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This study was to analyze the effect of triptolide (TPL) on proliferation, apoptosis, and the relationship between TPL and the Janus kinase/signal transducer and activator of transcription signaling pathway in hepatoma cells. HepG2 cell line was selected as the experimental object and divided into control, low-dose TPL, medium-dose TPL, and high-dose TPL group. The control group did not receive any drug treatment, while the low, medium, and high-dose groups were treated with TPL at concentrations of 0.02, 0.05, and 0.10 μM, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, flow cytometry, and western blot were used to detach the TPL effect and mechanism. The cell proliferation inhibition rate in each dose group of TPL was lower than that in the control group, and the inhibition rate of cell proliferation increased with the increase of TPL dose (P < 0.05). The apoptosis rate of TPL in each dose group was higher than that in the control group, and the apoptosis rate increased with the increase of TPL dose (P < 0.05). The expression of phosphorylated Janus kinase 1 (p-JAK1) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) protein in cells of each dose group of TPL was lower than that in the control group, and the expression of p-JAK1 and p-STAT3 protein decreased with the increase of TPL dose (P < 0.05). The apoptosis rate of 10 ng/mL transforming growth factor-beta + high-dose group was reduced than that in the high-dose group, and the expression of p-JAK1 and p-STAT3 protein was higher than that in the high-dose group (P < 0.05). The activity of B-cell lymphoma/leukemia-2-associated X protein (Bax) protein and cysteine aspartic acid protease (Caspase)-3/9 in TPL cells at each dose was raised than that in the control group, and the expression of B-cell lymphoma/leukemia-2 (Bcl-2) protein was decreased than that in the control group. With the increase of TPL dose, the activity of Bax protein and Caspase-3/9 increased, and the Bcl-2 protein decreased (P < 0.05). As an anti-liver cancer agent, TPL inhibits the proliferation of hepatocellular carcinoma cells and promotes apoptosis. The mechanism may involve inhibiting Janus kinase 1/signal transducer and activator of transcription 3 pathway and activation of apoptosis-related pathways. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of progesterone receptor membrane component 1 (PGRMC1) mediated autophagy on the sensitivity of liver cancer cells to 125I particles irradiation. Methods Hepatoma cell lines Huh7 and LM3 were exposed to different doses (0, 2, 4, 6 and 8 Gy) of 125I particles, and cell autophagy was observed by transmission electron microscopy (TEM). Then, autophagy inhibitor chloroquine (CQ), agonist rapamycin (Rapa), and PGRMC1 inhibitor AG-205 were used respectively to verify that PGRMC1-mediated autophagy plays a key role in the sensitivity of hepatocellular carcinoma cells to 125I particle irradiation. Cell proliferation, colony formation and apoptosis were detected by CCK-8 assay, clonal formation test and flow cytometry, respectively. The expression levels of PGRMC1, microtubule-associated protein light chain 3-Ⅰ (LC3-Ⅰ), LC3-Ⅱ and p62 were detected by Western blotting. Results Different doses of 125I particles irradiation significantly decreased the proliferation and clonogenesis of Huh7 and LM3 cells (P < 0.05), and increased the apoptotic cells (P < 0.01), in a dose-dependent manner. Compared with the 0 Gy group, the ratio of LC3-Ⅱ/ LC3-Ⅰ in Huh7 and LM3 cells was obviously increased, and the expression of p62 was significantly down-regulated in the 6 Gy group. The proliferation capacity and clonal formation ability of Huh7 and LM3 cells were decreased significantly, and their apoptotic cells were increased notably in the 6 Gy+CQ group than the 6 Gy group, while the above results were on the contrary in the 6 Gy+Rapa group. The 6 Gy+AG205 group had notably decreased LC3-Ⅱ/LC3-Ⅰ ratio in the Huh7 and LM3 cells, up-regulated p62 expression, reduced cell proliferation capacity and clone formation ability, and enhanced cell apoptosis when compared with the 6 Gy group, and the above results of the 6 Gy+PGRMC1 group were opposite. Conclusion Increment of PGRMC1 induced by 125I irradiation can promote autophagy, increase the proliferation and clonogenesis, and reduce the apoptosis in hepatocellular carcinoma cells.

To examine the impact of p21-activated kinase 1 on the growth, migration, apoptosis and invasion of hepatocellular carcinoma cells and its related mechanism. Hep38 was selected and divided into blank group, transfection control group and transfection group. The blank group was not given any treatment, the transfection control group was transfected with universal nonsense sequence, and the transfection group was given p21-activated kinases 1 sequence. The proliferation ability of cell counting kit-8 cells was compared by cell proliferation assay at different points in time after transfection. The cell cycle and apoptosis rate were detected by flow cytometry, the ability of cell migration was detected by scratch test, the p21-activated kinases 1/extracellular signal-regulated kinase pathwayrelated protein expression was found using the Western blot method, and the invasiveness of the cells in each group was assessed using the Transwell invasion test. The ability of cell proliferation in the transfection group was reduced than the blank group and the transfection control group at each time point. The proportion of cells in G1 phase in transfection group was reduced than blank group and transfection control group, while the proportion of G2/M phase in transfection group was higher than blank group and transfection control group. The apoptosis rate in the transfection group was higher than the blank group and the transfection control group. After 72 h of transfection, the number of invasive cells in the transfection group was reduced than the blank group and the transfection control group. After 24 h and 48 h of transfection, the cell migration ability of the transfection group was reduced than that blank group and the transfection control group. The expression of phosphorylated-p21-activated kinases 1 and phosphorylated-extracellular signal-regulated kinase 1/2 protein in the transfection group was reduced than the blank group and the transfection control group. Silencing the expression of the p21-activated kinases 1 gene can hinder hepatoma cell motility and invasion, decrease hepatoma cell proliferation, and cause apoptosis by causing cell arrest in the G2 shock M phase. Its suppression of the expression of proteins connected to the p21-activated kinases 1/extracellular signal-regulated kinase pathway could be the mechanism. [ABSTRACT FROM AUTHOR]

Osthole is a natural coumarin substance that has an inhibitory effect on hepatic cancer, but its radiosensitization effect on hepatoma cells has not been reported. This study aimed to investigate the effect of osthole. Human HCC-LM3 and SK-Hep-1 hepatoma cells were used and treated with or without osthole, irradiation, or their combination; the cell survival, migration, colony formation, DNA damage repair, intracellular lactic acid content, and glycolysis-related glycogen synthase kinase-3β (GSK-3β), p-GSK-3β, AMP-activated protein kinase (AMPK), p-AMPK, mammalian target of rapamycin (mTOR), p-mTOR, glucose transporter-1 (GLUT-1), GLUT-3, and pyruvate kinase isozyme type M2 (PKM2) protein expressions were determined. Compared with the irradiation group, the osthole plus irradiation group could further decrease the survival rate, migration, colony formation, and DNA damage repair of both hepatoma cells, indicating a synergistic effect of the combination treatment. Moreover, the combination of osthole and irradiation could decrease the content of intracellular lactic acid, ratios of intracellular p-GSK-3β/GSK-3β and p-mTOR/mTOR proteins, and expressions of intracellular GLUT-1/3 and PKM2 proteins, and increase the ratio of intracellular p-AMPK/AMPK proteins. Osthole can increase the radiosensitivity of hepatoma cells, and its radiosensitization mechanisms may be related to glycolytic inhibition by attenuating the GSK-3β/AMPK/mTOR pathway. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) begins with lipid accumulation within hepatocytes, but the relative contributions of different macronutrients is still unclear. We investigated the impact of fatty acids, glucose and fructose on lipid accumulation in primary human hepatocytes (PHH) and three different cell lines: HepG2 (human hepatoblastoma–derived cell line), Huh7 (human hepatocellular carcinoma cell line) and McA-RH7777 (McA, rat hepatocellular carcinoma cell line). Cells were treated for 48 h with fatty acids (0 or 200 μM), glucose (5 mM or 11 mM) and fructose (0 mM, 2 mM or 8 mM). Lipid accumulation was measured via Nile Red staining. All cell types accumulated lipid in response to fatty acids (p < 0.001). PHH and McA, but not HepG2 or Huh7 cells, accumulated more lipid with 11 mM glucose plus fatty acids (p = 0.004, fatty acid × glucose interaction, for both), but only PHH increased lipid accumulation in response to fructose (p < 0.001). Considerable variation was observed between PHH cells from different individuals. Lipid accumulation in PHH was increased by insulin (p = 0.003) with inter-individual variability. Similarly, insulin increased lipid accumulation in both HepG2 and McA cells, with a bigger response in McA in the presence of fatty acids (p < 0.001 for fatty acid × insulin). McA were more insulin sensitive than either HepG2 or Huh7 cells in terms of AKT phosphorylation (p < 0.001 insulin × cell type interaction). Hence, glucose and fructose can contribute to the accumulation of lipid in PHH with considerable inter-individual variation, but hepatoma cell lines are not good models of PHH. [ABSTRACT FROM AUTHOR]

Hepatotoma is the leading type of primary liver cancer in adults and third cause of death in the world. Hydroxytyrosol is a natural phenol existing in olive (Olea europaea L.). Hydroxytyrosol is the chief ingredient of olive oil, which was early deemed to be the most robust antioxidant in olive oil. Hydroxytyrosol is known to inhibit various types of cancer by different methods. This study was aimed to delineate the action of hydroxytyrosol on viability and [Ca2+]i in HepG2 hepatoma cells. Fura-2 was used to detect [Ca2+]i, and WST-1 assays were applied to explore cell cytotoxicity. Hydroxytyrosol elicited [Ca2+]i raises. Eliminating external Ca2+ diminished the Ca2+ signal by 30%. Hydroxytyrosol-evoked Ca2+ influx was diminished by 20% by three inhibitors of store-operated Ca2+ channels and by a protein kinase C activator and an inhibitor. In the absence of Ca2+, thapsigargin eradicated hydroxytyrosol-provoked [Ca2+]i raises. Suppression of phospholipase C (PLC) with U73122, a PLC inhibitor, did not inhibit hydroxytyrosol-elicited [Ca2+]i raises. Hydroxytyrosol reduced cell viability. This cytotoxic action was not reversed by preincubation with BAPTA/AM, a cytosolic Ca2+ binder. In sum, in HepG2 hepatoma cells, hydroxytyrosol elicited [Ca2+]i raises by provoking PLC-unrelated discharge of Ca2+ from ER and Ca2+ influx through PKC-sensitive store-operated Ca2+ entry. In addition, hydroxytyrosol elicited Ca2+-dissociated cytotoxicity.

We designed three cholesterol-modified carboxylated pullulan (CHSP) polymers modified with different degrees of substitution (DS). Nuclear magnetic resonance (NMR) was used to characterize CHSP polymer and calculate the DS, which were 2.12%, 4.36% and 6.05% for CHSP1, CHSP2 and CHSP3. The particle sizes identified by dynamic light scattering (DLS) were approximately 229.4 nm, 185.1 nm and 178.0 nm.The mitoxantrone (MTO) loadings of three nanoparticles were 5.28%, 6.71% and 7.68%. At pH 6.8, 72 hours later, the drug release rates were 95.42%, 86.88%, and 80.16%. In the weakly acidic environment, the drug release rate was significantly accelerated but still showed three types of nanoparticles and hydrophobic substitution degree-related slow release characteristics. In the cytotoxicity experiments, it was found that the inhibitory effect of the three nanoparticles on hepatoma cells is related to the degree of hydrophobic substitution, and the nanoparticles with the lowest hydrophobic substitution degree have the strongest inhibitory effect. [ABSTRACT FROM AUTHOR]

To explore the effect of esomeprazole on the biological characteristics of hepatoma cells by regulating protein kinase B/forkhead box O3 pathway. Hepatoma cell lines were cultured and sub cultured and divided into model group, low dose group and high dose group. The changes of proliferation, colony formation and apoptosis of hepatoma cells in each group and the expression levels of proliferation, apoptosis related proteins and protein kinase B/forkhead box O3 pathway related proteins were detected. Esomeprazole inhibited tumor cells in a time and dose-dependent manner and the difference was statistically significant (p<0.05). With the increase of drug dose, the number of liver cancer cell colony formation decreased gradually and the difference was statistically significant (p<0.05). Esomeprazole induced apoptosis of tumor cells in a time and dose-dependent manner and the difference was statistically significant (p<0.05). Compared with the model group, the expression levels of cyclin-dependent kinase 1, cyclin-dependent kinase 2, cyclin A2 and cyclin E2 decreased with the increase of esomeprazole dose (p<0.05). Compared with the model group, the level of apoptotic protein procaspase-9 in high and low dose groups decreased significantly, while the level of cleaved caspase-9 increased in a dose-dependent manner (p<0.05). The level of protein kinase B in high dose group was lower than that in model group and low dose group, while the level of forkhead box O3 protein increased; the difference was statistically significant (p<0.05). Esomeprazole can affect the biological characteristics of tumor cells such as proliferation and apoptosis by activating protein kinase B/ forkhead box O3 pathway, which provides a new method for the treatment of liver cancer. [ABSTRACT FROM AUTHOR]

Objective To observe the effects of silencing miR-20a-5p on malignant biological behavior and expression of zinc finger protein 3（Zbed3）and Axin in hepatocellular carcinoma cells by regulating Tripartite motif family-like 1 （TRIML1）. Methods Online database TargetScan and double luciferase reporter assay confirmed that TRIML1 was the target gene of miR-20a-5p. Huh-7 cells which had significantly higher expression of miR-20a-5p and TRIML1 than human normal liver cell 7701 were selected for the experiment，and were randomly divided into seven groups. The cells in the model group were cultured normally，and the cells in the miR-20a-5p-NC group were transfected with miR-20a-5p negative control. The cells in the miR-20a-5p siRNA group were transfected with miR-20a-5p siRNA，TRIML1-NC group with TRIML1 negative control，and TRIML1 siRNA group with TRIML1 siRNA，Triml1-NC + miR-20a-5p-NC group with TRIML1 negative control + miR-20a-5p negative control，and TRIML1 siRNA+ miR-20a-5p siRNA group with TRIML1 siRNA+ miR-20a-5p siRNA，and they were all transfected for 48 h. The expression levels of TRIML1 and miR-20a-5p were detected by real-time fluorescence quantitative PCR，the apoptosis rate and the number of migrating and invading cells were detected by flow cytometry and Transwell cell assay，and the expression levels of Zbed3 and Axin proteins were detected by Western blotting. Results No significant differeces were found in the relative expression levels of TRIML1， miR-20a-5p，apoptosis rate，number of migrating cells，number of invading cells or relative expression levels of Zbed3 and Axin proteins between the model group，miR-20a-5p-NC group，TRIML1-NC group and TRIML1-NC+ miR-20a-5p-NC group（all P>0. 05). Compared with the model group，miR-20a-5p-NC group，TRIML1-NC group，and TRIML1-NC+ miR-20a-5p-NC group，the relative expression levels of TRIML1 and miR-20a-5p and the number of migrating cells，invad‐ ing cells and Zbed3 protein decreased，the apoptosis rate and Axin protein relative expression increased，and the changes of TRIML1 siRNA+ miR-20a-5p siRNA group were more obvious in the miR-20a-5p siRNA group，TRIML1 siRNA group， and TRIML1 siRNA+ miR-20a-5p siRNA group（all P<0. 05). Conclusion Silencing the expression of miR-20a-5p can inhibit the invasion and metastasis of Huh-7 cells and the expression of Zbed3，and promote apoptosis and Axin protein expression；the mechanism may be related to the positive regulation of TRIML1 expression. [ABSTRACT FROM AUTHOR]

In order to identify the peptides, selected from the literature, that exhibit the strongest tropism towards human hepatoma cells, cell uptake assays were performed using biotinylated synthetic peptides bound to fluorescent streptavidin or engrafted onto nanoparticles (NPs), prepared from biotin-poly(ethylene glycol)-block-poly(benzyl malate) (Biot-PEG-b-PMLABe) via streptavidin bridging. Two peptides, derived from the circumsporozoite protein of Plasmodium berghei- (CPB) and George Baker (GB) Virus A (GBVA10-9), strongly enhanced the endocytosis of both streptavidin conjugates and NPs in hepatoma cells, compared to primary human hepatocytes and non-hepatic cells. Unexpectedly, the uptake of CPB- and GBVA10-9 functionalized PEG-b-PMLABe-based NPs by hepatoma cells involved, at least in part, the peptide binding to apolipoproteins, which would promote NP's interactions with cell membrane receptors of HDL particles. In addition, CPB and GBVA10-9 peptide–streptavidin conjugates favored the uptake by hepatoma cells over that of the human macrophages, known to strongly internalize nanoparticles by phagocytosis. These two peptides are promising candidate ligands for targeting hepatocellular carcinomas. [ABSTRACT FROM AUTHOR]

A copper-coated magnesium (Cu@Mg) composite has been prepared by electroless plating, with the aim of generating a novel antitumor agent. The cytotoxic effects in vitro of this composite on normal hepatocyte cells (L02) and hepatoma cells (97H) were evaluated by CCK-8 assay. Extract and direct contact tests were conducted with blank groups as the control. Moreover, cell adhesion test was performed with 316L medical stainless steel as the cell carrier. It was found that Cu@Mg composite showed obvious cytotoxic effects on 97H cells but acceptable cytocompatibility whit L02 cells. As illustrated by CCK-8 assay, the cytotoxicity of Cu@Mg on 97H and L02 cells were grade I and III, respectively, and more apoptosis occurred to 97H cells than to L02 cells. During direct contact test, much more pathological reactions such as rounding, shrinking, atrophic edges and clustering were found in 97H cells than those in L02 cells. Similar evidence was shown in the adhesion tests. According to the single-factor cytotoxicity evaluation of pH, Cu ^2+ and Mg ^2+ , the selective cytotoxicity of Cu@Mg on 97H cells is attributed to the fast release of Cu ^2+ and OH ^− , resulting from the degradation of Cu@Mg in the culture medium, but the Mg ^2+ released in the same process shows no toxicity on the both cells. Therefore, it is promising to develop novel antitumor materials on liver cancers with good biocompatibility based on Cu@Mg composite.

This work was designed to compare the sensitizing effects of epigenetic modifiers on cancer cells vs. that of glucocorticoids. Also, to evaluate their effects on genes involved in epigenetic changes and drug metabolism. Hepatoma cells (HepG2) were treated with the anticancer drug (Taxol), with a histone deacetylase inhibitor (Trichostatin A [TSA]), DNA methyltransferase inhibitor (5-Aza-dC) or dexamethasone (DEX). Cytotoxicity was assessed by MTT assay and the apoptosis was determined by Annexin V-FITC. The expression levels of HDAC1, HDAC3, Dnmt1, Dnmt3α, CYP1A2, CYP3A4, CYP2B6, CYP2C19 and CYP2D6 were monitored by qRT-PCR. TSA, synergistically enhanced cells sensitivity with the anticancer effect of Taxol more than 5-Aza-dC and DEX. This was evidenced by the relative decrease in IC50 in cells cotreated with Taxol + TSA, Taxol + 5-Aza-dC or Taxol + DEX. Apoptosis was induced in 51.2, 16.9 and 41.3% of cells, respectively. In presence of Taxol, TSA induced four-fold increase in the expression of HDAC1 and downregulated Dnmt1&3α genes. CYP2D6 demonstrated progressive expression (up to 28-fold) with the increasing number of drugs. Moreover, the isoform overexpressed in cells treated with TSA + Taxol > DEX + Taxol > 5-Aza-dC + Taxol (6.4, 4.6 and 2.99, respectively). The investigated genes were clustered in two distinct subsets, where no coregulation was observed between HDAC1 and HDAC3. However, tight pairwise correlation-based cluster was seen between (CYP3A4/Dnmt3α and CYP2D6/CYP2C19). The data reflects the sensitizing effect of acetylation modification by TSA on the responsiveness of hepatoma cells to anticancer therapy. The effect of histone deacetylase inhibition was more than hypomethylation and glucocorticoid effects. TSA exerts its role through its modulatory role on epigenetics and drugs metabolizing genes. Other modifiers (5-Aza-dC and DEX), however may adopt different mechanisms. [ABSTRACT FROM AUTHOR]

Purpose: Physical activity and professional physical activity such as water polo (WP) sport, has numerous beneficial effects to fight metabolism-related disorders through several mechanisms, including the promotion of liver metabolic adaptations, and the modulation of cytokine production. The aim of this study was to investigate the effects of different types of physical activity on AMPKα and ACC, two proteins involved in liver metabolism; therefore, we treated the hepatoma cell line Hep G2 with sera from elite WP athletes and amateur (basket) players. As control, we used serum from both sedentary and obese subjects. Methods: Help G2 cells were treated with 5% of human sera from the different subjects; after 24 h and 48 h, HepG2 cell viability was verified through MTT assay and activation status of AMPKα and ACC through western blotting. Cytokine's serum levels were measured through ELISA assay. Results: After 72 h, the treatment of HepG2 cells with sera from the different subjects produced no effect on cell viability. Furthermore, after 48 h of treatment, both AMPKα and ACC phosphorylation statistically increases in HepG2 cells treated with sera from WP athletes. Furthermore, IL-4, IL-6 and IL-10 levels resulted statistically increased in WP athlete's sera than in sedentary subjects. Conclusion: The specific activation of AMPKα and ACC by WP sera confirms that professional sport activity carried out by WP athletes can be considered as a physiological activator of these two proteins also in HepG2 liver cells. In addition, the increase of anti-inflammatory cytokines in WP sera confirms the ample evidence for multiple anti-inflammatory activities carried out by WP discipline. [ABSTRACT FROM AUTHOR]

In the current work, we carried out a mechanistic study on the cytotoxicity of two compounds, trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-N-methyl-benzamide (t-AUCMB) and trans-N-methyl-4-{4-[3-(4-trifluoromethoxy-phenyl)-ureido]-cyclohexyloxy}-benzamide (t-MTUCB), that are structurally similar to sorafenib. These compounds show strong cytotoxic responses in various cancer cell lines, despite significant differences in the induction of apoptotic events such as caspase activation and lactate dehydrogenase release in hepatoma cells. Both compounds induce autophagosome formation and LC3I cleavage, but there was little observable effect on mTORC1 or the downstream targets, S6K1 and 4E-binding protein. In addition, there was an increase in the activity of upstream signaling through the IRS1/PI3K/Akt-signaling pathway, suggesting that, unlike sorafenib, both compounds induce mammalian target of rapamycin (mTOR)-independent autophagy. The autophagy observed correlates with mitochondrial membrane depolarization, apoptosis-inducing factor release, and oxidative stress-induced glutathione depletion. However, there were no observable changes in the endoplasmic reticulum-stress markers such as binding immunoglobulin protein, inositol-requiring enzyme-α, phosphorylated eukaryotic initiation factor 2, and the lipid peroxidation marker, 4-hydroxynonenal, suggesting endoplasmic reticulum-independent oxidative stress. Finally, these compounds do not have the multikinase inhibitory activity of sorafenib, which may be reflected in their difference in the ability to halt cell cycle progression compared with sorafenib. Our findings indicate that both compounds have anticancer effects comparable with sorafenib in multiple cell lines, but they induce significant differences in apoptotic responses and appear to induce mTOR-independent autophagy. t-AUCMB and t-MTUCB represent novel chemical probes that are capable of inducing mTOR-independent autophagy and apoptosis to differing degrees, and may thus be potential tools for further understanding the link between these two cellular stress responses.

Objective To investigate the effect of EN2 on the apoptosis and PTEN protein expression in hepatocellular carcinoma cells. Methods Hepatoma cells HuH-7 was infected with EN2 siRNA lentivirus. qRT-PCR and Western blot methods were used to detect the interference effect. The changes of cell vitality was measured by MTT method, PI single staining method was used to determine cell cycle distribution, the apoptosis was measured by Annexin V-FITC/PI double staining, Western blot was used to measure the levels of Cleaved Caspase-3, Cleaved Caspase-9, PTEN and Cyclin B1 protein, the changes of mitochondrial membrane potential was measured by JC-1 method, and Western blot was used to measure the level of Cytochrome C protein in the cytoplasm. Results EN2 siRNA lentivirus infection could significantly reduce the expression of EN2 in hepatocellular carcinoma cells. After EN silence, the activity of hepatoma cells was decreased, the rate of apoptosis was increased, the proportion of G2/M phase in cells was increased, the levels of Cleaved Caspase-3, Cleaved Caspase-9 and PTEN protein were increased significantly, the level of Cyclin B1 protein was decreased significantly, the mitochondrial membrane potential was decreased, and the level of Cytochrome C protein in the cytoplasm was increased. Conclusion Knockdown of EN2 could block the cell cycle of liver cancer and induce the apoptosis of hepatoma cells, and the mechanism may be related to PTEN and mitochondrial apoptotic pathway.

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Hepatoma cells are a promising cell source for the construction of bioartificial liver (BAL) systems owing to their high proliferative capability. However, their low liver function compared with primary hepatocytes is a major problem. In a previous study, we established a genetically modified hepatoma cell line, Hepa/8F5, in which eight liver-enriched transcription factor (LETF) genes were transduced into mouse hepatoma Hepa1-6 cells using a drug-inducible transactivator system. These cells proliferate actively under normal culture conditions, meaning that large quantities can be prepared easily. When the overexpression of the LETFs is induced by the addition of an inducer drug, cell growth stops and cell morphology changes with concomitant high expression of liver functions. However, the liver functions largely depend on the presence of the inducer drug, which must be continuously added to maintain these enhanced functions. In the present study, we attempted to modify the method of induction of LETF overexpression in Hepa/8F5 cells to remove the requirement for continual drug addition. To this end, we constructed a system in which the artificial transactivator was transcribed and amplified under the control of a heat-shock protein promoter, and introduced the system into the genome of Hepa/8F5 cells. In our modified cell line, heat-triggered LETF expression was confirmed to induce high liver function. After drug-screening of transfected cells, we established a hepatoma cell line (Hepa/HS), which exhibited high, heat-inducible liver functions. The Hepa/HS cells may represent a new cell source for hepatic studies such as the construction of BAL systems. [ABSTRACT FROM AUTHOR]

Radiation-induced bystander effects (RIBE) may have potential implications for radiotherapy, yet the radiobiological impact and underlying mechanisms in hypoxic tumor cells remain to be determined. Using two human tumor cell lines, hepatoma HepG2 cells and glioblastoma T98G cells, the present study found that under both normoxic and hypoxic conditions, increased micronucleus formation and decreased cell survival were observed in non-irradiated bystander cells which had been co-cultured with X-irradiated cells or treated with conditioned-medium harvested from X-irradiated cells. Although the radiosensitivity of hypoxic tumor cells was lower than that of aerobic cells, the yield of micronucleus induced in bystander cells under hypoxia was similar to that measured under normoxia indicating that RIBE is a more significant factor in overall radiation damage of hypoxic cells. When hypoxic cells were treated with dimethyl sulfoxide (DMSO), a scavenger of reactive oxygen species (ROS), or aminoguanidine (AG), an inhibitor of nitric oxide synthase (NOS), before and during irradiation, the bystander response was partly diminished. Furthermore, when only hypoxic bystander cells were pretreated with siRNA hypoxia-inducible factor-1α (HIF-1α), RIBE were decreased slightly but if irradiated cells were treated with siRNA HIF-1α, hypoxic RIBE decreased significantly. In addition, the expression of HIF-1α could be increased in association with other downstream effector molecules such as glucose transporter 1 (GLUT-1), vascular endothelial growth factor (VEGF), and carbonic anhydrase (CA9) in irradiated hypoxic cells. However, the expression of HIF-1α expression in bystander cells was decreased by a conditioned medium from isogenic irradiated cells. The current results showed that under hypoxic conditions, irradiated HepG2 and T98G cells showed reduced radiosensitivity by increasing the expression of HIF-1α and induced a syngeneic bystander effect by decreasing the expression of HIF-1α and regulating its downstream target genes in both the irradiated or bystander cells.

Chromenopyrrole derivatives with multiple stereocenters and variable ring fusion pattern are found in many natural products and biologically appealing molecules. By employing a build/couple/pair strategy, we have recently reported on the discovery of a serendipitous cascade to access a diverse collection of chromenopyrroles. This protocol features a one-pot cascade that includes the generation of azomethine ylide and intramolecular [3 + 2]-cycloaddition. Phenotypic screening of the developed pilot library enabled the identification of chemical probes that efficiently suppress mitochondrial membrane potential, elevate reactive oxygen species content, and deplete ATP content in a hepatoma cell line (Hepa1-6), without affecting the proliferation of T- or B-cells. This selective targeting represents a new approach for the treatment of cancer. [ABSTRACT FROM AUTHOR]

Liver cirrhosis and hepatocellular carcinoma are the most common outcomes of chronic hepatitis B. Hepatitis B virus (HBV) induces transformation and cell death in chronic hepatitis B (CHB). DNA double strand breaks (DSBs) represent the most dangerous type of genome damage. It was shown previously that generation of phosphorylated histone H2AX foci is a reliable marker of DSBs. The aim of this study was to analyse generation of yH2AX foci in HBV and hepatitis D virus (HDV) infection in vitro and in liver biopsies of patients with CHB and CHB with delta-agent (CHD). Human hepatoma cell line HepG2-1.1merHBV with activated HBV life cycle was used to perform real-time PCR for analysis of pregenomic RNA, HBV DNA, HBV cccDNA and for immunocytochemical analysis of yH2AX. Liver biopsies from CHB and CHD patients were analyzed to confirm the results. HBV induces multiple discrete yH2AX foci in HepG2-1.1merHBV cells in vitro and in biopsies of CHB and CHB+D patients. The ratio of hepatocytes w/o yH2AX foci is significantly lower (49,9+/-12,3% vs. 85,5+/-0,9%, p

Purpose: To study the impact of matrine on cell cycle and apoptotic changes in hepatoma cells, and the mechanism involved. Methods: Human hepatoma cell line HepG2 was treated with different concentrations of matrine. The blank control cells were maintained in 1640 medium only. The influence of matrine on proliferative ability was determined with 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) method. Flow cytometry was used to determine its effect on cell cycle and apoptosis; RT-PCR (reverse transcription-polymerase chain reaction) was applied to assay the mRNA expressions of miR-122, cyclin G1 (CG1), livin and survivin mRNA, while the protein expressions of CG1, livin and surviving were assayed by Western blotting. Results: Matrine time- and dose-dependently suppressed the proliferative capacity of the cells. At a concentration of 0.5 mg/mL, matrine had no significant effect on the cell cycle. However, 1.0 mg/mL matrine blocked the cell cycle in G1 phase, while 1.5 mg/mL matrine blocked HepG2 cells in G2/M phase (p < 0.05). Moreover, matrine induced apoptosis in HepG2 cells, and markedly downregulated the expressions of miR-122 concentration-time-reliantly (p < 0.05). In addition, matrine markedly and concentration-dependently reduced mRNA and protein expression levels of CG1, livin and survivin, with the strongest inhibitory effect at a level of 1.5 mg/mL. Conclusion: Matrine induces cell cycle block and apoptotic changes in hepatoma cells through a mechanism related to regulation of the CG1/livin/survivin signal axis mediated by miR-122. Matrine may be a potential treatment for liver cancer. However, clinical trials are needed to confirm this potential. [ABSTRACT FROM AUTHOR]

Sorafenib, a multityrosine kinase inhibitor, is a standard treatment for advanced hepatocellular carcinoma (HCC), but the clinical response to sorafenib is seriously limited by drug resistance. Programmed death ligand-1 (PD-L1) is one of the most important inhibitory molecules involved in tumor immune evasion. Recently, it has been reported that PD-L1 could play crucial roles in drug resistance of many kinds of cancers. However, the expression, function, and regulation of PD-L1 in sorafenib-resistant hepatoma cells remain unclear. In this study, we reported that PD-L1 was overexpressed in sorafenib-resistant hepatoma cells, and shRNA-mediated PD-L1 depletion attenuated drug resistance and suppressed the migration, invasion, colony formation, and tumorigenesis in sorafenib-resistant hepatoma cells in vitro and in vivo. Mechanistic investigations indicated that loss of microRNA-1 (miR-1), a tumor-suppressive microRNA, contributed to the PD-L1 upregulation in sorafenib-resistant hepatoma cells, and PD-L1 was a direct regulatory target of miR-1. Further study revealed that an oncogenic transcriptional factor, nuclear factor E2-related factor 2 (NRF-2), was induced in sorafenib-resistant hepatoma cells and inhibited expression of miR-1 in vitro. From molecular mechanism insight back to the functional verification, we eventually demonstrated that miR-1 executed its tumor-suppressive effects on drug resistance and other malignant properties in sorafenib-resistant hepatoma cells partially by PD-L1 inhibition in vitro and in vivo. In conclusion, our data suggested that a NRF-2/miR-1/PD-L1 regulatory axis contributed to the development and maintenance of drug resistance and other tumorigenic properties in sorafenib-resistant hepatoma cells and provided a potential therapeutic target for overcoming sorafenib resistance in HCC. [ABSTRACT FROM AUTHOR]

The liver is targeted by several human pathogenic RNA viruses for viral replication and dissemination; despite this, the extent of innate immune sensing of RNA viruses by human hepatocytes is insufficiently understood to date. In particular, for highly human tropic viruses such as hepatitis C virus, cell culture models are needed to study immune sensing. However, several human hepatoma cell lines have impaired RNA sensing pathways and fail to mimic innate immune responses in the human liver. Here we compare the RNA sensing properties of six human hepatoma cell lines, namely Huh-6, Huh-7, HepG2, HepG2-HFL, Hep3B, and HepaRG, with primary human hepatocytes. We show that primary liver cells sense RNA through retinoic acid-inducible gene I (RIG-I) like receptor (RLR) and Toll-like receptor 3 (TLR3) pathways. Of the tested cell lines, Hep3B cells most closely mimicked the RLR and TLR3 mediated sensing in primary hepatocytes. This was shown by the expression of RLRs and TLR3 as well as the expression and release of bioactive interferon in primary hepatocytes and Hep3B cells. Our work shows that Hep3B cells partially mimic RNA sensing in primary hepatocytes and thus can serve as in vitro model to study innate immunity to RNA viruses in hepatocytes.

Aim: Synthesis of poly-L-lactic acid nanoparticles comprising of microtubule-inhibitor docetaxel and tyrosine kinase inhibitor sorafenib (PLDS NPs) for hepatoma treatment. Materials & methods: PLDS NPs were prepared by the emulsion solvent evaporation method and the anticancer activity was evaluated in Huh7 hepatoma cells. Results: Real-time imaging of quantum dots incorporating poly-L-lactic acid nanoparticles showed a rapid internalization of the nanoparticles in Huh7 cells. PLDS NPs exerted stronger antiproliferative, apoptotic and antiangiogenic effects than free single drug counterparts. They strongly promoted microtubule bundling, multinucleation and increased mitotic index in Huh7 cells. They also inhibited the expression of pERK1/2, pAKT and cyclin D1. Conclusion: We developed a single-nanoscale platform for dual drug delivery and high-sensitivity quantum dots imaging for hepatoma treatment. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between autophagy and radiation damage of human hepatoma cells and to explore the role of reactive oxygen species (ROS). Materials and methods: HepG2 cells were exposed to X-rays, then the protein expressions of microtubule-associated protein 1 light chain 3 (LC3) and poly ADP-ribose polymerase-1 (PARP-1) were measured by Western blot assay, the formation of autophagosomes was detected by an autophagy detection kit, the intracellular ROS level was measured by flow cytometer, and DNA damage was evaluated by the incidence of micronuclei (MN). A CCK-8 kit was used to measure the proliferation ability of irradiated cells with or without N-acetyl-l-cysteine (NAC) treatment. In some experiments, the hepatoma cells were transferred with LC3 siRNA or PARP-1 siRNA before irradiation. Results: The protein expressions of LC3 and PARP-1 and the inductions of autophagosomes and intracellular ROS were increased in the irradiated HepG2 cells. Pretreatment of cells with NAC relieved the irradiation-induced inhibition of cell proliferation. When HepG2 cells were transfected with the LC3 siRNA, the over-expression of PARP-1 was diminished in the irradiated cells. Compared with the control group, the inhibitions of LC3 and PARP-1 increased ROS level in the irradiated HepG2 cells and hence sensitized radiation responses of both proliferation inhibition and MN induction. Conclusion: Autophagy upregulates the expression of PARP-1 and relieves radiation damage by reducing the generation of ROS. [ABSTRACT FROM AUTHOR]

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) progression to fibrosis, cirrhosis and hepatocellular carcinoma, alters the cellular composition of this organ. During late-stage NAFLD, fibrotic and possibly cancerous cells can proliferate and, like normal hepatocytes, are exposed to high concentrations of fatty acids from both surrounding tissue and circulating lipid sources. We hypothesized that primary human activated hepatic stellate cells and epithelial hepatoma (HepG2) cells respond differently to lipotoxic conditions, and investigated the mechanisms involved. Methods: Primary activated hepatic stellate cells and HepG2 cells were exposed to pathophysiological concentrations of fatty acids and comparative studies of lipid metabolic and stress response pathways were performed. Results: Both cell types remained proliferative during exposure to a combination of palmitate plus oleate reflective of the general saturated versus unsaturated fatty acid composition of western diets. However, exposure to either high palmitate or high oleate alone induced cytotoxicity in activated stellate cells, while only palmitate caused cytotoxicity in HepG2 cells. mRNA microarray and biochemical comparisons revealed that stellate cells stored markedly less fatty acids as neutral lipids, and had reduced capacity for beta-oxidation. Similar to previous observations in HepG2 cells, palmitate, but not oleate, induced ER stress and actin stress fiber formation in activated stellate cells. In contrast, oleate, but not palmitate, induced the inflammatory signal TXNIP, decreased cytoskeleton proteins, and decreased cell polarity preceding cell death in activated stellate cells. Conclusions: Palmitate-induced lipotoxicity was associated with ER stress pathways in both primary activated hepatic stellate cells and epithelial hepatoma cells, whereas high oleate caused lipotoxicity only in activated stellate cells, possibly through a distinct mechanism involving disruption of cytoskeleton components. This may have implications for optimal dietary fatty acid compositions during various stages of NAFLD.

Yuexia Xie,1,2,* Dejun Liu,3,* Chenlei Cai,1,* Xiaojing Chen,1 Yan Zhou,1 Liangliang Wu,1 Yongwei Sun,3 Huili Dai,1,2 Xianming Kong,1,2 Peifeng Liu1,2 1Central Laboratory, 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, 3Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mecha­nisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. Keywords: hepatoma cells, nanoparticles, cytotoxicity, mechanism, oxidative stress

While the over-expression of tumor suppressor programmed cell death 4 (PDCD4) induces apoptosis, it was recently shown that PDCD4 knockdown also induced apoptosis. In this study, we examined the cell cycle regulators whose activation is affected by PDCD4 knockdown to investigate the contribution of PDCD4 to cell cycle regulation in three types of hepatoma cells: HepG2, Huh7 (mutant p53 and p16-deficient), and Hep3B (p53- and Rb-deficient). PDCD4 knockdown suppressed cell growth in all three cell lines by inhibiting Rb phosphorylation via down-regulating the expression of Rb itself and CDKs, which phosphorylate Rb, and up-regulating the expression of the CDK inhibitor p21 through a p53-independent pathway. We also found that apoptosis was induced in a p53-dependent manner in PDCD4 knockdown HepG2 cells (p53+), although the mechanism of cell death in PDCD4 knockdown Hep3B cells (p53-) was different. Furthermore, PDCD4 knockdown induced cellular senescence characterized by β-galactosidase staining, and p21 knockdown rescued the senescence and cell death as well as the inhibition of Rb phosphorylation induced by PDCD4 knockdown. Thus, PDCD4 is an important cell cycle regulator of hepatoma cells and may be a promising therapeutic target for the treatment of hepatocellular carcinoma.

The beneficial effects of probiotics in several liver diseases have been investigated in both animal and clinical models; however, the precise mechanisms responsible for their effects have not yet been elucidated. Gut transmitted endotoxins such as LPS have been shown to play critical roles in hepatic inflammation and injury. Therefore, in this study, we investigated the beneficial role of selected lactic acid bacteria (LABs) on reduction of hepatic steatosis (HS) and attenuation of LPS induced inflammatory response in vitro. Total cellular fluid (TCF) of LABs treatment reduced HS by decreasing the amount of lipid accumulation in vitro. Additionally, HepG2 cells exposed to LPS showed increased expression of exacerbated inflammatory cytokines, such as IL-6, CXCL8, CCL2, and TNF-α, but these effects were counteracted when cells were treated with TCF of LABs prior to LPS challenge. Moreover, TCF of LABs was able to modulate mRNA levels of TLR negative regulators and protein levels of p38 MAPK and p65 NF-κB transcription factors. However, these modulations were differed remarkably between both free fatty acid treated and untreated HepG2 cells. Heat-killed LABs were also indirectly suppressed THP-1 cells to produce higher level of IL-10, TLR4, and lower at genes level of TGF-β, IL-1β, and IL-6, and at protein level of TNF-α in response to LPS. Taken together, our findings indicate that selected LABs exhibit profound immunoregulatory effects on liver cells via modulation of TLR negative regulators of the MAPK and NF-κB pathways.

This study describes the comparative expression and purification of hepatitis B surface antigen (HBsAg) particles produced upon infection of human primary hepatocytes and human hepatoma cell lines (HuH-7 and HepG2) with recombinant vaccinia viruses. The highest levels of HBsAg expression were found in HuH-7 hepatoma cells following infection with recombinant vaccinia viruses, which contain the S gene under control of a 7.5 k-promoter. Four different methods for purification of the HBsAg particles were examined: isopycnic ultracentrifugation, sucrose cushion sedimentation, isocratic column gel filtration, and binding to anti-HBs-coated microparticles. The highest degree of purity of HBsAg particles was reached by the method based on anti-HBs-coated microparticles. The resulting product was >98% pure. Biochemical analysis and characterization of purified HBsAg particles were performed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), western blotting, and electron microscopy. The HBsAg, purified from human hepatoma cell lines and from human primary hepatocytes, consisted of both the non-glycosylated (p25) and the glycosylated (gp27) form and assembled into typical 22-nm particles, and thus may be of great interest and importance for research, diagnostics, and medical treatments. [ABSTRACT FROM AUTHOR]

Yellow fever virus (YFV) is a member of the Flaviviridae family. In Brazil, yellow fever (YF) cases have increased dramatically in sylvatic areas neighboring urban zones in the last few years. Because of the high lethality rates associated with infection and absence of any antiviral treatments, it is essential to identify therapeutic options to respond to YFV outbreaks. Repurposing of clinically approved drugs represents the fastest alternative to discover antivirals for public health emergencies. Other Flaviviruses, such as Zika (ZIKV) and dengue (DENV) viruses, are susceptible to sofosbuvir, a clinically approved drug against hepatitis C virus (HCV). Our data showed that sofosbuvir docks onto YFV RNA polymerase using conserved amino acid residues for nucleotide binding. This drug inhibited the replication of both vaccine and wild-type strains of YFV on human hepatoma cells, with EC50 values around 5 μM. Sofosbuvir protected YFV-infected neonatal Swiss mice and adult type I interferon receptor knockout mice (A129-/-) from mortality and weight loss. Because of its safety profile in humans and significant antiviral effects in vitro and in mice, Sofosbuvir may represent a novel therapeutic option for the treatment of YF. Key-words: Yellow fever virus; Yellow fever, antiviral; sofosbuvir [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fabrication of thermosensitive glycopolymers grafted gold nanoparticles (Glyco@GNPs) with multi-functionality. • Glyco@GNPs performed remarkable temperature sensitivity and self-assembled in aqueous solution. • Glyco@GNPs showed stronger affinity to lectin Con A, and Con A can induce aggregation of Glyco@GNPs. • The composites of Glyco@GNPs + Con A can inhibit growth of hepatoma cells SMMC-7721. Abstract Thermosensitive glucose-functionalized glycopolymers grafted gold nanoparticles (Glyco@GNPs) with good colloidal stability and thermosensitive in aqueous solution were fabricated by reversible addition-fragmentation chain transfer (RAFT) mediated one-pot synthesis. The formation of core-shell morphology with about a 60 nm gold core in diameter and a glycopolymer shell of about 80 nm in thickness was indicated by transmission electron microscopy (TEM). The recognition ability of the Glyco@GNPs toward lectin concannavalin A (Con A) was verified by ultraviolet-visible spectroscopy and dynamic light scattering (DLS). The good cytocompatibility of the glycopolymers and Glyco@GNPs was proven by MTT assay on L-929 cells. Glyco@GNPs could effectively inhibit hepatoma cells SMMC-7721 growth after recognizing Con A was also proved by MTT assay and flow cytometry assay. [ABSTRACT FROM AUTHOR]

Ginkgo biloba (EGb761) is a widely used botanical drug. Several reports indicate that EGb761 confers preventive as well as anti-tumorigenic properties in a variety of tumors, including hepatocellular carcinoma (HCC). We here evaluate functional effects and molecular alterations induced by EGb761 in hepatoma cells and non-malignant hepatocytes. Hepatoma cell lines, primary human HCC cells and immortalized human hepatocytes (IH) were exposed to various concentrations (0–1000 μg/ml) of EGb761. Apoptosis and proliferation were evaluated after 72h of EGb761 exposure. Response to oxidative stress, tumorigenic properties and molecular changes were further investigated. While anti-oxidant effects were detected in all cell lines, EGb761 promoted anti-proliferative and pro-apoptotic effects mainly in hepatoma cells. Consistently, EGb761 treatment caused a significant reduction in colony and sphere forming ability in hepatoma cells and no mentionable changes in IH. Transcriptomic changes involved oxidative stress response as well as key oncogenic pathways resembling Nrf2- and mTOR signaling pathway. Taken together, EGb761 induces differential effects in non-transformed and cancer cells. While treatment confers protective effects in non-malignant cells, EGb761 significantly impairs tumorigenic properties in cancer cells by affecting key oncogenic pathways. Results provide the rational for clinical testing of EGb761 in preventive and therapeutic strategies in human liver diseases. [ABSTRACT FROM AUTHOR]

Zika virus (ZIKV) infection during pregnancy has been extensively linked to microcephaly in newborns. High levels of ZIKV RNA were, however, also detected in mice and non-human primates in organs other than the brain, such as the liver. As ZIKV is a flavivirus closely related to the dengue and yellow fever virus, which are known to cause hepatitis, we here examined whether human hepatocytes are susceptible to ZIKV infection. We demonstrated that both human pluripotent stem cell (hPSC)-derived hepatocyte-like cells (HLCs) and the Huh7 hepatoma cell line support the complete ZIKV replication cycle. Of three antiviral molecules that inhibit ZIKV infection in Vero cells, only 7-deaza-2’-C-methyladenosine (7DMA) inhibited ZIKV replication in hPSC-HLCs, while all drugs inhibited ZIKV infection in Huh7 cells. ZIKV-infected hPSC-HLCs but not Huh7 cells mounted an innate immune and NFκβ response, which may explain the more extensive cytopathic effect observed in Huh7 cells. In conclusion, ZIKV productively infects human hepatocytes in vitro. However, significant differences in the innate immune response against ZIKV and antiviral drug sensitivity were observed when comparing hPSC-HLCs and hepatoma cells, highlighting the need to assess ZIKV infection as well as antiviral activity not only in hepatoma cells, but also in more physiologically relevant systems. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) and the malaria parasite Plasmodium use the membrane protein CD81 to invade human liver cells. Here we mapped 33 host protein interactions of CD81 in primary human liver and hepatoma cells using high-resolution quantitative proteomics. In the CD81 protein network, we identified five proteins which are HCV entry factors or facilitators including epidermal growth factor receptor (EGFR). Notably, we discovered calpain-5 (CAPN5) and the ubiquitin ligase Casitas B-lineage lymphoma proto-oncogene B (CBLB) to form a complex with CD81 and support HCV entry. CAPN5 and CBLB were required for a post-binding and pre-replication step in the HCV life cycle. Knockout of CAPN5 and CBLB reduced susceptibility to all tested HCV genotypes, but not to other enveloped viruses such as vesicular stomatitis virus and human coronavirus. Furthermore, Plasmodium sporozoites relied on a distinct set of CD81 interaction partners for liver cell entry. Our findings reveal a comprehensive CD81 network in human liver cells and show that HCV and Plasmodium highjack selective CD81 interactions, including CAPN5 and CBLB for HCV, to invade cells. [ABSTRACT FROM AUTHOR]

The beneficial effects of probiotics in several liver diseases have been investigated in both animal and clinical models; however, the precise mechanisms responsible for their effects have not yet been elucidated. Gut transmitted endotoxins such as LPS have been shown to play critical roles in hepatic inflammation and injury. Therefore, in this study, we investigated the beneficial role of selected lactic acid bacteria (LABs) on reduction of hepatic steatosis (HS) and attenuation of LPS induced inflammatory response in vitro. Total cellular fluid (TCF) of LABs treatment reduced HS by decreasing the amount of lipid accumulation in vitro. Additionally, HepG2 cells exposed to LPS showed increased expression of exacerbated inflammatory cytokines, such as IL-6, CXCL8, CCL2, and TNF-α, but these effects were counteracted when cells were treated with TCF of LABs prior to LPS challenge. Moreover, TCF of LABs was able to modulate mRNA levels of TLR negative regulators and protein levels of p38 MAPK and p65 NF-κB transcription factors. However, these modulations were differed remarkably between both free fatty acid treated and untreated HepG2 cells. Heat-killed LABs were also indirectly suppressed THP-1 cells to produce higher level of IL-10, TLR4, and lower at genes level of TGF-β, IL-1β, and IL-6, and at protein level of TNF-α in response to LPS. Taken together, our findings indicate that selected LABs exhibit profound immunoregulatory effects on liver cells via modulation of TLR negative regulators of the MAPK and NF-κB pathways. [ABSTRACT FROM AUTHOR]

Production of the iron regulatory peptide hepcidin is tightly controlled by a network of proteins in hepatocytes that sense levels of iron in the circulation (as diferric-transferrin) and in tissues (in ferritin). Human studies show high variability in the normal range of serum hepcidin levels. We have postulated that this may, in part, be related to inter-individual variability in the expression of genes in the iron sensing pathway, potentially governed by epigenetic factors. Here, we have investigated whether genes encoding hepatic iron sensing proteins and hepcidin are regulated by DNA methylation. Experiments were performed on two human hepatoma cell lines, HepG2 cells and Huh7 cells. Basal expression of TFR2 and HAMP was significantly lower in Huh7 cells compared with HepG2 cells. Analysis of bisulphite-converted DNA from Huh7 cells revealed partial methylation of TFR2 (alpha transcript), which could result in gene silencing. Demethylation using 5-aza-2’-deoxycitidine (AZA) increased TFR2 mRNA expression in Huh7. PCR analysis of bisulphite-converted HAMP promoter DNA, using methylation-specific primers, revealed no differences between cell lines. However, HAMP mRNA expression in Huh7 was increased by AZA treatment, suggesting that methylation of one or more iron sensing genes may indirectly influence HAMP expression. Our study provides evidence that DNA methylation might control expression of HAMP and other hepatic iron sensing genes, and indicates that epigenetic influences on iron homeostasis warrant further investigation. [ABSTRACT FROM AUTHOR]

Entry of hepatitis C virus (HCV) into hepatocytes is a complex process that involves numerous cellular factors, including the scavenger receptor class B type 1 (SR-B1), the tetraspanin CD81, and the tight junction (TJ) proteins claudin-1 (CLDN1) and occludin (OCLN). Despite expression of all known HCV-entry factors, in vitro models based on hepatoma cell lines do not fully reproduce the in vivo susceptibility of liver cells to primary HCV isolates, implying the existence of additional host factors which are critical for HCV entry and/or replication. Likewise, HCV replication is severely impaired within hepatocellular carcinoma (HCC) tissue in vivo, but the mechanisms responsible for this restriction are presently unknown. Here, we identify tumor-associated calcium signal transducer 2 (TACSTD2), one of the most downregulated genes in primary HCC tissue, as a host factor that interacts with CLDN1 and OCLN and regulates their cellular localization. TACSTD2 gene silencing disrupts the typical linear distribution of CLDN1 and OCLN along the cellular membrane in both hepatoma cells and primary human hepatocytes, recapitulating the pattern observed in vivo in primary HCC tissue. Mechanistic studies suggest that TACSTD2 is involved in the phosphorylation of CLDN1 and OCLN, which is required for their proper cellular localization. Silencing of TACSTD2 dramatically inhibits HCV infection with a pan-genotype effect that occurs at the level of viral entry. Our study identifies TACSTD2 as a novel regulator of two major HCV-entry factors, CLDN1 and OCLN, which is strongly downregulated in malignant hepatocytes. These results provide new insights into the complex process of HCV entry into hepatocytes and may assist in the development of more efficient cellular systems for HCV propagation in vitro. [ABSTRACT FROM AUTHOR]

Oxypeucedanin (OPD), a furocoumarin compound from Angelica dahurica (Umbelliferae), exhibits potential antiproliferative activities in human cancer cells. However, the underlying molecular mechanisms of OPD as an anticancer agent in human hepatocellular cancer cells have not been fully elucidated. Therefore, the present study investigated the antiproliferative effect of OPD in SK-Hep-1 human hepatoma cells. OPD effectively inhibited the growth of SK-Hep-1 cells. Flow cytometric analysis revealed that OPD was able to induce G2/M phase cell cycle arrest in cells. The G2/M phase cell cycle arrest by OPD was associated with the downregulation of the checkpoint proteins cyclin B1, cyclin E, cdc2, and cdc25c, and the up-regulation of p-chk1 (Ser345) expression. The growth-inhibitory activity of OPD against hepatoma cells was found to be p53-dependent. The p53-expressing cells (SK-Hep-1 and HepG2) were sensitive, but p53-null cells (Hep3B) were insensitive to the antiproliferative activity of OPD. OPD also activated the expression of p53, and thus leading to the induction of MDM2 and p21, which indicates that the antiproliferative activity of OPD is in part correlated with the modulation of p53 in cancer cells. In addition, the combination of OPD with gemcitabine showed synergistic growth-inhibitory activity in SK-Hep-1 cells. These findings suggest that the anti-proliferative activity of OPD may be highly associated with the induction of G2/M phase cell cycle arrest and upregulation of the p53/MDM2/p21 axis in SK-HEP-1 hepatoma cells.

In an effort to decrease the toxicity of camptothecin (CPT) and improve selectivity for hepatoma and colon cancer cells, bile acid groups were introduced into the CPT 20 or 10 positions, resulting in the preparation of sixteen novel CPT-bile acid analogues. The compounds in which a bile acid group was introduced at the 20-hydroxyl group of CPT showed better cytotoxic selectivity for human hepatoma and colon cancer cells than for human breast cancer cells. Fluorescence microscopy analysis demonstrated that one compound (E2) entered human hepatoma cells more effectively than it did human breast cancer cells. Compound G4 exhibited the best anti-tumour activity in vivo. These results suggested that introduction of a bile acid group at the 20-position of CPT could decrease toxicity in vivo and improve selectivity for hepatoma cells.

Hepatoma cells are a candidate cell source for bio-artificial livers. However, they exhibit reduced liver functions compared with primary hepatocytes. In our previous study, genetically engineered mouse hepatoma cells were created by transduction with vectors mediating inducible overexpression of eight liver-enriched transcription factors. Upon the induction of the liver-enriched transcription factors transduced, the cells expressed both phenotypic and genotypic liver functions at high levels. In the present study, we performed three-dimensional culture of these cells using macroporous gelatin beads. When immobilized on the macroporous gelatin beads, these cells exhibited further enhancement in liver functionality, including increased albumin secretion, ammonia removal and cytochrome P450 activity. The levels of these functions were significantly enhanced compared to monolayer culture. The method is simple and scalable, and provides highly functional cells that can be used in basic and applied fields of hepatic research. [ABSTRACT FROM AUTHOR]

Thyroid hormones regulate gene expression via both canonical and non-canonical signaling. Hyperthyroidism is associated with elevated plasma levels of fibronectin (FN): in this study we elucidate the molecular mechanism through which triiodothyronine (T3) regulates FN and demonstrate that T3 induces FN expression via a non-canonical pathway by activating hypoxia-inducible factor-1 (HIF-1). We found that T3 treatment increased cellular and secreted FN in human hepatoma cells (HepG2) and human dermal fibroblasts (HF) via the PI3K/Akt/HIF-1 pathway. The inhibition of either Akt phosphorylation with wortmannin or HIF-1 with YC1 in both cell types prevented HIF-1α synthesis and FN positive regulation upon T3 treatment. We showed that HIF-1α overexpression per se was sufficient to up-regulate FN in both cell lines as demonstrated by the transient transfection of both the constitutively active and wild-type forms of HIF-1α. Our data demonstrate the involvement of the PI3K/Akt/HIF-1 pathway in mediating T3 induced FN up-regulation. [ABSTRACT FROM AUTHOR]

T-cell therapy of chronic hepatitis B is a novel approach to restore antiviral T-cell immunity and cure the infection. We aimed at identifying T-cell receptors (TCR) with high functional avidity that have the potential to be used for adoptive T-cell therapy. To this end, we cloned HLA-A*02-restricted, hepatitis B virus (HBV)-specific T cells from patients with acute or resolved HBV infection. We isolated 11 envelope- or core-specific TCRs and evaluated them in comprehensive functional analyses. T cells were genetically modified by retroviral transduction to express HBV-specific TCRs. CD8+ as well as CD4+ T cells became effector T cells recognizing even picomolar concentrations of cognate peptide. TCR-transduced T cells were polyfunctional, secreting the cytokines interferon gamma, tumor necrosis factor alpha and interleukin-2, and effectively killed hepatoma cells replicating HBV. Notably, our collection of HBV-specific TCRs recognized peptides derived from HBV genotypes A, B, C and D presented on different HLA-A*02 subtypes common in areas with high HBV prevalence. When co-cultured with HBV-infected cells, TCR-transduced T cells rapidly reduced viral markers within two days. Our unique set of HBV-specific TCRs with different affinities represents an interesting tool for elucidating mechanisms of TCR-MHC interaction and dissecting specific anti-HBV mechanisms exerted by T cells. TCRs with high functional avidity might be suited to redirect T cells for adoptive T-cell therapy of chronic hepatitis B and HBV-induced hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

MicroRNAs have great therapeutic potential in cancer and other diseases. However, their instability and low in vivo delivery efficiency limits their application. Recombinant PP7 bacteriophage-based virus-like particles (VLPs) could protect microRNAs against rapid degradation by RNase by packaging specific exogenous pre-microRNAs using the pac site. Insertion of a cell-penetrating peptide (CPP) into the AB-loop of VLPs could significantly improve the delivery efficiency of microRNAs into mammalian cells. Unlike other microRNA delivery methods (viral or non-viral vectors), recombinant PP7 VLPs carrying a CPP and microRNA could be efficiently expressed in Escherichia coli using the one-plasmid double expression system. Here we showed that PP7 VLPs carrying a CPP penetrated hepatoma SK-HEP-1 cells and delivered the pre-microRNA-23b, which was processed into a mature product within 24 h; a concentration of 10 nM was sufficient for the inhibition of hepatoma cell migration via the downregulation of liver-intestine cadherin expression. Furthermore, PP7 VLPs carrying a CPP and a pre-microRNA were not infectious, replicative, or cytotoxic. Therefore, recombinant PP7 VLPs can be used for simultaneous and targeted delivery of both microRNAs and peptides because of their ability to package specific exogenous RNA using the pac site and to display peptides. [ABSTRACT FROM AUTHOR]

Background: Despite recent advances in treatment strategies, it is still difficult to cure patients with hepatocellular carcinoma (HCC). Sorafenib is the only approved multiple kinase inhibitor for systemic chemotherapy in patients with advanced HCC. The majority of advanced HCC patients are resistant to sorafenib. The mechanisms of sorafenib resistance are still unknown. Methods: The expression of molecules involved in the mitogen-activated protein kinase (MAPK) signaling pathway in human hepatoma cell lines was examined in the presence or absence of sorafenib. Apoptosis of human hepatoma cells treated with sorafenib was investigated, and the expression of Jun proto-oncogene (c-Jun) was measured. Results: The expression and phosphorylation of c-Jun were enhanced in human hepatoma cell lines after treatment with sorafenib. Inhibiting c-Jun enhanced sorafenib-induced apoptosis. The overexpression of c-Jun impaired sorafenib-induced apoptosis. The expression of osteopontin, one of the established AP-1 target genes, was enhanced after treatment with sorafenib in human hepatoma cell lines. Conclusions: The protein c-Jun plays a role in sorafenib resistance in human hepatoma cell lines. The modulation and phosphorylation of c-Jun could be a new therapeutic option for enhancing responsiveness to sorafenib. Modulating c-Jun may be useful for certain HCC patients with sorafenib resistance. [ABSTRACT FROM AUTHOR]

Alpha-lipoic acid (LA) is a powerful antioxidant. LA has two enantiomers, R(+)-LA (R-LA) and S(−)-LA (S-LA). Of these, R-LA is naturally occurring and an essential cofactor in energy metabolism. R-LA treatment has been reported to affect glucose metabolism in rat hepatoma cells. This study analyzed the time course of metabolite levels in LA-treated cultured H4IIEC3 rat hepatoma cells, including a specific evaluation of the effect of R-LA and the enantioselectivity of LA. Principal component analysis showed that this experiment was well designed to observe enantioselectivity. R-LA treatment was found to inhibit the glycolysis and Thr-Gly-Ser pathways, as well as lactic acid production, leading to the inhibition of gluconeogenesis in starved H4IIEC3 cells. This study may provide mechanistic insight into how R-LA induces apoptosis in hepatoma cells. [ABSTRACT FROM AUTHOR]

ABSTRACT 2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. [ABSTRACT FROM AUTHOR]

Objective: To study the regulatory effect of miR-200a on mesenchymal-epithelial transition factor (MET) and its impact on the biological behavior of hepatoma carcinoma cells. Method: A luciferase reporter assay was used to determine miR-200a's regulatory impact on MET. Human hepatoma HepG2 cells were divided into a control group, a miR-200a group, a MET overexpression group, and a co-transfection group (miR-200a+MET). After culture, cell proliferation ability, cell migration ability, apoptosis, cell invasion ability, and the expression of MET and apoptosis-related (Bcl-2, Caspase-3, Bax) proteins were detected and observed by cell counting kit-8 (CCK-8), scratch assay, Annexin V-FITC staining, transwell chambers, and western blotting. The two groups were compared using the independent sample t-test. The multiple groups were statistically analyzed using one-way ANOVA. Results: The luciferase experiment showed that miR-200a had target MET. The proliferation rate, number of invasions in cells (55.00 ± 7.21, 85.00 ± 7.94, 164.67 ± 19.22, 104.00± 12.29), scratch healing rate (28.33% ± 5.03%, 61.67% ± 4.04%, 74.67% ± 7.02%, 49.33% ± 9.02%), and expression levels of MET, Bcl-2, and Caspase-3 proteins were lower in the miR-200a group than those in the control group, MET overexpression group, and co-transfection group, while the MET overexpression group had higher indexes than the other three groups, with statistically significant differences between the groups ( P <0.05). The apoptosis rate of HepG2 cells and the expression level of Bax protein were higher in the miR-200a group than those in the control group, MET overexpression group, and co-transfection group (19.25% ± 2.98%, 6.80% ± 1.15%, 3.42% ±0.76%, 9.90% ± 2.72%), while the levels of various indexes in the MIF overexpression group were lower than those in the other three groups. The control group and co-transfection group were between the two groups, and the difference between the groups was statistically significant ( P <0.05). Conclusion: HepG2 cell proliferation, migration, invasion, and cell apoptosis induction can be inhibited by miR-200a, and the functional mechanism for this may be associated with the miR-200a target's ability to down-regulate MET expression in HepG2 cells.