SK-Hep1 Cells Research Articles

Upregulation of hypoxia-inducible factor 1α mRNA expression was associated with poor prognosis in patients with hepatocellular carcinoma.

BackgroundHIF1α mRNA expression in hepatocellular carcinoma (HCC) tissues and its relationship with the prognosis in HCC patients is still unclear. We performed this study to investigate the expression of HIF1α mRNA and its correlation with the prognosis in HCC patients.Materials and methodsGSE14520 and Oncomine database were used to analyse the differential expression of HIF1α mRNA among HCC tissues and corresponding peritumour tissues or normal liver tissues. The relationship between HIF1α mRNA expression and the clinicopathological features and survival in HCC patients was analysed using the GSE14520 dataset. CCK-8 assay, wound-healing assay, transwell invasion assay, tube formation assay, and subcutaneous xenograft tumour assays using nude mice were used to confirm the function of HIF1α.ResultsExpression of HIF1α mRNA was significantly upregulated in HCC tissues (P<0.05 in all cases); this was supported by the results of the Western blotting (P=0.031) and IHC analyses. Our analysis of the clinicopathological features of HCC patients indicated that high HIF1α mRNA expression was strongly related with TNM stage III (P=0.002) and BCLC stage C (P=0.038). Survival analysis demonstrated that HCC patients with high HIF1α mRNA expression had a short overall survival (OS) (P=0.048), but showed no significant difference in recurrence-free survival (RFS) (P=0.066) compared to patients with low HIF1α mRNA expression. We further demonstrated that HIF1α promoted the proliferation, migration, invasion, and angiogenic ability of HCC cells, by using the stably transformed SK-Hep1 and Hep-3B cell lines showing HIF1α overexpression. Finally, xenograft tumour models of nude mice showed that RNA interference-mediated HIF1α silencing suppressed tumour growth and angiogenesis in HCC.ConclusionOur study suggests that the upregulation of HIF1α mRNA, which is found in HCC tissues and associated with poor prognosis in HCC patients, contributed to the proliferation, migration, invasion, and angiogenic ability of HCC cells.

The Effects of Metformin on Age-Related Changes in the Liver Sinusoidal Endothelial Cell.

Age-related changes in the liver sinusoidal endothelium, particularly the reduction in fenestrations, contribute to insulin resistance in old age. Metformin impacts on the aging process and improves insulin resistance. Therefore, the effects of metformin on the liver sinusoidal endothelium were studied. Metformin increased fenestrations in liver sinusoidal endothelial cells isolated from both young and old mice. Mice administered metformin in the diet for 12 months had increased fenestrations and this was associated with lower insulin levels. The effect of metformin on fenestrations was blocked by inhibitors of AMP-activated protein kinase (AMPK), endothelial nitric oxide synthase, and myosin light chain kinase phosphorylation. Metformin led to increased transgelin expression and structural changes in the actin cytoskeleton but had no effect on lactate production. Metformin also generated fenestration-like structures in SK-Hep1 cells, a liver endothelial cell line, and this was associated with increased ATP, cGMP, and mitochondrial activity. In conclusion, metformin ameliorates age-related changes in the liver sinusoidal endothelial cell via AMPK and endothelial nitric oxide pathways, which might promote insulin sensitivity in the liver, particularly in old age.

Asparagus Polysaccharide Suppresses the Migration, Invasion, and Angiogenesis of Hepatocellular Carcinoma Cells Partly by Targeting the HIF-1α/VEGF Signalling Pathway In Vitro.

Hypoxia-inducible factor-1α (HIF-1α) plays a key role by triggering the transcriptional activation of a number of genes involved in migration, invasion, and angiogenesis in hepatocellular carcinoma (HCC). Thus, suppressing tumour growth by targeting the HIF-1α/VEGF signalling pathway represents a promising strategy for the treatment of HCC. In our previous studies, we found that asparagus polysaccharide (ASP) suppressed the proliferation and promoted the apoptosis of HCC cells both in vivo and in vitro. To further explore the potential mechanisms of the antitumor effects of ASP in HCC, we investigated effects of ASP on the migration, invasion, and angiogenesis of HCC cells (SK-Hep1 and Hep-3B) using an in vitro experimental model. First, we found that ASP effectively suppressed the proliferation of the SK-Hep1 and Hep-3B cells but did not cause significant cytotoxicity in normal liver cells (L-O2). Then, we found that ASP inhibited the migration and invasion of the SK-Hep1 and Hep-3B cells and HCC cells-induced angiogenesis of human umbilical vein endothelial cells in a concentration-dependent manner. Mechanistic studies revealed that the inhibition of migration, invasion, and angiogenesis by ASP in the SK-Hep1 and Hep-3B cells might occur via the downregulation of HIF-1α/VEGF signalling pathway. Finally, our results also showed that the inhibition of HIF-1α by ASP may be mediated through the downregulation of the phosphorylation levels of AKT, mTOR, and ERK. In conclusion, our results suggest that ASP suppresses the migration, invasion, and angiogenesis of HCC cells partly via inhibiting the HIF-1α/VEGF signalling pathway.

Histone deacetylase 6-EGFR axis in recurrent hepatocellular carcinoma.

e15638 Background: Alterations of histone deacetylases (HDACs) and related signaling have been increasingly associated with cancer development and treatment. Among those HDACs, HDAC6 uniquely functions in maintaining mRNA stability of certain genes. The aim of this study was to determine the clinical impacts and associated mechanisms of HDAC6 in hepatocellular carcinoma (HCC). Methods: Immunohistochemistry is firstly applied to analyze the distribution patterns of HDAC6 in 122 patients and the obtained results are statistically analyzed with clinicopathological characteristics and patient survival. XTT, flowcytometery, transwell assay, real-time PCR, IF, IB, immunoprecipitation (IP), and RNA-IP are used to determine the bio-impacts and underlying mechanisms of HDAC6 in liver cancer cells. Results: Both cytoplasmic and nuclear staining of HDAC6 proteins were mainly decreased in cancerous lesions. Nevertheless, increased cytoplasmic HDAC6 staining was positively correlated with disease recurrence (p = 0.002). Increased nuclear frequency, but not cytoplasmic intensity, of HDAC6 was associated with a poor survival rate in HCC patients (p = 0.041). Restoration of HDAC6 expression increased the proliferation, S phase, migration and invasion of the HepJ5, Huh7 and Mahlavu cells, lacking detectable HDAC6 expression. More interestingly, ectopic HDAC6 overexpression increased a ligand-independent expression of p-AKT, beta-catenin and cyclin D, and subsequently promoted the entry of beta-catenin into the nucleus. Both transcripts and proteins of the EGFR, a dominant trigger of AKT signaling, were unexpectedly increased upon HDAC6 restoration in HepJ5, Huh7 and Mahlavu cells. The expression of EGFR was not restored by treatment with MG132 (proteasome inhibitor) in HepJ5, Huh7 and Mahlavu cells, and HDAC6-specific siRNA decreased both HDAC6 and EGFR expression in Hep3B and SK-Hep1 cells, having detectable HDAC6 and EGFR expression. IP and RNA-IP analysis revealed that HDAC6 interacted with HuR and increased EGFR mRNA stability. Accordingly, the expression of HDAC6 and EGFR were positively correlated in cancerous lesions. Conclusions: Our results suggest that the contribution of HDAC6 to recurrent HCC may act through its maintenance of EGFR mRNA stability. HDAC6 may serve as a rational treatment target in recurrent HCC.

Advanced liquid chromatography-mass spectrometry enables merging widely targeted metabolomics and proteomics

Either widely targeted metabolomics or quantitative proteomics usually requires unique analytical platform. However, cross-platform omics studies entail higher levels of complexity and uncertainty, and result in a significant obstacle for high throughput assay as well. It is thereby urgent to pursue an integrative approach being capable of merging these two omics terms, namely widely targeted bi-omics. As an eligible analytical tool for large-scale targeted metabolomics, reversed phase liquid chromatography-hydrophilic interaction liquid chromatography–tailored selected reaction monitoring (RPLC-HILIC–tailored SRM) was deployed here to further receive the tryptic peptides as the analytes. Comparative evaluation of metabolites and tryptic peptides, 101 ones in total, between HepG2 and SK-Hep1 cells was conducted as a proof-of-concept. All analytes, regardless of metabolites or peptides, exhibited satisfactory chromatographic behaviors on RPLC-HILIC. Quantitative MS parameters, such as SRM transitions and collision energies (CEs), of either tryptic peptides or metabolites were online optimized in a standard compound-independent manner. It was worthwhile to mention that the signal responses of the peptides-of-choice generated by the optimized CEs were significantly superior to those values suggested by Skyline software. Calibration curves of both metabolites and peptides were constructed by serially diluting a so-called universal metabolome standard (UMS) sample. The quasi-content of each peptide or metabolite was gained according to applying those regressive calibration curves. After subjecting the quasi-content dataset into SIMCA-P software, significant differences took place between the two hepatic cell lines, and not only metabolites but tryptic peptides contributed to the discrimination. Above all, RPLC-HILIC–tailored SRM offered a promising choice towards widely targeted bi-omics attributing to the advantage of simultaneous monitoring metabolites and tryptic peptides.

Fluoxetine Induces Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits ERK/NF-κB-Modulated Anti-Apoptotic and Invasive Potential in Hepatocellular Carcinoma Cells In Vitro.

The aim of the present study was to verify the effects of fluoxetine on dysregulation of apoptosis and invasive potential in human hepatocellular carcinoma (HCC) SK-Hep1 and Hep3B cells. Cells were treated with different concentrations of fluoxetine for different times. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assays were used for testing the effects of fluoxetine on cell viability. The regulation of apoptosis signaling, and anti-apoptotic, proliferation, and metastasis-associated proteins after fluoxetine treatment were assayed by flow cytometry and Western blotting assay. The detection of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation after fluoxetine treatment was performed by NF-κB reporter gene assay. The results demonstrated that fluoxetine significantly reduced cell viability, cell migration/invasion, NF-κB, extracellular signal-regulated kinases (ERK) activation, and expression of anti-apoptotic (Cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (C-FLIP), Myeloid cell leukemia-1 (MCL-1), X-Linked inhibitor of apoptosis protein (XAIP), and Survivin), proliferation (Cyclin-D1), angiogenesis (vascular endothelial growth factor (VEGF)), and metastasis-associated proteins (matrix metalloproteinase-9 (MMP-9)). Fluoxetine also significantly induced apoptosis, unregulated extrinsic (activation of first apoptosis signal protein and ligand (Fas/FasL), and caspase-8) and intrinsic (loss of mitochondrial membrane potential (ΔΨm) pathways and increased Bcl-2 homologous antagonist killer (BAK) apoptosis signaling. Taken together, these results demonstrated that fluoxetine induced apoptosis through extrinsic/intrinsic pathways and diminished ERK/NF-κB-modulated anti-apoptotic and invasive potential in HCC cells in vitro.

PCK1 negatively regulates cell cycle progression and hepatoma cell proliferation via the AMPK/p27Kip1 axis

BackgroundAltered glucose metabolism endows tumor cells with metabolic flexibility for biosynthesis requirements. Phosphoenolpyruvate carboxykinase 1 (PCK1), a key enzyme in the gluconeogenesis pathway, is downregulated in hepatocellular carcinoma (HCC) and predicts poor prognosis. Overexpression of PCK1 has been shown to suppress liver tumor growth, but the underlying mechanism remains unclear.MethodsmRNA and protein expression patterns of PCK1, AMPK, pAMPK, and the CDK/Rb/E2F pathway were determined using qRT-PCR and western blotting. Cell proliferation ability and cell cycle were assessed by MTS assay and flow cytometric analysis. The effect of PCK1 on tumor growth was examined in xenograft implantation models.ResultsBoth gain and loss-of-function experiments demonstrated that PCK1 deficiency promotes hepatoma cell proliferation through inactivation of AMPK, suppression of p27Kip1 expression, and stimulation of the CDK/Rb/E2F pathway, thereby accelerating cell cycle transition from the G1 to S phase under glucose-starved conditions. Overexpression of PCK1 reduced cellular ATP levels and enhanced AMPK phosphorylation and p27Kip1 expression but decreased Rb phosphorylation, leading to cell cycle arrest at G1. AMPK knockdown significantly reversed G1-phase arrest and growth inhibition of PCK1-expressing SK-Hep1 cells. In addition, the AMPK activator metformin remarkably suppressed the growth of PCK1-knockout PLC/PRF/5 cells and inhibited tumor growth in an orthotropic HCC mouse model.ConclusionThis study revealed that PCK1 negatively regulates cell cycle progression and hepatoma cell proliferation via the AMPK/p27Kip1 axis and supports a potential therapeutic and protective effect of metformin on HCC.

Cholesterol attenuated the progression of DEN-induced hepatocellular carcinoma via inhibiting SCAP mediated fatty acid de novo synthesis

Worldwide, hepatocellular carcinoma (HCC) remains a top instigator of cancer mortality. Previous clinical studies have revealed that low serum cholesterol predicts a poor outcome in HCC patients, but the potential role of cholesterol in the progression of HCC remains controversial. In the present study,we tested the influence of cholesterol on the progression of DEN-induced HCC by feeding mice with a high cholesterol diet (HCD) and by depriving cholesterol with atorvastatin, a widely used inhibitor of the mevalonate pathway. We found that HCD induced more and larger liver tumors and an increased occurrence of lung metastasis in DEN-injected mice. These effects could be prevented by cholesterol deprivation with atorvastatin. In vitro, cholesterol loading repressed the proliferation, migration, and the invasion of SK hep1 cells, which was additionally prevented by cholesterol deprivation. Both in vivo and in vitro, cholesterol loading decreased the expression of Sterol regulatory element-binding protein cleavage-activating protein (SCAP), the translocation of sterol regulatory element-binding protein1 (SREBP1) to the nucleolus, and the genetic expression of FAS and ACC-1. Over-expression of SCAP in cholesterol-loaded SK hep1 cells promoted the nuclear translocation of SREBP1 and the expression of FAS and ACC-1, which promoted the proliferation, migration, and the invasion of SK hep1 cells. Knockdown of SCAP also restrained the cholesterol deletion-mediated up-regulation of fatty acid de novo synthesis in SK hep1 cells, inhibiting the atorvastatin-mediated proliferation, migration, and invasion of SK hep1 cells. In conclusion, cholesterol inhibited the progression of HCC through restraining SCAP-mediated fatty acid de novo synthesis.

Prx2 links ROS homeostasis to stemness of cancer stem cells

Cancer stem cells (CSC) with low levels of reactive oxygen species (ROS) are resistant to conventional chemotherapy or radiation therapy. Peroxiredoxin 2 (Prx2) is a redox regulatory protein that plays a key role in maintaining ROS homeostasis in the tumor microenvironment. However, despite the role of Prx2 in ROS-mediated signal transduction, the association of Prx2 with stemness via ROS in CSC has not been thoroughly investigated. In this study, we investigated the link between Prx2 and CSC stemness through regulation of ROS levels in hepatocellular carcinoma (HCC) cells. ROS induced CSC stemness reduction and downregulated stem cell markers in Huh7 and SK-HEP1 cells. Prx2 knockdown decreased CSC sphere formation and expression of stem cell makers with increasing intracellular ROS levels. This effect was reversed by the ROS scavengers NAC and GSH in Prx2 knockdown cells. Conversely, we found that Prx2 overexpression promotes CSC stemness and the peroxidase activity of Prx2 is essential for CSC stemness using peroxidase inactive mutant, Prx2C51/172S. More importantly, the hyperoxidation-resistant mutant (Prx2ΔYF), which has a constant ROS scavenging activity even at high concentrations of ROS, increased the CSC stemness and expression of stem cell markers more than Prx2WT under oxidative stress. Taken together, our findings demonstrate that Prx2 links ROS homeostasis to CSC stemness; Prx2 is a mediator between ROS homeostasis and CSC stemness.

Effect of IRAK1 on Apoptosis and Necroptosis of Hepatoma Cell Line SK-Hep1

Interleukin I receptor associated kinase 1 (IRAK1) is a downstream signal molecule of activated MyD88 recruitment, which can activate Fas associated death domain protein (FADD) to induce apoptosis. IRAK1 can also activate tumor necrosis factor-related factor 6 (TRAF6) and induce the expression of a series of downstream specific genes. IRAK1 is an essential factor in the induction of mitochondrial division and necroptosis. In the current study, RNAi technique was used to silence IRAK1, and the apoptosis and necroptosis rate of SK-Hep1 cells were detected by flow cytometry. The apoptosis and the necroptosis pathway of hepatoma SK-Hep1 cells were blocked separately, and the expressions of FADD, RIP1 and TRAF6 genes were silenced separately. The results showed when the expression of IRAK1 was down-regulated, the apoptosis and necroptosis rate of SK-Hep1 cells were significantly increased. With silenced FADD, RIP1 and TRAF6, respectively, the expression of IRAK1 protein had no significant change. However, the expression of IRAK1 mRNA decreased significantly (p < 0.01) after the silencing of RIP1 and TRAF6 genes, while the IRAK1 mRNA did not change significantly after the silencing of FADD genes; when z-VAD-FMK was interfered, the expression of IRAK1 mRNA decreased significantly after the silencing of TRAF6 genes, while the IRAK1 mRNA did not change significantly after the silencing of FADD and RIP1genes. The study shows that RAK1 gene inhibits apoptosis and necroptosis in SK-Hep1 cells. TRAF6 gene affected the role of IRAK1 in apoptosis and necroptosis, RIP1 gene affected the role of IRAK1 in apoptosis, while FADD gene did not affect the role of IRAK1 in apoptosis and necroptosis.

Effects of Mitochondrial DNA Deletion and OSW-1 on PI3K-AKT Signaling Pathway PCR Array in SK-Hep1 Cells

To investigate the effect of mitochondrial DNA deletion and OSW-1 on PI3K-AKT signaling pathway PCR Array in SK-Hep1 hepatocellular carcinoma cells, we prepared SK-Hep1 cells with mtDNA deletion, that is, p0SK Hep. Then the OSW-1 of 100 ng/L was used to intervene SK-Hep1 and p0SK-Hep1. RT-qPCR was used to detect the difference of gene expression on PI3K-AKT signaling pathway PCR Array in four groups of cells. The gene expression of TLR4, FOS and TSC2 markers in SK-Hep1 cells treated with OSW-1 were significantly increased. The gene expressions of PDPK1, GJA1, TLR4 and TSC2 markers were significantly increased in p0SK-Hep1 cells, and the gene expressions of IRAK1 and GJA1 markers were significantly increased in p0SK-Hep1 cells treated with OSW-1. OSW-1 mainly affects the genes related to TLR4 pathway on PI3K-AKT signaling pathway PCR Array in SK-Hep1 HCC cells. P0SK-Hep1 mainly affects the upstream PDK1 gene and downstream TSC2 gene of Akt on PI3K-AKT signaling pathway PCR Array, and also affects the gene expression of gap junction at the same time.

Effects of high fat medium conditions on cellular gene expression profile: a network analysis approach.

This study aimed to evaluate high fat medium (HFM) effect on the gene expression profile of human Sk-hep1 cells and to determine critical differential proteins. There is a correlation between high fat diet (HFD), obesity, and non-alcoholic fatty liver disease. Despite wide range of investigations, understanding molecular mechanism of HFD effect on onset and progression of NAFLD warrants further examination. In this study, network analysis is applied to obtain a clear perspective about HFD effects and NAFLD. Gene expression profiles of human Sk-hep1 cells treated with HFM versus controls were extracted from GEO. Data were analyzed by GEO2R where the significant and characterized DEGs were included in the PPI network. The top 10 nodes of query DEGs based on four centrality parameters were selected to determine central nodes. The common hub nodes with at least other one central group were identified as central nodes. Action map was provided for the introduced central nodes. Heterogeneous nuclear ribonucleoprotein family including A1, A2/B1, D, R, and D-like, and five proteins (PRPF40A, SRSF1, PCF11, LSM8, and HSP90AA1) were introduced as differential proteins. mRNA processing and several biological terms including hypoxia and oxidative stress, apoptosis, regulation of cell morphology and cytoskeletal organization, and differentiation of micro tubes were introduced as dysregulated terms under HFM condition.

Anti-growth Effects of Imatinib and GNF5 via Regulation of Skp2 in Human Hepatocellular Carcinoma Cells.

BackgroundHuman hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells.MethodsCell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated.ResultsImatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5.ConclusionsThese results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

Dependence of artesunate on long noncoding RNA-RP11 to inhibit epithelial-mesenchymal transition of hepatocellular carcinoma.

As a first line medicine for malaria treatment, artesunate (ART) also shows antitumor potential. However, little is known about the effect of ART on the cancer cell epithelial-mesenchymal transition (EMT). In this study, we found that ART inhibited cell growth in SK-HEP1 and SM7721 hepatocellular carcinoma cell lines. A microarray was used to identify differentially expressed protein-coding RNAs (pcRNA) and long noncoding RNAs (lncRNA) between SK-HEP1 cells with and without ART treatment. A differentially expressed lncRNA-RP11, the most related to the EMT of liver cancer cells-RP11 was identified by abioinformatics method Overexpressing and silencing assays were used to verify the role of RP11 in cancer cell EMT. The levels of RP11- and EMT-related genes in liver cancer samples from 75patients were detected by using qualitative polymerase chain reaction or immunohistochemistry. We identified 1334 pcRNAs and 1670 lncRNA with differential expression induced by ART. ART inhibits EMT, proliferation, migration, invasion, and adhesion of liver cancer cells. RP11 depresses the inhibitory effect of ART on cancer cell EMT. The level of RP11 is associated with cancer cell EMT and metastasis and survival rate of the patient. These data suggest that RP11-linking ART and cancer cell EMT are important for ART-inhibited metastasis of liver cancer.

NEK2 Promotes Hepatoma Metastasis and Serves as Biomarker for High Recurrence Risk after Hepatic Resection

Introduction and aim. Developing reliable biomarkers for hepatocellular carcinoma (HCC) patients who are at a high risk of recurrence after curative hepatic resection is very important for determining subsequent therapeutic strategies. We investigated the role of the cell cycle factor NIMA-related kinase 2 (NEK2) in HCC progression in hepatoma cells and post-surgery patients.Material and methods. The effects of NEK2 on proliferation, invasion and migration of hepatoma HuH7 and SK-Hep1 cells were evaluated. In a post-surgery HCC cohort (N = 97), the Nek2 induction levels in the tumors were examined with real-time RT-PCR analysis, and the results were analyzed for their correlations with recurrence.Results. NEK2 promoted G1 to S phase cell cycle progression by causing increases in cyclin D1 and AKT phosphorylation and decreases in the cyclin-dependent kinase inhibitor p27, indicating that NEK2 plays an important role during interphase in addition to its previously identified role in M phase. NEK2 also enhanced the proliferation, migration and invasion of hepatoma cells and regulated the expression of E-cadherin and MMP9. The Nek2 mRNA levels in the tumors were highly correlated with recurrence rates in the post-surgery HCC patients. Combined evaluation of the tumor AJCC stage and the Nek2level can serve as a reliable method for predicting the relative risk of HCC recurrence in these patients. Conclusions. NEK2 plays a significant role in cell cycle progression in the inter- and M-phases. NEK2 enhances HCC metastasis and is correlated with recurrence and thus can potentially serve a promising high-risk biomarker for HCC.

P21-activated kinase 4 as a switch between caspase-8 apoptosis and NF-κB survival signals in response to TNF-α in hepatocarcinoma cells

PAK4 is overexpressed in a variety of human cancers and considered a promising candidate for therapeutic target. However, its functions remain poorly understood, especially in liver carcinogenesis which could be triggered by inflammation. In the present study, endogenous PAK4 was knockdown using siRNA in HepG2 and SK-Hep1 cells. The two cell lines performed reduced cell viability, altered cell cycle composed of decreased S and arrest in G2, and apoptosis. Meanwhile, expression of NF-κB p65 in the nuclei and caspase-8 activity did not show significant differences from control. However, after treating cells with TNF-α, an inflammatory cytokine, we investigated repressed nuclear expression and localization of NF-κB p65, and induced apoptosis with increased caspase-8 activity in PAK4-knockdown cells. The findings revealed that ablation of PAK4 inhibited cell viability via blocking cell cycle and progressing apoptosis. The apoptosis was partially dependent upon caspase-8 concomitant with attenuated NF-κB survival signal due to stimulus of TNF-α. It suggests that PAK4 as target is a switch between caspase-8 apoptosis and NF-κB survival signals induced by TNF-α in hepatocarcinoma cells.

Bufalin inhibits cell proliferation and migration of hepatocellular carcinoma cells via APOBEC3F induced intestinal immune network for IgA production signaling pathway

ObjectiveThis study aimed to evaluate functions of APOBEC3F gene in biological process of hepatocellular carcinoma (HCC) and anti-tumor mechanisms of bufalin. MethodsEffect of APOBEC3F and bufalin on cell proliferation and migration abilities were evaluated by CCK-8, wounding healing tests and transwell assays in SK-Hep1 and Bel-7404 cells. Bioinformatic analysis were also used to compare APOBEC3F expression levels, detect coexpressed genes and enrichment of pathways. ResultsAPOBEC3F was overexpressed in tumor tissues compared to adjacent tissues in HCC patients. And, APOBEC3F promotes cell proliferation and migration in SK-Hep1 and Bel-7404 cells. Bufalin inhibits cell proliferation and migration and reduces APOBEC3F expression. GO and KEGG enrichment of APOBEC3F-coexpressed genes revealed that APOBEC3F might active intestinal immune network for IgA production signaling pathway, leading to malignant biological behaviors of HCC cells. Additionally, siAPOBEC3F could decrease pIgR, CCR9, CCR10 and CXCR4 protein levels. And, bufalin inhibits the pIgR, CCR9, CCR10 and CXCR4 protein expressions. ConclusionsBufalin inhibits cell proliferation and migration of HCC cells via APOBEC3F induced intestinal immune network for IgA production signaling pathway.

Abstract 341: The role of telomere protective protein TPP1 in hepatocellular carcinoma

Abstract Hepatocellular carcinoma (HCC) is a worldwide malignancy. To date, surgery is still the most effective treatment with curative potential, but only about 20% of patients with HCC are eligible for surgical intervention. Therefore exploring the pathogenesis of liver cancer, looking for molecules targeting therapy, is very important. Telomeres, the chromosome extremities, are protected by specific proteins, such as POT1, RAP1, TIN2, TRF1, TRF2,and TPP1. More and more findings have discovered that TPP1 plays an important role in the tumorigenesis. However, the mechanism of TPP1 in HCC remains unknown. The purpose of this study is to explore the role of TPP1 in HCC. Currently 42 cases of HCC patients were recruited in this study. First, the patients' tumor tissue, adjacent tissue and normal tissue were analyzed by Western blot. The results showed that TPP1 expression in patients' adjacent tissue and normal tissue was lower than that in tumor tissue, respectively (P&amp;lt;0.05; P&amp;lt;0.05). Furthermore, investigation on the protein expression levels of TPP1 with clinicopathologic characteristics discovered that the higher TPP1 in patients' tumor tissue was correlated with the tumor clinical stages, demonstrating that those patients who were in earlier stages (I + II) showed lower TPP1 protein levels than those in later or advanced stages (III + IV) (P&amp;lt;0.05). More importantly, the survival analysis showed that the overall survival was significantly shorter in patients with high TPP1 expression than in others (P&amp;lt;0.05). To further study the role of telomere protective protein TPP1 in HCC, we used lentiviral shRNA embedding TPP1 to knock down the expression of TPP1 in HepG2 and SK-Hep1 cells. The cell growth curve results showed that knockdown of TPP1 could inhibit the growth and proliferation of the above cells. Meanwhile we found that the migration and invasion abilities of the cells were significantly reduced by knocking down the expression of TPP1 compared with the cells transfected with the control lentiviral shRNA. Through scratch test and cell invasion transwell chamber test, TPP1 depletion dramatically suppressed the colony formation on soft agar, which indicated that TPP1 loss could reduce the transformation ability of HCC. More interestingly, we found that ATM pathway was activated after knockdown of TPP1, resulting in γ-H2AX and phosphorylated ATM(p-ATM) upregulation. On the other hand, removal of TPP1 initiated mTOR pathway activation, which resulted in phosphorylated mTOR (p-mTOR) augmentation, followed by the increase of p70S6K and 4EBP1 phosphorylation. Eventually the autophagy marker LC3 I/II conversion and p62 declined obviously by depletion of TPP1 in HepG2 and SK-Hep1 cells. Taken together, TPP1 could be a potential predictor of hepatocellular carcinoma staging and overall survival, and targeting TPP1 might be a therapeutic approach for HCC. Citation Format: Jiang Zou, Ru Sun, Jingruo Xia, Dan Xiao, Chang Liu, Hebin Liao, Lei Xu, Qiang Ma, Yan Cai, Jingdong Li, Xiaolan Guo. The role of telomere protective protein TPP1 in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 341.

Dual Acting Polymeric Nano-Aggregates for Liver Cancer Therapy.

Liver cancer treatments are often hindered by poor drug physicochemical properties, hence there is a need for improvement in order to increase patient survival and outlook. Combination therapies have been studied in order to evaluate whether increased overall efficacy can be achieved. This study reports the combined treatment of liver cancer cells with a combination treatment of chemotherapeutic agent paclitaxel and pro-apoptotic protein cytochrome C. In order to administer both agents in a single formulation, a poly(allylamine)-based amphiphile has been fabricated with the incorporation of a hybrid iron oxide-gold nanoparticle into its structure. Here, the insoluble paclitaxel becomes incorporated into the hydrophobic core of the self-assemblies formed in an aqueous environment (256 nm), while the cytochrome C attaches irreversibly onto the hybrid nanoparticle surface via gold-thiol dative covalent binding. The self-assemblies were capable of solubilising up to 0.698 mg/mL of paclitaxel (700-fold improvement) with 0.012 mg/mL of cytochrome C also attached onto the hybrid iron oxide-gold nanoparticles (HNPs) within the hydrophobic core. The formulation was tested on a panel of liver cancer cells and cytotoxicity was measured. The findings suggested that indeed a significant improvement in combined therapy (33-fold) was observed when compared with free drug, which was double the enhancement observed after polymer encapsulation without the cytochrome C in hepatocellular carcinoma (Huh-7D12) cells. Most excitingly, the polymeric nanoparticles did result in improved cellular toxicity in human endothelian liver cancer (SK-hep1) cells, which proved completely resistant to the free drug.

NEAT1 upregulates TGF-β1 to induce hepatocellular carcinoma progression by sponging hsa-mir-139-5p.

Increasing evidence has shown that the lncRNA Nuclear Enriched Abundant Transcript 1 (NEAT1) play important roles in cell proliferation, migration, and invasion in various tumors. In our current study, we concentrated on the biological mechanisms of NEAT1 in hepatocellular carcinoma (HCC) development. It was found that NEAT1 was significantly increased in human HCC cell lines including Hep3B, LM3, MHCC97L, SK-hep1, and HepG2 cells compared to the normal human liver cell line LO2. Meanwhile, we observed that hsa-miR-139-5p was greatly decreased in HCC cells, which suggested a negative correlation between NEAT1 and hsa-mir-139-5p. In addition, NEAT1 downregulation can restrain HCC cell growth, migration, and invasion. Consistently, overexpression of hsa-mir-139-5p exerted a similar phenomenon. Dual-luciferase reporter assay, RIP assay, and RNA pull-down assay confirmed that NEAT1 can function as a ceRNA by sponging hsa-mir-139-5p. In addition, TGF-β1 was identified as a downstream target of hsa-mir-139-5p and hsa-mir-139-5p overexpression was able to suppress TGF-β1 levels. Furthermore, it was indicated that TGF-β1 inhibition can inhibit HCC cell growth, migration, and invasion ability. Taken these together, we speculated that NEAT1 can modulate TGF-β1 expression by sponging hsa-mir-139-5p in HCC. These data indicates that targeting the NEAT1/hsa-mir-139-5p/TGF-β1 axis could be a new strategy for HCC.