Comprehensive characterization of viral integrations and genomic aberrations in HBV-infected intrahepatic cholangiocarcinomas.

BACKGROUND AND AIMS: Despite the epidemiological association between intrahepatic cholangiocarcinoma (iCCA) and HBV infection, little is known about the relevant oncogenic effects. We sought to identify the landscape and mechanism of HBV integration, along with the genomic architecture of HBV-infected iCCA (HBV-iCCA) tumors. APPROACH AND RESULTS: We profiled a cohort of 108 HBV-iCCAs using whole-genome sequencing, deep sequencing, and RNA sequencing, together with preconstructed data sets of HBV-infected HCC (HBV-HCC; n = 167) and combined hepatocellular cholangiocarcinoma (HBV-cHCC/CCA; n = 59), and conventional (n = 154) and fluke-related iCCAs (n = 16). Platforms based on primary iCCA cell lines to evaluate the functional effects of chimeric transcripts were also used. We found that HBV had inserted at multiple sites in the iCCA genomes in 45 (41.7%) of the tumors. Recurrent viral integration breakpoints were found at nine different sites. The most common insertional hotspot (7 tumors) was in the TERT (telomerase reverse transcriptase) promoter, where insertions and mutations (11 tumors) were mutually exclusive, and were accompanied by promoter hyperactivity. Recurrent HBV integration events (5 tumors) were also detected in FAT2 (FAT atypical cadherin 2), and were associated with enrichment of epithelial-mesenchymal transition-related genes. A distinctive intergenic insertion (chr9p21.3), between DMRTA1 (DMRT like family A1) and LINC01239 (long intergenic non-protein coding RNA 1239), had oncogenic effects through activation of the mammalian target of rapamycin (mTOR)/4EBP/S6K pathway. Regarding the mutational profiles of primary liver cancers, the overall landscape of HBV-iCCA was closer to that of nonviral conventional iCCA, than to HBV-HCC and HBV-cHCC/CCA. CONCLUSIONS: Our findings provide insight into the behavior of iCCAs driven by various pathogenic mechanisms involving HBV integration events and associated genomic aberrations. This knowledge should be of use in managing HBV carriers.

Stabilization of E2-EPF UCP protein is implicated in hepatitis B virus-associated hepatocellular carcinoma progression.

Hepatitis B virus (HBV) X protein (HBx) is associated with hepatocarcinogenesis. E2-EPF ubiquitin carrier protein (UCP) catalyzes ubiquitination of itself and von Hippel-Lindau protein (pVHL) for degradation and associates with tumor growth and metastasis. However, it remains unknown whether HBx modulates the enzyme activity of UCP and thereby influences hepatocarcinogenesis. Here, we show that UCP is highly expressed in liver tissues of HBx-transgenic mice, but not non-transgenic mice. UCP was more frequently expressed in HBV-positive liver cancers than in HBV-negative liver cancers. HBx binds to UCP specifically and serotype independently, and forms a ternary complex with UCP and pVHL. HBx inhibits self-ubiquitination of UCP, but enhances UCP-mediated pVHL ubiquitination, resulting in stabilization of hypoxia-inducible factor-1α and -2α. HBx and UCP stabilize each other by mutually inhibiting their ubiquitination. HBx promotes cellular proliferation and metastasis via UCP. Our findings suggest that UCP plays a key role in HBV-related hepatocarcinogenesis.

Lipocalin 2 negatively regulates cell proliferation and epithelial to mesenchymal transition through changing metabolic gene expression in colorectal cancer.

Lipocalin 2 (LCN2), a member of the lipocalin superfamily, plays an important role in oncogenesis and progression in various types of cancer. However, the expression pattern and functional role of LCN2 in colorectal cancer (CRC) is still poorly understood. The purpose of the present study was to investigate whether LCN2 is associated with proliferation and the epithelial-mesenchymal transition (EMT) in CRC and to elucidate the underlying signaling pathways. LCN2 was preferentially expressed in CRC cells compared to normal tissues. However, LCN2 expression was significantly lower in metastatic or advanced-stage CRC than in non-metastatic or early stage CRC. Knockdown of LCN2 using small interfering RNA (siRNA) in CRC cells expressing a high level of LCN2 induced cell proliferation and a morphological switch from an epithelial to mesenchymal state. Furthermore, downregulation of LCN2 in CRC cells increased cell migration and invasion involved in the regulation of EMT markers. Knockdown of LCN2 also induced glucose consumption and lactate production, accompanied by an increase in energy metabolism-related genes. Taken together, our findings indicated that LCN2 negatively modulated proliferation, EMT and energy metabolism in CRC cells. Accordingly, LCN2 may be a candidate metastasis suppressor and potential therapeutic target in CRC.

Cancer related gene alterations can be detected with next-generation sequencing analysis of bile in diffusely infiltrating type cholangiocarcinoma.

Genome-wide association study in diffusely infiltrating type cholangiocarcinoma (CC) can be limited due to the difficulty of obtaining tumor tissue. We aimed to evaluate the genomic alterations of diffusely infiltrating type CC using next-generation sequencing (NGS) of bile and to compare the variations with those of mass-forming type CC. A total of 24 bile samples obtained during endoscopic retrograde cholangiopancreatography (ERCP) and 17 surgically obtained tumor tissue samples were evaluated. Buffy coat and normal tissue samples were used as controls for a somatic mutation analysis. After extraction of genomic DNA, NGS analysis was performed for 48 cancer related genes. There were 27 men and 14 women with a mean age of 65.0±11.8years. The amount of extracted genomic DNA from 3cm(3) of bile was 66.0±84.7µg and revealed a high depth of sequencing coverage. All of the patients had genomic variations, with an average number of 19.4±2.8 and 22.3±3.3 alterations per patient from the bile and tumor tissue, respectively. After filtering process, damaging SNPs (8 sites for each type of CC) were predicted by analyzing tools, and their target genes showed relevant differences between the diffusely infiltrating and mass-forming type CC. Finally, in somatic mutation analysis, tumor-normal paired 14 tissue and 6 bile samples were analyzed, genomic alterations of EGFR, FGFR1, ABL1, PIK3CA, and CDKN2A gene were seen in the diffusely infiltrating type CC, and TP53, KRAS, APC, GNA11, ERBB4, ATM, SMAD4, BRAF, and IDH1 were altered in the mass-forming type CC group. STK11, GNAQ, RB1, KDR, and SMO genes were revealed in both groups. The NGS analysis was feasible with bile sample and diffusely infiltrating type CC revealed genetic differences compared with mass-forming type CC. Genome-wide association study could be performed using bile sample in the patients with CC undergoing ERCP and a different genetic approach for accurate diagnosis, pathogenesis study, and targeted therapy will be needed in diffusely infiltrating type CC.

Statin pretreatment inhibits the lipopolysaccharide-induced epithelial-mesenchymal transition via the downregulation of toll-like receptor 4 and nuclear factor-κB in human biliary epithelial cells.

BACKGROUND AND AIM: Epithelial-mesenchymal transition (EMT) of biliary epithelial cells (BECs) plays an important role in biliary fibrosis. This study investigated the effects of simvastatin on the lipopolysaccharide (LPS)-induced EMT and related signal pathways in BECs. METHODS: Biliary epithelial cells were exposed to LPS (2 µg/mL) or transforming growth factor ß1 (TGF-ß1) (5 ng/mL) for 5 days. The EMT was assessed by a gain of mesenchymal cell markers (vimentin, N-cadherin, slug, and Twist-1) and a loss of epithelial cell markers (E-cadherin). The effects of simvastatin on the EMT induced by LPS or TGF-ß1 were determined by the changes in the levels of EMT markers and TLR4 and in the c-Jun N-terminal kinase (JNK), p38, and nuclear factor-κB (NF-κB) signaling pathways. RESULTS: Compared with the BECs treated with LPS alone, co-treatment with simvastatin and LPS induced an increase in the expression of E-cadherin and decreases in the expression levels of mesenchymal cell markers. The LPS-induced TLR4 expression level was slightly decreased by co-treatment with simvastatin. LPS-induced BEC growth was markedly inhibited by co-treatment with simvastatin. Furthermore, pretreatment with simvastatin inhibited the LPS-induced EMT in BECs by downregulating NF-κB and JNK phosphorylation. The suppressive effects of simvastatin pretreatment on the induction of the EMT by TGF-ß1 were also demonstrated in H69 cells. CONCLUSIONS: Our results demonstrate that LPS or TGF-ß1 promote the EMT in BECs that that pretreatment with simvastatin inhibited the induced EMT by downregulating toll-like receptor 4 and NF-κB phosphorylation. This finding suggests that simvastatin can be considered a new agent for preventing biliary fibrosis associated with the EMT of BECs.

Disruption of a regulatory loop between DUSP1 and p53 contributes to hepatocellular carcinoma development and progression.

BACKGROUND & AIMS: Altered expression of dual specificity phosphatase 1 (DUSP1) is common in tumors including hepatocellular carcinoma (HCC), and is predictive of tumor progression and poor prognosis. However, the tumor suppressive role of DUSP1 has yet to be clearly elucidated. METHODS: The molecular mechanisms of tumor suppression that were investigated were induction of apoptosis, cell cycle inhibition, and regulation of p53. Additionally, the antitumor effect of DUSP1 was assessed using a mouse model. Associated signaling pathways in HCC cells and tissues were examined. RESULTS: Downregulation of DUSP1 expression was significantly correlated with poor differentiation (p<0.001) and advanced HCC stage (p=0.023). DUSP1 expression resulted in HCC suppression and longer survival (p=0.0002) in a xenoplant mice model. DUSP1 inhibited p38 MAPK phosphorylation and subsequently suppressed HSP27 activation, resulting in enhanced p53 phosphorylation at sites S15, S20, and S46 in HCC cells. Enhanced p53 activation induced the expression of target genes p21 and p27, which are linked to cell cycle arrest and apoptosis. Thus, DUSP1 was potentially linked to p53 activation via the p38 MAPK/HSP27 pathway. Wild-type but not mutant p53 transcriptionally upregulated DUSP1 via its DNA-binding domain. DUSP1 and p53 might collaborate to suppress tumors in hepatocarcinogenesis via a positive regulatory loop. CONCLUSIONS: Our results revealed that disruption of a positive regulatory loop between DUSP1 and p53 promoted HCC development and progression, providing a rationale for a therapeutic agent that restores DUSP1 in HCC.

Accuracy of transient elastography in assessing liver fibrosis in chronic viral hepatitis: A multicentre, retrospective study.

BACKGROUND/AIMS: Transient elastography (TE) has become an alternative to liver biopsy (LB). This study investigated the diagnostic performance of liver stiffness (LS) measurement using TE in Korean patients with chronic hepatitis B and C (CHB and CHC). METHODS: From April 2006 to June 2014, 916 patients (567 CHB and 349 CHC) who underwent LB and TE at 15 centres were analyzed. The Batts and Ludwig scoring system was used for histologic assessment. Aspartate aminotransferase (AST)-to-platelet ratio indexes (APRI) were calculated. Area under the receiver operating characteristic curve (AUROC) was used. RESULTS: The median age, LS value, and APRI score were 45 years, 8.8 kPa, and 0.61, respectively, in CHB patients vs. 51 years, 6.8 kPa and 0.55, respectively, in CHC patients. TE was significantly superior to APRI in CHB patients (AUROC 0.774 vs. 0.72 for ≥F2, 0.849 vs. 0.812 for ≥F3, and 0.902 vs. 0.707 for F4, respectively; all P < 0.05). Furthermore, TE was significantly superior for predicting ≥ F3 stage (AUROC 0.865 vs. 0.840, P = 0.009) whereas it was similar for predicting ≥ F2 and F4 stage (AUROC 0.822 vs. 0.796; 0.910 vs. 0.884; all P > 0.05) in CHC patients. In CHB patients, optimal cut-off LS values were 7.8 kPa for ≥F2, 8.2 kPa for ≥ F3, and 11.6 kPa for F4, vs. 6.8 kPa, 8.6 kPa, and 14.5 kPa, respectively, in CHC patients. CONCLUSIONS: TE can accurately assess the degree of liver fibrosis in Korean patients with CVH. TE was superior to APRI for predicting each fibrosis stage.

Clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease.

Bacterial infection is an important cause of death in patients with liver cirrhosis. The aim of this study was to investigate the clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease (ALD). We retrospectively analyzed data from 409 patients consecutively admitted to a tertiary referral center with ALD diagnosis. Of a total of 544 admissions, 133 (24.4%) cases presented with bacterial infection, of which 116 were community-acquired whereas 17 were hospital-acquired. The common types of infection were pneumonia (38%), biliary tract infection (17%), soft tissue infection (12%), and spontaneous bacterial peritonitis (9%). Diabetes, serum Na <135 mM/L, albumin <2.5 g/dL, C-reactive protein ≥20 mg/L, systemic inflammatory response syndrome (SIRS) positivity were independently associated with bacterial infection in patients with ALD. Overall 30-day and 90-day mortalities in patients with bacterial infection were significantly (P < 0.001) higher than those without infection (22.3% vs. 5.1% and 32.3% vs. 8.2%, respectively). Furthermore, bacterial infection (HR, 2.2; 95% CI, 1.049-4.579, P = 0.037), SIRS positivity (HR, 2.5; 95% CI, 1.240-4.861, P = 0.010), Maddrey's discriminant function score ≥32 (HR, 2.3; 95% CI, 1.036-5.222, P = 0.041), and hemoglobin <12 g/dL (HR, 2.4; 95% CI, 1.081-5.450, P = 0.032) were independent predictors of short-term mortality. In conclusion, bacterial infection and SIRS positivity predicted short-term prognosis in hospitalized patients with ALD. A thorough evaluation at admission or on clinical deterioration is required to detect possible infection with prompt management.

Activation of mammalian target of rapamycin complex 1 (mTORC1) and Raf/Pyk2 by growth factor-mediated Eph receptor 2 (EphA2) is required for cholangiocarcinoma growth and metastasis.

Eph receptor 2 (EphA2) overexpression is frequently accompanied by the loss of its cognate ligand during tumor progression. However, the molecular mechanism of this ligand-independent promotion of tumor by EphA2 remains unclear in highly malignant and fatal cholangiocarcinoma (CC). We examined the biological role of EphA2 in tumor growth and metastasis in CC tissues and cells according to the degree of differentiation and we explored the downstream signaling pathways of EphA2. Growth factor-mediated EphA2 overexpression itself leads to the activation of the mammalian target of rapamycin complex 1 (mTORC1) and extracellular signal-regulated kinase (ERK) pathways through ligand-independent activation of EphA2 (phosphorylation of S897). An in vitro soft agar assay and in vivo orthotopic or subcutaneous tumor model showed that EphA2 enhanced colony formation and accelerated tumor growth, and which seemed to be mainly associated with Akt (T308)/mTORC1 activation. Aberrant expression and activation of EphA2 was also associated with poorer differentiation and higher metastatic ability. Enhanced metastatic ability was also observed in an orthotopic tumor model or lung metastasis model, correlating with Pyk2(Y402)/c-Src/ERK activation in addition to activation of the canonical Raf/MEK/ERK pathway. The mTORC1 and Raf/Pyk2 pathways also appeared to affect each other. These results suggest that growth factor-mediated EphA2 might be involved in tumor growth and metastasis through activation of the mTORC1 and Raf/Pyk2 pathways. Therapeutic strategies that target EphA2 and its downstream effectors may be useful to control CC. (HEPATOLOGY 2013;57:2248-2260).

Lipocalin-2 negatively modulates the epithelial-to-mesenchymal transition in hepatocellular carcinoma through the epidermal growth factor (TGF-beta1)/Lcn2/Twist1 pathway.

UNLABELLED: Lipocalin-2 (Lcn2) is preferentially expressed in hepatocellular carcinoma (HCC). However, the functional role of Lcn2 in HCC progression is still poorly understood, particularly with respect to its involvement in invasion and metastasis. The purpose of this study was to investigate whether Lcn2 is associated with the epithelial-mesenchymal transition (EMT) in HCC and to elucidate the underlying signaling pathway(s). Lcn2 was preferentially expressed in well-differentiated HCC versus liver cirrhosis tissues, and its expression was positively correlated with the stage of HCC. The characteristics of EMT were reversed by adenoviral transduction of Lcn2 into SH-J1 cells, including the down-regulation of N-cadherin, vimentin, alpha-smooth muscle actin, and fibronectin, and the concomitant up-regulation of CK8, CK18, and desmoplakin I/II. Knockdown of Lcn2 by short hairpin RNA (shRNA) in HKK-2 cells expressing high levels of Lcn2 was associated with EMT. Epidermal growth factor (EGF) or transforming growth factor beta1 (TGF-ß1) treatment resulted in down-regulation of Lcn2, accompanied by an increase in Twist1 expression and EMT in HCC cells. Stable Lcn2 expression in SH-J1 cells reduced Twist1 expression, inhibited cell proliferation and invasion in vitro, and suppressed tumor growth and metastasis in a mouse model. Furthermore, EGF or TGF-ß1 treatment barely changed EMT marker expression in SH-J1 cells ectopically expressing Lcn2. Ectopic expression of Twist1 induced EMT marker expression even in cells expressing Lcn2, indicating that Lcn2 functions downstream of growth factors and upstream of Twist1. CONCLUSION: Together, our findings indicate that Lcn2 can negatively modulate the EMT in HCC cells through an EGF (or TGF-ß1)/Lcn2/Twist1 pathway. Thus, Lcn2 may be a candidate metastasis suppressor and a potential therapeutic target in HCC.

Endoscopic stenting in bile duct cancer increases liver volume.

BACKGROUND: Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malignant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied. OBJECTIVE: We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents. DESIGN: Retrospective review. SETTING: University hospital. PATIENTS: Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting. INTERVENTIONS: ERCP with self-expandable metal stent placement. MAIN OUTCOME MEASUREMENTS: Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral). RESULTS: There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for unilateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7 ± 4.9 weeks. Liver volume increased 17.4 ± 24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P = .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P = .512). LIMITATIONS: Single center, retrospective. CONCLUSIONS: Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy.

Long-term efficacy of entecavir plus adefovir combination therapy versus entecavir monotherapy in adefovir refractory chronic hepatitis B patients with prior lamivudine resistance.

OBJECTIVES: We investigated the long-term efficacy of entecavir (ETV) + adefovir (ADV) combination therapy versus ETV monotherapy in lamivudine (LAM)-resistant chronic hepatitis B (CHB) patients who failed to respond to ADV rescue therapy. METHODS: A total of 91 ADV refractory patients with prior LAM resistance received ETV (1.0 mg/day) + ADV (10 mg/day) combination therapy (group A, n = 45) or ETV (1.0 mg/day) monotherapy (group B, n = 46) for more than 48 weeks. RESULTS: The rates of undetectable serum hepatitis B virus DNA levels (≤20 IU/ml) at weeks 48 and 96 were not significantly different between group A and group B (31.1 vs. 23.9% at week 48, p = 0.442, and 44.7 vs. 34.5% at week 96, p = 0.457). However, the incidence of virological breakthrough in group A was significantly lower than that in group B (0 vs. 17.4% at week 48, p = 0.006, and 2.6 vs. 44.8% at week 96, p < 0.001). ETV monotherapy was the only independent factor significantly associated with virologic breakthrough (p = 0.015). CONCLUSIONS: ETV + ADV combination therapy is a better therapeutic option than ETV monotherapy for ADV refractory CHB patients with prior LAM resistance.

4-Substituted quinazoline derivatives as novel EphA2 receptor tyrosine kinase inhibitors.

Erythropoietin-producing hepatocellular receptor tyrosine kinase subtype A2 (EphA2) is an attractive therapeutic target for suppressing tumor progression. In our efforts to discover novel small molecules to inhibit EphA2, a class of compound based on 4-substituted quinazoline containing 7-(morpholin-2-ylmethoxy) group was identified as a novel hit by high throughput screening campaign. Structural modification of parent quinazoline scaffolds by introducing substituents on aniline displayed potent inhibitory activities toward EphA2.

Sixty-five gene-based risk score classifier predicts overall survival in hepatocellular carcinoma.

UNLABELLED: Clinical application of the prognostic gene expression signature has been delayed due to the large number of genes and complexity of prediction algorithms. In the current study we aimed to develop an easy-to-use risk score with a limited number of genes that can robustly predict prognosis of patients with hepatocellular carcinoma (HCC). The risk score was developed using Cox coefficient values of 65 genes in the training set (n = 139) and its robustness was validated in test sets (n = 292). The risk score was a highly significant predictor of overall survival (OS) in the first test cohort (P = 5.6 × 10(-5), n = 100) and the second test cohort (P = 5.0 × 10(-5) , n = 192). In multivariate analysis, the risk score was a significant risk factor among clinical variables examined together (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.13-1.64; P = 0.001 for OS). CONCLUSION: The risk score classifier we have developed can identify two clinically distinct HCC subtypes at early and late stages of the disease in a simple and highly reproducible manner across multiple datasets.

The successful endoscopic hemostasis factors in bleeding from advanced gastric cancer.

BACKGROUND: When patients with advanced gastric cancer experience active bleeding, gastroenterologists normally choose between two treatment modalities, endoscopic hemostasis and transarterial embolization (TAE). In patients with advanced gastric cancer with bleeding, the predictive factors for endoscopic hemostatic failure are still unknown. Thus, the purpose of this study was to evaluate predictive factors for endoscopic hemostasis failure and to differentiate which hemostasis procedure is more effective for advanced gastric cancer with bleeding. METHODS: We reviewed the medical records of patients who were diagnosed with advanced gastric cancer and acute non-variceal gastric bleeding from January 2006 to August 2011. Forty-five patients were enrolled in this study and they were divided into a group of 14 patients who had experienced successful endoscopic hemostasis and a group of 31 patients who had had unsuccessful hemostasis with the first endoscopy and then underwent TAE. RESULTS: Lesion size and bleeding condition of Forrest class 1a or 1b were statistically significant predictive factors for endoscopic hemostatic failure (P = 0.023 and P = 0.017, respectively). On multivariate logistic regression analysis, size (lesion >2 cm) was a significant predictive factor for endoscopic hemostatic failure [adjusted odds ratio (aOR) 8.056; 95% confidence interval (CI) 1.329-48.846]. CONCLUSIONS: We determined that small bleeding lesions (<2 cm) and exposed vessels in the bleeding site with gastric cancer indicated that endoscopic hemostasis would be an effective hemostatic modality to choose. Particularly, in the opposite condition, the presence of large bleeding lesions (>2 cm) and non-exposed vessel bleeding with a tumor, endoscopic hemostasis failure is predicted and TAE could be recommended.

Robust and multifunctional nanosheath for chemical and biological nanodevices.

The contribution of advanced nanoscale chemical and biological devices to life science has been limited to a small number of nanomaterials, due to the absence of effective surface modification routes. Herein, we demonstrate a polymer-like nanosheath synthesized by nonthermal plasma technology (NPT) that can protect the core nanomaterial from the solution environment and provide a multifunctional platform for chemical and biological nanosensors. For ZnO nanowires (NWs) which are unstable in solution, we demonstrate that this nanosheath makes it possible for ZnO NW field-effect transistors to act as a pH sensor for 24 h and a biosensor for the real-time, label-free detection of liver cancer markers.

Hepatitis B virus X protein regulates hepatic glucose homeostasis via activation of inducible nitric oxide synthase.

Dysregulation of liver functions leads to insulin resistance causing type 2 diabetes mellitus and is often found in chronic liver diseases. However, the mechanisms of hepatic dysfunction leading to hepatic metabolic disorder are still poorly understood in chronic liver diseases. The current work investigated the role of hepatitis B virus X protein (HBx) in regulating glucose metabolism. We studied HBx-overexpressing (HBxTg) mice and HBxTg mice lacking inducible nitric oxide synthase (iNOS). Here we show that gene expressions of the key gluconeogenic enzymes were significantly increased in HepG2 cells expressing HBx (HepG2-HBx) and in non-tumor liver tissues of hepatitis B virus patients with high levels of HBx expression. In the liver of HBxTg mice, the expressions of gluconeogenic genes were also elevated, leading to hyperglycemia by increasing hepatic glucose production. However, this effect was insufficient to cause systemic insulin resistance. Importantly, the actions of HBx on hepatic glucose metabolism are thought to be mediated via iNOS signaling, as evidenced by the fact that deficiency of iNOS restored HBx-induced hyperglycemia by suppressing the gene expression of gluconeogenic enzymes. Treatment of HepG2-HBx cells with nitric oxide (NO) caused a significant increase in the expression of gluconeogenic genes, but JNK1 inhibition was completely normalized. Furthermore, hyperactivation of JNK1 in the liver of HBxTg mice was also suppressed in the absence of iNOS, indicating the critical role for JNK in the mutual regulation of HBx- and iNOS-mediated glucose metabolism. These findings establish a novel mechanism of HBx-driven hepatic metabolic disorder that is modulated by iNOS-mediated activation of JNK.

Vitamin D3 upregulated protein 1 suppresses TNF-α-induced NF-κB activation in hepatocarcinogenesis.

Vitamin D(3) upregulated protein 1 (VDUP1) is a candidate tumor suppressor, the expression of which is dramatically reduced in various tumor tissues. In this study, we found that VDUP1 expression is suppressed during human hepatic carcinogenesis, and mice lacking VDUP1 are much more susceptible to diethylnitrosamine-induced hepatocarcinogenesis compared with wild type mice. VDUP1-deficient tumors proliferated significantly more than wild type tumors and had corresponding changes in the expression of key cell cycle regulatory proteins. In addition, the hepatomitogen-induced response was associated with a considerable increase in the release of TNF-α and subsequent enhancement of NF-κB activation in VDUP1-deficient mice. When cells were treated with TNF-α, the VDUP1 level was markedly reduced, concomitant with elevated NF-κB activation. Furthermore, the overexpression of VDUP1 resulted in the robust suppression of TNF-α-activated NF-κB activity via association with HDAC1 and HDAC3. These results indicate that VDUP1 negatively regulates hepatocarcinogenesis by suppressing TNF-α-induced NF-κB activation.

Acquisition of chemoresistance in intrahepatic cholangiocarcinoma cells by activation of AKT and extracellular signal-regulated kinase (ERK)1/2.

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignant tumor and is refractory to conventional chemotherapy. The aim of this study is therefore to elucidate the mechanism of chemoresistance in ICC which is not fully understood. We generated cisplatin resistant ICC cells via long term exposure to cisplatin and found that these cells are also resistant to 5-fluorouracil (5-FU) and gemcitabine. The chemoresistant cells showed enhanced Bcl-2 expression and reduced Bax expression compared to parental ICC cells. In addition, the resistant cells showed enhanced activation of AKT and extracellular signal-regulated kinase (ERK) 1/2. Inhibition of AKT activation by phosphoinocitide 3-kinase (PI3K) inhibitor LY294002 resulted in reduced Bcl-2 expression and enhanced Bax expression and thus induced apoptosis in the resistant cells, whereas inhibition of ERK1/2 activation by mitogen-activated protein kinase (MEK) inhibitor U0126 did not induce apoptosis without affecting the expression of Bcl-2 and Bax but decreased cell growth. Moreover, the inhibition of AKT or ERK1/2 sensitized the resistant cells to cisplatin and therefore resulted in greatly enhanced cisplatin-induced apoptosis and growth inhibition in the cells. The results indicate that AKT and ERK1/2 signaling mediate chemoresistance in the cells and could be important therapeutic targets for overcoming chemoresistance in ICC.

Genome-wide expression patterns associated with oncogenesis and sarcomatous transdifferentation of cholangiocarcinoma.

BACKGROUND: The molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation. METHODS: Genes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells. RESULTS: Using unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (<0.5 fold change). Expression of SPP1, EFNB2, E2F2, IRX3, PTTG1, PPARγ, KRT17, UCHL1, IGFBP7 and SPARC proteins was immunohistochemically verified in human and hamster CC tissues. Additional unsupervised hierarchical clustering analysis of sarcomatoid CC cells compared to three adenocarcinomatous CC cell lines revealed 292 differentially upregulated genes (>4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC. CONCLUSION: The deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis.