expression was measured using an enzyme-linked immunosorbent assay. The messenger RNA levels of innate antiviral response-related genes were assessed using real-time reverse-transcription polymerase chain reaction. ME3738 dose-dependently reduced HCV-RNA and core protein in hepatocyte-derived cell lines. The antiviral effect was more pronounced in HepG2 than in Huh7 cells. ME3738 increased messenger RNA levels of interferon-, (IFN-,) and of IFN-stimulated genes (2,-5, oligoadenylate synthetase, myxovirus resistance protein A [MxA]). Interferon-, knockdown by small interfering RNA abrogated the anti-HCV effect of ME3738. Moreover, the anti-HCV effects were synergistic when ME3738 was combined with IFN-,. Conclusion: ME3738 has antiviral effects against HCV. The enhancement of autocrine IFN-, suggests that ME3738 exerts antiviral action along the type I IFN pathway. This anti-HCV action by ME3738 was synergistically enhanced when combined with IFN-,. ME3738 might be a useful anti-HCV drug either with or without IFN-,. (HEPATOLOGY 2008.) [source] Expression, regulation, and function of ,V integrins in hepatocellular carcinoma: An in vivo and in vitro studyHEPATOLOGY, Issue 2 2002Mimoun Nejjari The expression of ,V integrins by neoplastic cells contributes to the promotion of local invasion and metastasis. The most characteristic extracellular ligands of ,V integrins are vitronectin and fibronectin. Hepatocytes are the main source of vitronectin, and the capacity to synthesize and secrete vitronectin is usually retained in hepatocellular carcinoma. The aim of this study was to explore the expression, regulation, and functional role of ,V integrins in hepatocellular carcinoma. We first analyzed the expression of ,V integrins and their ligands fibronectin and vitronectin in 80 cases of hepatocellular carcinoma. ,V integrin chain was detected in 44 cases and vitronectin in 50. Twenty-four of the 44 ,V-positive tumors contained large amounts of vitronectin. These cases presented more frequently with adverse histoprognostic factors, including infiltrative growth pattern (62.5%), lack of capsule (71%), presence of capsular invasion (57%), and satellite nodules (50%). We then used HepG2 and Hep3B cell lines as in vitro models to study ,V integrin regulation and function. HepG2 and Hep3B cells expressed ,V integrin chain and used ,V,1 and ,V,5 for adhesion and migration on vitronectin. Tumor necrosis factor (TNF) , and transforming growth factor (TGF) , significantly increased the expression levels of ,V integrins and stimulated the adhesion and migration of both HepG2 and Hep3B cell lines on vitronectin. The effects of growth factors on cell adhesion and migration were reproduced by incubation with conditioned medium from rat liver myofibroblasts. In conclusion, our results support the existence of an ,V integrin/vitronectin connection in hepatocellular carcinoma and suggest that this connection may be an adverse prognostic factor. [source] Increase in de novo HBV DNA integrations in response to oxidative DNA damage or inhibition of poly(ADP-ribosyl)ationHEPATOLOGY, Issue 1 2002Maura Dandri Chronic infection with hepatitis B virus (HBV) is associated with an increased risk for the development of cirrhosis and hepatocellular carcinoma (HCC). Although clonal HBV DNA integrations are detected in nearly all HCCs the role of these integrations in hepatocarcinogenesis is poorly understood. We have used a cloning protocol that allows studying the frequency and the natural history of HBV DNA integrations in cell culture. Southern blot analysis of the genomic DNA of HepG2 2.2.15 subclones, which replicate HBV, enabled us to detect new HBV DNA integrations in approximately 10% of the HepG 2.2.15 subclones over 4 rounds of sequential subcloning, whereas no loss of any preexisting HBV DNA integrations was observed. Treatments of HepG2 cells with H2O2, designed to increase DNA damage, increased the frequency of HBV integrations to approximately 50% of the subclones and treatments designed to inhibit DNA repair, by inhibiting Poly(ADP-ribosyl)ation, also increased the frequency of HBV integration to 50%. These findings suggest that DNA strand breaks induced by oxidative stress during persistent HBV infection in humans may increase HBV DNA integration events, whereas PARP-1 activity may function to limit the occurrence of de novo HBV DNA integrations. [source] Mechanisms of cell death induced by suicide genes encoding purine nucleoside phosphorylase and thymidine kinase in human hepatocellular carcinoma cells in vitroHEPATOLOGY, Issue 3 2001Tim U. Krohne For gene therapy of hepatocellular carcinoma (HCC), the Escherichia coli purine nucleoside phosphorylase (PNP)/fludarabine suicide gene system may be more useful than the herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system as a result of a stronger bystander effect. To analyze the molecular mechanisms involved in PNP/fludarabine-mediated cell death in human HCC cells in comparison with HSV-tk/GCV, we transduced human HCC cells of the cell lines, HepG2 and Hep3B, with PNP or HSV-tk using adenoviral vectors, followed by prodrug incubation. Both systems predominantly induced apoptosis in HepG2 and Hep3B cells. PNP/fludarabine induced strong p53 accumulation and a more rapid onset of apoptosis in p53-positive HepG2 cells as compared with p53-negative Hep3B cells, but efficiency of tumor cell killing was similar in both cell lines. In contrast, HSV-tk/GCV,induced apoptosis was reduced in p53-negative Hep3B cells as compared with p53-positive HepG2 cells. HSV-tk/GCV, but not PNP/fludarabine, caused up-regulation of Fas in p53-positive HepG2 cells and of Fas ligand (FasL) in both HCC cell lines. These results demonstrate cell line,specific differences in response to treatment with PNP/fludarabine and HSV-tk/GCV, respectively, and indicate that PNP/fludarabine may be superior to HSV-tk/GCV for the treatment of human HCC because of its independence from p53 and the Fas/FasL system. (HEPATOLOGY 2001;34:511-518.) [source] Expression and role of Bcl-xL in human hepatocellular carcinomasHEPATOLOGY, Issue 1 2001Tetsuo Takehara Transformed hepatocytes survive various apoptotic insults during their growth in vivo. However, molecular mechanisms that inhibit apoptosis and support their survival are not well understood. In this study, we investigated the expression and role of Bcl-xL, an antiapoptotic member of the Bcl-2 family, in human hepatocellular carcinoma (HCC). The Bcl-xL protein was expressed in HepG2, Hep3B, and Huh7 human hepatoma cell lines at high levels, but none of these cells expressed Bcl-2. Down-modulation of Bcl-xL by antisense oligonucleotide activated apoptosis in HepG2 cells in response to cellular stresses induced by staurosporine treatment or by serum starvation. Ectopic expression of transcriptionally active p53 alone was not sufficient for the activation of apoptosis in p53 -null Hep3B cells, but apoptosis was induced when endogenous Bcl-xL was simultaneously inhibited by antisense oligonucleotide in these cells. Bcl-xL was expressed in all 20 surgically resected human HCC tissues when examined by Western blot analysis and immunohistochemistry, and levels of its expression were higher in a subset of HCC tissues than those of adjacent nontumor liver tissues or normal livers. We conclude that Bcl-xL expressed in human HCC cells inhibits apoptosis produced by various cellular stresses, such as staurosporine treatment, serum starvation, and p53 activation, and may play an important role in their survival. [source] Hepatocyte growth factor promotes cell survival from Fas-mediated cell death in hepatocellular carcinoma cells via Akt activation and Fas-death,inducing signaling complex suppressionHEPATOLOGY, Issue 4 2000Atsushi Suzuki The Akt/PI-3 kinase pathway is a system essential for cell survival. In the current study, we showed that hepatocyte growth factor (HGF) activates the Akt/PI-3 kinase pathway to suppress Fas-mediated cell death in human hepatocellular carcinoma (HCC; 3 lines; SK-Hep1, HLE, and Chang Liver cell lines), hepatoblastoma (1 line; HepG2), and embryonic hepatocyte (1 line; WRL). Five tested cell lines showed the resistance to Fas-mediated cell death by the pretreatment of HGF. This HGF-induced cell survival was suppressed by wortmannin (Akt/PI-3 kinase pathway inhibitor), suggesting an involvement of Akt. When cells were pretreated with HGF, Fas-mediated cell death was suppressed, followed by Akt phosphorylation at Ser473. Fas-death,inducing signaling complex (DISC) formation, especially FADD and caspase 8 interaction, was suppressed by HGF and the suppression of the Akt/PI-3 kinase pathway by transient expression of PTEN, resulting in acquisition of Fas-DISC formation and Fas-mediated cell death in HGF-treated cells. We suggest that HGF promotes cell survival in hepatocyte-derived cell lines (HCC, hepatoblastoma, and embryonic hepatocyte) from Fas-mediated cell death via Fas-DISC suppression as a result of Akt activation. [source] Silencing MAT2A gene by RNA interference inhibited cell growth and induced apoptosis in human hepatoma cellsHEPATOLOGY RESEARCH, Issue 5 2007Quanyan Liu Aims:, A switch in gene expression from MAT1A to MAT2A was found in liver cancer, suggesting that MAT2A plays an important role in facilitating cancer growth. MAT2A is an interesting target for antineoplastic therapy. The molecular mechanisms of silencing MAT2A by RNA interference inhibited cell growth and induced apoptosis in hepatoma cells was studied. Methods:, We investigated the effects of MAT2A on S-adenosyl-methionine (SAM) production, cell growth and apoptotic cell death in hepatoma cell lines (Bel-7402, HepG2, and Hep3B) using an RNA interference approach. Results:, The treatment of three hepatoma cell lines with small interfering RNA (siRNA) targeting to the MAT2A gene resulted in reducing the MAT II activity, facilitating SAM production, increasing SAM : SAH ratio, inhibiting cell growth and inducing cell apoptosis in hepatoma cells. In addition, silencing MAT2A gene resulted in the stimulation of MAT1A mRNA production, which was blocked by 3-deazaadenosine and l -ethionine, but not d -ethionine, suggesting that such effect was specific and mediated by upregulation of SAM level and SAM : S-adenosylethionine (SAH) ratio. Conclusion:, Silencing MAT2A by sequence-specific small interfering RNA caused a switch of MAT gene expression from MAT2A to MAT1A, which led the content of SAM to change to a higher steady-state level that resulted in the inhibition of cell growth and the induction of apoptotic cell death in human hepatoma cells. These results also suggested that MAT2A may hold potential as a new target for liver cancer gene therapy. [source] Interferon alpha receptors are important for antiproliferative effect of interferon-, against human hepatocellular carcinoma cellsHEPATOLOGY RESEARCH, Issue 1 2007Bazarragchaa Damdinsuren Aim:, Interferon (IFN)-, is a promising drug for the prevention and treatment of hepatocellular carcinoma (HCC). We reported that responders to IFN-,/5-fluorouracil combination therapy expressed higher IFN alpha receptor (IFNAR)2 in tumor. Herein we studied involvement of IFNARs in response to IFN-, in HCC cells. Methods:, IFN-, sensitivity and expression of IFNARs were studied in six HCC cell lines (HuH7, PLC/PRF/5, HLE, HLF, HepG2, Hep3B) using growth-inhibitory and RT-PCR, Western blot assays. Short interfering RNAs (SiRNAs) against IFNAR1 and 2 were used to analyze the role of the IFNARs in IFN-,'s effect and signal transduction. Results:, The expressions of IFNAR1 and 2c mRNAs were higher in PLC/PRF/5 cells than those in other cell lines, and PLC/PRF/5 cells expressed abundant IFNAR2c on their cell membrane. When we examined the sensitivity of the HCC cell lines to the growth-inhibitory effect of IFN-,, PLC/PRF/5 exhibited a significant response, while the other cells were much more resistant. Knockdown of either IFNAR1 or 2 using siRNAs suppressed the IFN-,'s signal transduction (2.5-fold), and decreased the growth-inhibitory effect (down by 69.9% and 67.3%). Conclusion:, The results suggest that the expression of IFNAR1 and IFNAR2c independently are important for the antiproliferative effect of IFN-, in HCC cells. [source] Allelic imbalance (AI) identifies novel tissue-specific cis- regulatory variation for human UGT2B15,HUMAN MUTATION, Issue 1 2010Chang Sun Abstract Allelic imbalance (AI) is a powerful tool to identify cis -regulatory variation for gene expression. UGT2B15 is an important enzyme involved in the metabolism of multiple endobiotics and xenobiotics. In this study, we measured the relative expression of two alleles at this gene by using SNP rs1902023:G>T. An excess of the G over the T allele was consistently observed in liver (P<0.001), but not in breast (P=0.06) samples, suggesting that SNPs in strong linkage disequilibrium with G253T regulate UGT2B15 expression in liver. Seven such SNPs were identified by resequencing the promoter and exon 1, which define two distinct haplotypes. Reporter gene assays confirmed that one haplotype displayed ,20% higher promoter activity compared to the other major haplotype in liver HepG2 (P<0.001), but not in breast MCF-7 (P=0.540) cells. Reporter gene assays with additional constructs pointed to rs34010522:G>T and rs35513228:C>T as the cis -regulatory variants; both SNPs were also evaluated in LNCaP and Caco-2 cells. By ChIP, we showed that the transcription factor Nrf2 binds to the region spanning rs34010522:G>T in all four cell lines. Our results provide a good example for how AI can be used to identify cis -regulatory variation and gain insights into the tissue specific regulation of gene expression. Hum Mutat 30:1,9, 2009. © 2009 Wiley-Liss, Inc. [source] Antitumor effects of a recombinant pseudotype baculovirus expressing Apoptin in vitro and in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Yongfei Pan Abstract Apoptin, a chicken anemia virus-derived, p53-independent, bcl-2-insenstive apoptotic protein with the ability to specifically induce apoptosis in tumor or transformed cells, is a promising tool for cancer gene therapy. In this study, pseudotype baculovirus, a recently developed alternative gene delivery system, was used as a vector to express Apoptin. The resultant recombinant baculovirus (BV-Apoptin) efficiently expressed the Apoptin protein and induced apoptosis in HepG2 and H22 cells. Studies in vivo showed that intratumoral injection of BV-Apoptin into a xenogeneic tumor (derived from H22 murine hepatoma cells in C57BL/6 mice) significantly suppressed tumor growth, and significantly prolonged the survival of tumor-bearing mice compared to a control pseudotype baculovirus that expressed EGFP. Taken together, these results suggest that Apoptin, expressed from the pseudotype baculovirus vector, has the potential to become a therapeutic agent for the treatment of solid tumors. [source] Lack of functional erythropoietin receptors of cancer cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 5 2008Magdalena Laugsch Abstract Erythropoietin (Epo) therapy reduces red cell transfusion requirements and improves the quality of life of anemic cancer patients receiving chemotherapy. However, there is concern that Epo may promote tumor growth. We investigated by real-time RT-PCR, immunofluorescence microscopy, Western blotting and cell growth analysis whether human cancer cell lines (SH-SY5Y, MCF7, HepG2, U2-OS, HeLa, HEK293T, RCC4, HCT116, 7860wt and SW480) possess functional Epo receptors (EpoR). We detected EpoR mRNA in all cell lines. Neither hypoxia nor Epo treatment altered the level of EpoR mRNA expression. Four commonly used commercial antibodies proved to be unsuitable for immunoblot procedures because they cross-reacted with several proteins unrelated with EpoR. Depending on the antibody used, EpoR was localized to the plasma membrane, the cytoplasm or the nucleus. Experiments with small interfering RNA showed that EpoR protein was not expressed by the tumor cells except by UT7/Epo leukemia cells, which served as an EpoR positive control line, and by cells transfected with the human EpoR gene. Apart from UT7/Epo, none of the tumor cell lines responded to Epo treatment with phosphorylation of signaling molecules or with cell proliferation. © 2007 Wiley-Liss, Inc. [source] Antitumor effects of a recombinant fowlpox virus expressing Apoptin in vivo and in vitroINTERNATIONAL JOURNAL OF CANCER, Issue 12 2006Xiao Li Abstract Apoptin is a chicken anemia virus-derived, p53-independent, bcl-2-insensitive apoptotic protein with the ability to specifically induce apoptosis in tumor cells. To explore the use of the Apoptin gene in cancer gene therapy, we constructed a recombinant fowlpox virus expressing the Apoptin protein (vFV- Apoptin) and compared the tumor-killing activity of the recombinant virus with that of wild-type fowlpox virus in the human hepatoma cell line HepG2. We found that although cells were somewhat resistant to the basal cytotoxic effect of wild-type fowlpox virus, infection with vFV- Apoptin caused a pronounced, additional cytotoxic effect. Furthermore, cell death and disruption of tumor integrity were apparent in the vFV- Apoptin -infected cells. We also tested whether fowlpox virus-mediated expression of Apoptin in tumor cells could stimulate an antitumor effect by injecting aggressive subcutaneous tumors derived from H22 mouse hepatoma cells in C57BL/6 mice with vFV- Apoptin. We found that fowlpox virus-mediated intratumoral expression of the Apoptin gene can induce protective and therapeutic antitumor effects and significantly increase survival. Taken together, these data indicate that infection of tumors with fowlpox virus expressing Apoptin inhibits tumor growth, induces apoptosis and may be an effective cancer treatment. © 2006 Wiley-Liss, Inc. [source] TLRs antiviral effect on hepatitis B virus in HepG2 cellsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2008C. Xia Abstract Aims:, A hepatoma cell line, HepG2, was used as a model system to detect Toll-like receptor (TLR) expression in hepatocytes and examine the antiviral effect on hepatitis B virus (HBV). Methods and Results:, Toll-like receptor expression was detected in HepG2 cells by RT-PCR. The TLRs, which were strongly expressed in HepG2 cells, were stimulated with specific ligands. Interferon (IFN) response was evaluated poststimulation with Western blotting for signal transduction and activators of transcription-1. Furthermore, HepG2 cells were transiently transfected with wild-type HBV 1·3-fold over-length plasmid and treated with specific ligands at indicated times. Replication of HBV DNA, transcription of HBV RNA intermediate and expression of HBV antigens were respectively detected by Southern blotting, real time PCR, ELISA and Western blotting. Activation of different TLRs induced antiviral effects on HBV to varying degrees. Conclusions:, The TLRs, which were strongly expressed in HepG2 cells, could be stimulated with specific ligands. Activation of TLRs induced apparent production of antiviral cytokines such as IFN-,/, and inhibited HBV lifecycle in the hepatocyte cell model. Significance and Impact of the Study:, Expression of TLRs in hepatocytes may be related to local immunity of liver and participate in the outcome of viral hepatitis. [source] In vitro evaluation of the chemoprotective action mechanisms of leontopodic acid against aflatoxin B1 and deoxynivalenol-induced cell damageJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2009Stefano Costa Abstract Several in vitro studies showed that free radical scavengers possess chemopreventive properties against mycotoxin-induced cell damage which are at least partially associated with the induction of phase II detoxifying enzymes and antioxidant enzymes like glutathione S -transferase (GST) and glutathione peroxidase (GPx). The aim of this project was to study the chemopreventive effects of leontopodic acid (LA), a potent natural occurring free radical scavenger isolated from the aerial parts of Leontopodium alpinum. Different mycotoxins were evaluated in two different cell lines on the basis of their specific toxicity: aflatoxin B1 (AFB1) on HepG2 cells and deoxynivalenol (DON) on U937 cells. Cell viability and reactive oxygen species concentration were determined, and the effects of pre-treatment with LA on these parameters were investigated together with the GST and GPx activity as well as the concentration of reduced glutathione. The results show that LA protects U937 cells from DON-induced cell damage but not HepG2 cells from AFB1. Moreover LA is able to enhance GPx activity in U937, but not GST activity in HepG2. We hypothesize that the increase in detoxifying enzymes is probably the main mechanism of antioxidant mediated chemoprevention. Copyright © 2008 John Wiley & Sons, Ltd. [source] Influence of the metabolic properties of human cells on the kinetic of formation of the major benzo[a]pyrene DNA adductsJOURNAL OF APPLIED TOXICOLOGY, Issue 5 2008Caroline Marie Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants. Some of them, including benzo[a]pyrene (B[a]P), are tumorigenic due to their ability to generate DNA adducts. In order to define potential biomarkers of B[a]P exposure, the aim of the study was to identify the major stable DNA adducts in B[a]P-treated human cells. The role played by cellular metabolism on the nature and frequency of the DNA lesions was investigated using keratinocytes (HaCat) and actively metabolizing hepatocytes (HepG2) cell lines. Quantification of DNA damage was carried out by HPLC coupled to tandem mass spectrometry, a sensitive method making possible the selective detection of the different potential stable DNA adducts of B[a]P. These include two adducts of the 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) pathway and three adducts of the radical cation pathway. The results indicate that incubation of cells with B[a]P induces almost exclusively the formation of BPDE DNA adducts on purine bases. The amount of DNA adducts generated in hepatocytes was found to be two orders of magnitude higher than that measured in keratinocytes. Interestingly, the level of the DNA adducts produced in the cells incubated with (±)- anti -BPDE was similar in the two cell lines, indicating that the difference observed upon incubation with B[a]P could be attributed to different kinetics of B[a]P metabolism. The repair rate of BPDE DNA adducts was identical in the two cell lines with a half-life estimated to be around 20 h. These data support the use of the stable BPDE DNA adducts, as relevant biomarkers of exposure to B[a]P. Copyright © 2007 John Wiley & Sons, Ltd. [source] Sulforaphane and its analogues inhibit CYP1A1 and CYP1A2 activity induced by benzo[a]pyreneJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2009Katarzyna Skupinska Abstract CYP1A1 and CYP1A2 enzymes metabolize polycyclic aromatic hydrocarbons (PAHs) to the reactive oxyderivatives. PAHs can induce the activity of both enzymes, which increases its conversion and enhances risk of carcinogenesis. Thus, the inhibition of CYP enzymes is recognized as a cancer chemoprevention strategy. A well-known group of chemopreventive agents is isothiocyanates, which occur naturally in Brassica vegetables. In this paper, a naturally occurring sulforaphane and its two synthetic analogues isothiocyanate-2-oxohexyl and alyssin were investigated. The aim of the study was to determine whether the differences in the isothiocyanate structure change its ability to inhibit CYP1A1 and CYP1A2 activity induced by benzo[a]pyrene in HepG2 and Mcf7 cells. Also a mechanistic study was performed including isothiocyanates' influence on CYP1A1 and CYP1A2 catalytic activity, enzymatic protein level, and AhR translocation. It was shown that both enzymes were significantly induced by benzo[a]pyrene, and isothiocyanates were capable of decreasing the induced activity. The inhibitory properties depend on the types of isothiocyanate and enzyme. In general, CYP1A2 was altered in the more meaningful way than CYP1A1 by isothiocyanates. Sulforaphane exhibited weak inhibitory properties, whereas both analogues were capable of inhibiting BaP-induced activity with the similar efficacy. The mechanistic study revealed that analogues decreased the CYP1A2 activity via the protein-level reduction and CYP1A1 directly. The results indicate that isothiocyanates can be considered as potent chemopreventive substances and the change in the sulforaphane structure increases its chemopreventive potency. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:18,28, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20259 [source] Effects of nickel poisoning on expression pattern of the 72/73 and 94 kDa stress proteins in rat organs and in the COS-7, HepG2, and A549 cell linesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2005N. Hfaiedh Abstract The present study deals with the effects of Ni on the expression level of three stress proteins, namely, the cytosolic HSP72 and HSP73, and the reticulum-associated GRP94. Experiments were carried out on "Wistar" female rats daily injected with 4 mg NiCl2 per kg body weight for 1, 3, 5, and 10 days. Another set of experiments were carried out using cell lines, derived from the monkey kidney (COS-7), and from human tumors of the lung (A549) and liver (HepG2). Cells were cultured for 4 days in the permanent presence of 100, 200, or 400 µM NiCl2. In control rats, stress proteins pattern was found to be tissue specific: two protein bands of 96 and 94 kDa were immunodetected with the anti-GRP94 antibody in kidney and liver extracts, whereas only the 96 kDa band was present in ovary extracts. HSP73 was present in kidney, liver, and ovary whereas HSP72 was only found in kidney. In kidney of nickel-treated animals, HSP73 and the 96 kDa proteins were overexpressed whereas HSP72 was strongly down regulated. No such effect was observed in liver or ovary. Similarly, in nickel-treated cell lines, HSP72 was downregulated and GRP94 (96 kDa protein) was overexpressed. HSP73 expression appeared moderately increased in A549 cells but decreased in COS-7 cells. Because long-term caloric restriction was reported to reduce free radical generation in cells, the effect of 1 month food restriction (50%) was tested in rats as a possible way to lower oxidative damages induced by Ni. No significant effect on HSP expression was observed. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:12,18, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20056 [source] Reduction of PKC, decreases cell proliferation, migration, and invasion of human malignant hepatocellular carcinomaJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2008Trang-Tiau Wu Abstract Protein kinase C (PKC) superfamily play key regulatory roles on the development of cancer. However, the exact role of these enzymes in human hepatocellular carcinoma (HCC) has not been well established. Using the RT-PCR and Western blotting to analyze the levels of PKC isoforms mRNA and protein in the five different differentiated hepatoma cell lines, we found that PKC, was highly expressed in the poor-differentiated HCC cell lines (SK-Hep-1 and HA22T/VGH) as compared with that in the well-differentiated HCC cell lines (PLC/PRF/5, Hep3B, and HepG2). When treated with PKC, antisense oligonucleotides (ODN), both HA22T/VGH and SK-Hep-1 cells lines showed the reduction of PKC, expression, as well as a deceleration in the growth rate and in the level of cyclin D1, but the increase in the levels of p53 and p21WAF1/CIP1. Moreover, the reduction of PKC, expression also inhibited the migratory and invasive potential of both HA22T/VGH and SK-Hep-1 cells lines, and revealed a down-regulation of several migration/invasion-related genes (MMP-1, u-PA, u-PAR, and FAK). These phenomenon were also confirmed by DNA-based small interfering RNA (siRNA) PKC, and PKC,/, specific inhibitor Go6976. Thus, the results indicated that PKC, may be associated with regulation of cell proliferation/migration/invasion in human poorly differentiated HCC cells, suggesting a role for the PKC, in the malignant progression of human HCC. J. Cell. Biochem. 103: 9,20, 2008. © 2007 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||