Transgenic Mouse Model Of Hepatocellular Carcinoma Research Articles

Hepatocyte transformation is induced by laminin γ2 monomer.

Serum laminin-γ2 monomer (Lm-γ2m) is a potent predictive biomarker for hepatocellular carcinoma (HCC) onset in patients with hepatitis C infection who achieve a sustained virologic response with liver cirrhosis (LC) and for the onset of extrahepatic metastases in early-stage HCC. Although Lm-γ2m involvement in late-stage cancer progression has been well investigated, its precise roles in HCC onset remain to be systematically investigated. Therefore, we analyzed an HCC model, human hepatocytes and cholangiocytes, and surgically resected liver tissues from patients with HCC to understand the roles of Lm-γ2m in HCC onset. Ck-19- and EpCAM-positive hepatic progenitor cells (HPCs) in the liver of pdgf-c transgenic HCC mouse model with ductular reaction showed ectopic expression of Lm-γ2m. Forced expression of Lm-γ2m in hepatocytes adjacent to HPCs resulted in enhanced tumorigenicity, cell proliferation, and migration in immortalized hepatocytes, but not in cholangiocytes invitro. Further, pharmacological inhibition of epidermal growth factor receptor (EGFR) and c-Jun activator JNK suppressed Lm-γ2m-induced hepatocyte transformation, suggesting the involvement of EGFR/c-Jun signaling in the transformation, leading to HCC development. Finally, immunohistochemical staining of HCC tissues revealed a high level of Lm-γ2 expression in the HPCs of the liver with ductular reaction in normal liver adjacent to HCC tissues. Overall, HPC-derived Lm-γ2m in normal liver with ductular reaction acts as a paracrine growth factor on surrounding hepatocytes and promotes their cellular transformation through the EGFR/c-Jun signaling pathway. Furthermore, this is the first report on Lm-γ2m expression detected in the normal liver with ductular reaction, a human precancerous lesion of HCC.

Bromo- and extraterminal domain protein inhibition improves immunotherapy efficacy in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) represents the majority of liver cancer and is the fourth most common cause of cancer‐related death. Although advances in molecular targeted therapy have shown promise, none of these agents has yet demonstrated significant clinical benefit. Bromo‐ and extraterminal domain (BET) protein inhibitors have been considered potential therapeutic drugs for HCC but the biological activity remains unclear. This study found that BET protein inhibition did not effectively suppress the progression of HCC, using a transgenic HCC mouse model. Mechanistically, the BET protein inhibitor JQ1 upregulated the expression of programmed cell death‐ligand 1 (PD‐L1) on the plasma membrane in vivo and in vitro. Moreover, JQ1 enhanced the expression of Rab8A, which upregulated the expression of PD‐L1 on the plasma membrane. This study also showed that JQ1 combined with anti‐PD‐L1 Ab effectively suppressed HCC progression, and this benefit was obtained by enhancing the activation and cytotoxic capabilities of CD8 T cells. These results revealed the crucial role and regulation of BET protein inhibition on the expression of PD‐L1 in HCC. Thus, combining BET protein inhibition with immune checkpoint blockade offers an efficient therapeutic approach for HCC.

Abstract 1636: Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B)

Abstract Background: Non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) is a chronic liver disease commonly associated with hepatic fibrosis. NASH patients have an increased risk for hepatocellular carcinoma (HCC). Due to western way of life, NASH incidence is rising and predicted to become the leading cause of liver transplant in 2020 and of HCC in the next decades. There is an urgent need for robust animal models fully recapitulating the NASH-related HCC carcinogenesis due to this changing in HCC etiology. In this study, we develop and characterize specific diet-induced variants from our transgenic HCC mouse model, focusing on immune landscape. Methods: We used in the whole study ASV-B mice: a transgenic mouse model (C57BL/6J) spontaneously developing a reproducible stage-defined HCC (hyperplasia at week(W)8, nodular stage at W12, and diffuse carcinoma at W16-20). Livers were characterized for angiogenesis and immune populations using immunostaining (IHC and IF), and qRT-PCR (LightCycler, Roche). To mimic NASH, ASV-B mice were exposed to 5 different diets. Ten ASV-B and 5 control mice were fed as follows: classic diet as control (yellow), or a high-fat diet (blue), a diet enriched with saturated fatty acids + 1.25% cholesterol (green), a diet containing 22% of vegetal oil + 0.2% cholesterol (orange), and a 1.25% cholesterol diet containing 21% of milkfat (red). All mice fed with special diets also received 30% fructose in the drink water. A second experiment was performed on ASV-B and C57BL/6J wild type mice, using control and Nash-inducing regimen, to confirm our first results. Results: ASV-B model showed an increase in liver volume and angiogenesis, HCC livers harboring marked arterialization and capillarization as compared to control. Assessing immune markers on 7 evaluable tumor specimens, we observed an increase in CD8, Foxp3, INOS, CD11b, PD-1, PD-L1, IL1β, IFN-γ, TNF-α, IL17A and IL17F mRNA expressions, as frequently observed in human inflammatory HCC. In addition, IHC staining showed intratumoral infiltration of lymphocytes (CD8+) and macrophages (F4/80+, a well-characterized and extensively referenced mouse macrophage marker). ASV-B mice receiving yellow, blue, and green regimens showed similar liver volumes and weights. By macroscopic analysis, we observed increased liver steatosis, and fibrosis in the red and orange regimen compared to others. Moreover, we observed a 40% mortality rate in the orange regimen, and a 20% mortality rate in the blue and green regimens. Interestingly, by microscopic analysis, we observed liver steatosis and inflammation, in 100%, and 75% of the mice, respectively. These results indicate that the green regimen is the most suitable to induce NASH-underlyning disease in our transgenic HCC model. At the conference, we will show in the diet-variants, the immune landscape of the livers and the results of our ongoing second experiment. Conclusion: ASV-B transgenic mouse model mimics several characteristics of human HCC developing on healthy liver including inflammatory reaction and immune cell infiltration. In the ASV-B model, we have been able to develop specific-diets variants mimicking NASH characteristics that could be used for drug testing. Citation Format: Annemilaï Tijeras-Raballand, Christian Hobeika, Philippe Bonnin, Benoit Rousseau, Aurélie Rodrigues, Fouad Ladfil, Marc Pocard, Armand de Gramont, Eric Raymond, Sandrine Faivre, Valérie Paradis, Clarisse Eveno. Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1636.

Macrophages protect against loss of adipose tissue during cancer cachexia.

BackgroundCancer cachexia represents a central obstacle in medical oncology as it is associated with poor therapy response and reduced overall survival. Systemic inflammation is considered to be a key driver of cancer cachexia; however, clinical studies with anti‐inflammatory drugs failed to show distinct cachexia‐inhibiting effects. To address this contradiction, we investigated the functional importance of innate immune cells for hepatocellular carcinoma (HCC)‐associated cachexia.MethodsA transgenic HCC mouse model was intercrossed with mice harbouring a defect in myeloid cell‐mediated inflammation. Body composition of mice was analysed via nuclear magnetic resonance spectroscopy and microcomputed tomography. Quantitative PCR was used to determine adipose tissue browning and polarization of adipose tissue macrophages. The activation state of distinct areas of the hypothalamus was analysed via immunofluorescence. Multispectral immunofluorescence imaging and immunoblot were applied to characterize sympathetic neurons and macrophages in visceral adipose tissue. Quantification of pro‐inflammatory cytokines in mouse serum was performed with a multiplex immunoassay. Visceral adipose tissue of HCC patients was quantified via the L3 index of computed tomography scans obtained during routine clinical care.ResultsWe identified robust cachexia in the HCC mouse model as evidenced by a marked loss of visceral fat and lean mass. Computed tomography‐based analyses demonstrated that a subgroup of human HCC patients displays reduced visceral fat mass, complementing the murine data. While the myeloid cell‐mediated inflammation defect resulted in reduced expression of pro‐inflammatory cytokines in the serum of HCC‐bearing mice, this unexpectedly did not translate into diminished but rather enhanced cachexia‐associated fat loss. Defective myeloid cell‐mediated inflammation was associated with decreased macrophage abundance in visceral adipose tissue, suggesting a role for local macrophages in the regulation of cancer‐induced fat loss.ConclusionsMyeloid cell‐mediated inflammation displays a rather unexpected beneficial function in a murine HCC model. These results demonstrate that immune cells are capable of protecting the host against cancer‐induced tissue wasting, adding a further layer of complexity to the pathogenesis of cachexia and providing a potential explanation for the contradictory results of clinical studies with anti‐inflammatory drugs.

Abstract 91: Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B)

Abstract Background: Non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) is a chronic liver disease commonly associated with hepatic fibrosis. NASH patients have an increased risk for hepatocellular carcinoma (HCC). Due to western way of life, NASH incidence is rising and is predicted to become the leading cause of HCC in the next decades. Therefore, there is an urgent need for robust animal models fully recapitulating the NASH-related HCC carcinogenesis. In this study, we develop and characterize specific diet-induced variants from our transgenic HCC mouse model, focusing on immune landscape. Methods: To mimic NASH, ASV-B, a transgenic mouse model (C57BL/6J) that spontaneously develops a reproducible stage-defined HCC (hyperplasia at week(W)8, nodular stage at W12, and diffuse carcinoma at W16-20) was exposed to 5 different diets. Ten ASV-B and 5 control mice were fed as follows: classic diet as control (yellow), or a high-fat diet (blue), a diet enriched with saturated fatty acids + 1.25% cholesterol (green), a diet containing 22% of vegetal oil + 0.2% cholesterol (orange), and a 1.25% cholesterol diet containing 21% of milkfat (red). All mice fed with special diets also received 30% fructose in the drink water. RNA was extracted from frozen livers at W20 for 40 immune markers analysis using qRT-PCR (LightCycler, Roche). Immune populations were assessed using automated immunohistochemistry (IHC) (Bond Max, Leica). Results: ASV-B model shows an increase in liver volume and angiogenesis, ASV-B livers harboring marked arterialization and capillarization as compared to control. Assessing immune markers on 7 evaluable tumor specimens, we observed an increase in CD8, Foxp3, INOS, CD11b, PD-1, PD-L1, IL1β, IFN-γ, TNF-α, IL17A and IL17F mRNA expression, as frequently observed in human inflammatory HCC. In addition, IHC staining showed intratumoral infiltration of lymphocytes (CD8+) and macrophages (F4/80+, a well-characterized and extensively referenced mouse macrophage marker). ASV-B mice receiving yellow, blue, and green regimens showed similar liver volumes and weight. By macroscopic analysis, we observed increased liver steatosis, and fibrosis in the red and orange regimen compared to others. Moreover, we observed a 40% mortality rate in the orange regimen, and a 20% mortality rate in the blue and the green regimens. At the conference, we will show the morphologic changes of the livers using HPS staining and the immune landscape in the livers of the diet-variants. Conclusion: ASV-B transgenic mouse model mimics several characteristics of human HCC developing on healthy liver including inflammatory reaction and immune cell infiltration. In the ASV-B model, we have been able to develop specific-diets variants aiming at mimicking NASH that could be used for drug testing. Citation Format: Annemilaï Tijeras-Raballand, Christian Hobeika, Benoit Rousseau, Patricia Hainaud, Philippe Bonnin, Aurélie Rodrigues, Fouad Ladfil, Marc Pocard, Valérie Paradis, Armand de Gramont, Eric Raymond, Evelyne Dupuy, Clarisse Eveno, Sandrine Faivre. Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 91.

Toll-like receptor 3 downregulation is an escape mechanism from apoptosis during hepatocarcinogenesis

Low levels of toll-like receptor 3 (TLR3) in patients with hepatocellular carcinoma (HCC) are associated with poor prognosis, primarily owing to the loss of inflammatory signaling and subsequent lack of immune cell recruitment to the liver. Herein, we explore the role of TLR3-triggered apoptosis in HCC cells. Quantitative reverse transcription PCR, western blotting, immunohistochemistry and comparative genomic hybridization were used to analyze human and mouse HCC cell lines, as well as surgically resected primary human HCCs, and to study the impact of TLR3 expression on patient outcomes. Functional analyses were performed in HCC cells, following the restoration of TLR3 by lentiviral transduction. The role of TLR3-triggered apoptosis in HCC was analyzed in vivo in a transgenic mouse model of HCC. Lower expression of TLR3 in tumor compared to non-tumor matched tissue was observed at both mRNA and protein levels in primary HCC, and was predictive of shorter recurrence-free survival after surgical resection in both univariate (hazard ratio [HR] 1.79; 95% CI 1.04-3.06; p = 0.03) and multivariate analyses (HR 1.73; CI 1.01-2.97; p = 0.04). Immunohistochemistry confirmed frequent downregulation of TLR3 in human and mouse primary HCC cells. None of the 6 human HCC cell lines analyzed expressed TLR3, and ectopic expression of TLR3 following lentiviral transduction not only restored the inflammatory response but also sensitized cells to TLR3-triggered apoptosis. Lastly, in the transgenic mouse model of HCC, absence of TLR3 expression was accompanied by a lower rate of preneoplastic hepatocyte apoptosis and accelerated hepatocarcinogenesis without altering the tumor immune infiltrate. Downregulation of TLR3 protects transforming hepatocytes from direct TLR3-triggered apoptosis, thereby contributing to hepatocarcinogenesis and poor patient outcome. Hepatocellular carcinoma (HCC) is a heterogeneous disease associated with a poor prognosis. In patients with HCC, TLR3 downregulation is associated with reduced survival. Herein, we show that the absence of TLR3 is associated with a lower rate of apoptosis, and subsequently more rapid hepatocarcinogenesis, without any change to the immune infiltrate in the liver. Therefore, the poor prognosis associated with low TLR3 expression in HCC is likely linked to tumors ability to escape apoptosis. TLR3 may become a promising therapeutic target in TLR3-positive HCC.

Abstract B145: Addition of galunisertib to DC101 improved angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC)

Abstract Introduction: Galunisertib, a selective ATP-mimetic TGF-β receptor (TGFβR)-I inhibitor, displays a very safe toxicity profile in clinical trials, making it suitable for combinations. Galunisertib showed activity as second-line treatment in advanced HCC patients with high baseline AFP > 200 ng/mL. Patients experiencing >20% reduction in AFP level during treatment with galunisertib presented an outstanding median overall survival of 21.4 months (Faivre et al., ASCO GI 2014). Poor-prognosis HCC patients require innovative combinations to improve outcomes observed with antiangiogenic therapies. DC101 is a rat antagonist antibody to mouse VEGFR-2, and is used to model VEGFR-2 blockade in murine model. Both therapies have been shown to be independently beneficial to some subpopulation of HCC patients. Our study aimed at exploring the antitumoral potency of a combination of galunisertib and DC101 in an in vivo transgenic mouse model of HCC. Materials and Methods: Transgenic mice developing stage-defined HCC were treated for 8 weeks (W) from W8 to W16 with either vehicle, DC101 (40mg/kg, twice weekly, IP), galunisertib (100mg/kg, daily, oral gavage), or DC101 plus galunisertib. Tumor growth was evaluated by ultrasound (liver size) and by the number of macronodules at sacrifice. Angiogenesis was evaluated by Doppler (blood flow in the coeliac trunk) and by CD31 staining. Results: First, we confirmed the mode of action of galunisertib by assessing pSMAD2 expression, the pharmacodynamics target of galunisertib, before and after treatment. An 87% decrease in pSMAD2 expression was observed in liver tumors treated by galunisertib compared to placebo or DC101. Liver size and the number of liver tumor macronodules were significantly lower in all treatment arms compared to placebo control at both the W12 intermediary sacrifice and W16 final sacrifice; the combination of galunisertib and DC101 improved tumor control at W16 in the combination arm (4.43 mm3±0,55 mean liver volume) vs in the DC101, galunisertib, and placebo arms (5.22±0,86, 5.68±0,78, 7.09±1,54 respectively). Tumor growth inhibition was confirmed at W16 by a 31% and 52% decrease in the number of macronodules compared to placebo, in the galunisertib- and DC101-treated mice, respectively. This inhibition reached 62% in the combination group compared to placebo. Moreover, on hematoxylin phloxine saffron (HPS) section, no decrease in the number of micronodules was observed, whereas the size of these micronodules was dramatically reduced, especially in the combination arm with a 72% decrease compared to placebo. Angiogenesis, assessed by measuring the mean blood flow in the coeliac trunk (TCm), decreased in all treatment arms compared to placebo. At W16, galunisertib potentiated the effect of DC101 with a TCm decrease of 66% compared to 59% and 10% in the DC101 and galunisertib arms, respectively. CD31 confirmed the antiangiogenic effects of galunisertib and DC101, with a 25% and 51% decrease in vessel number, respectively, compared to placebo. These effects on angiogenesis were potentiated in the combination arm with an 80% decrease compared to placebo. Conclusion: The combination of galunisertib and DC101 showed promising antitumor activities that were associated with decreased angiogenesis. Citation Format: Annemilai Tijeras-Raballand, Christian Hobeika, Matthieu Martinet, Elise Paven, Philippe Bonin, Clarisse Eveno, Marc Pocard, Mohamed Bouattour, Sandrine Faivre, Eric Raymond, Armand de Gramont. Addition of galunisertib to DC101 improved angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC) [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B145.

Abstract 321: S49076, a novel kinase inhibitor of MET, AXL and FGFR, demonstrates marked in vitro and in vivo efficacy in hepatocellular carcinoma

Abstract Introduction: Hepatocellular carcinoma (HCC) is the second cause of cancer-related deaths worldwide. While sorafenib may improve overall survival in advanced HCC, new therapies are needed. Both preclinical and clinical data support a role of MET and AXL receptor tyrosine kinases in HCC progression. We thus evaluated S49076, a novel MET/AXL/FGFR inhibitor in HCC cell lines in vitro and in a transgenic mouse model of HCC. Materials and Methods: MET and AXL expressions were assessed in a panel of HCC cell lines by western blot. Downstream signaling pathways were investigated in the presence of HGF, GAS6 and S49076. Cell invasion was evaluated on matrigel assay. Transgenic mice developing stage-defined HCC were treated with S49076 (50mg/kg). Tumor response was evaluated measuring liver volume by echo-doppler and the number of tumor nodules at intermediary (12weeks) and final sacrifice (16 weeks). Results: Both MET and AXL are expressed in the majority of HCC lines screened. Notably, a high level of AXL was observed in the SK-HEP1 cells which were therefore selected for further investigation. MET and AXL pathways were strongly stimulated by their respective ligands, HGF and GAS6. Combination of HGF and GAS6 led to marked activation of ERK. S49076 inhibited MET and AXL pathway activation and HGF- and GAS6- induced invasion at nanomolar concentrations. In vivo anti-tumor efficacy of S49076 was demonstrated in a transgenic MET-expressing mouse model of HCC. Conclusion: S49076 displayed strong MET and AXL pathway inhibition and anti-invasive properties in SK-HEP1 HCC cells. Moreover, S49076 demonstrated antitumor activity in a mouse model of HCC. Together, these results would support development of S49076 as an innovative treatment in HCC patients. Citation Format: Annemilai Tijeras-Raballand, Adrien Pasteur-Rousseau, Matthieu Martinet, Philippe Bonnin, Marc Pocard, Sébastien Banquet, Valérie Cattan, Eric Raymond, Armand de Gramont. S49076, a novel kinase inhibitor of MET, AXL and FGFR, demonstrates marked in vitro and in vivo efficacy in hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 321.

Development of a transgenic mouse model of hepatocellular carcinoma with a liver fibrosis background.

BackgroundLiver fibrosis and its end-stage disease, cirrhosis, are major risk factors for hepatocellular carcinoma (HCC) and present in 80 to 90 % of patients with HCC. Current genetically engineered mouse models for HCC, however, generally do not feature liver fibrosis, which is a critical discrepancy between human HCC and murine models thereof. In this study, we developed a simple transgenic mouse model of HCC within the context of a fibrotic liver.MethodsEmploying hydrodynamic transfection (HT), coupled with the Sleeping Beauty (SB) transposon system, liver was stably transfected with transposons expressing cMyc and a short hairpin RNA down-regulating p53 (shp53). A chronic liver injury model, induced by hepatotoxic carbon tetrachloride (CCl4), was applied to the transgenic mice, allowing cells expressing cMyc plus shp53 to become malignant in the background of liver fibrosis.ResultsLivers harvested about 3 months after HT had excessive collagen deposition and activated hepatic stellate cells surrounding the tumors. Hepatocarcinogenesis was significantly accelerated in the fibrotic livers compared to those of the control, significantly decreasing the life span of the mice. The tumor incidence and average number of tumors per mouse were significantly higher in the group treated with CCl4 compared to the vehicle-treated control mice, following HT (p < 0.01).ConclusionsConsidering the simplicity and efficiency in generating HCC for fibrotic livers, the transgenic HCC model has the potential to be effectively used in preclinical testing of HCC anticancer therapy and in studies of hepatocarcinogenesis in fibrotic livers.Electronic supplementary materialThe online version of this article (doi:10.1186/s12876-016-0423-6) contains supplementary material, which is available to authorized users.

Preclinical Assessment of the Efficacy of Anti-Angiogenic Therapies in Hepatocellular Carcinoma

Diffuse hepatocellular carcinoma (HCC) is a complex affliction in which comorbidities can bias global outcome of cancer therapy. Better methods are thus warranted to directly assess effects of therapy on tumor angiogenesis and growth. As tumor angiogenesis is invariably associated with changes in local blood flow, we assessed the utility of ultrasound imaging in evaluation of the efficacy of anti-angiogenic therapy in a spontaneous transgenic mouse model of HCC. Blood flow velocities were measured monthly in the celiac trunk before and after administration of sorafenib or bevacizumab at doses corresponding to those currently used in clinical practice. Concordant with clinical experience, sorafenib, but not bevacizumab, reduced microvascular density and suppressed tumor growth relative to controls. Evolution of blood flow velocities correlated with microvascular density and with the evolution of tumor size. Ultrasound imaging thus provides a useful non-invasive tool for preclinical evaluation of new anti-angiogenic therapies for HCC.

The HBx oncoprotein of hepatitis B virus potentiates cell transformation by inducing c-Myc-dependent expression of the RNA polymerase I transcription factor UBF.

BackgroundThe HBx oncoprotein of hepatitis B virus has been implicated in the development and progression of hepatocellular carcinoma (HCC). HBx engages multiple signalling and growth-promoting pathways to induce cell proliferation and enhance ribosome biogenesis. Interestingly, the levels of Upstream Binding Factor (UBF) required for rDNA transcription and ribosome biogenesis are found elevated in the HCC patients. However, the molecular mechanism of UBF overexpression under the HBx microenvironment and consequent cell transformation remains elusive.MethodsThe UBF gene expression was investigated after co-expressing HBx in immortalized human hepatocytes (IHH) and human hepatoma Huh7 cells. Gene expression analysis involved estimation of mRNA level by real-time PCR, western blotting of protein, chromatin immune-precipitation assay, BrdU incorporation assay and soft agar colony formation assay. UBF expression was also investigated in an HBx transgenic mouse model of HCC to get a better mechanistic insight under more physiological conditions.ResultsEctopic expression of HBx in IHH as well as Huh7 cells led to a marked increase in UBF expression both at mRNA and protein levels. Elevated levels of UBF were also observed in the hepatic tumors of HBx transgenic mice. Our ChIP studies revealed a marked increase in the occupancy of c-Myc on the UBF gene promoter in the presence of HBx and increase in its transcription. Enhanced UBF expression under the HBx microenvironment led to a marked increase in cell proliferation and transformation of IHH cells.ConclusionsOur study provides some compelling evidences in support of HBx-mediated increase in UBF levels that abets oncogenic onslaught in hepatic cells by increasing rDNA transcription and ribosome biogenesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-015-0293-5) contains supplementary material, which is available to authorized users.

Phase 3 randomized, double-blind, controlled study of cabozantinib (XL184) versus placebo in subjects with hepatocellular carcinoma who have received prior sorafenib (CELESTIAL; NCT01908426).

TPS496 Background: Currently, there are no approved systemic therapies for patients with advanced hepatocellular carcinoma (HCC) who fail sorafenib. Cabozantinib is an oral receptor tyrosine kinase inhibitor (TKI) with activity against tyrosine kinases including MET, RET and VEGFRs. MET and VEGFR signaling have been implicated in tumor neo-angiogenesis and invasion. MET is overexpressed in HCC compared with non-tumor liver tissue, with higher MET expression linked to poor prognosis. Cabozantinib prolonged survival in a MET-driven transgenic mouse model of HCC, and has demonstrated clinical activity in multiple solid tumor types, including 41 subjects with advanced HCC treated in a phase 2 randomized discontinuation study. Methods: This phase 3, randomized, double-blind study evaluates the efficacy and safety of cabozantinib compared with placebo in subjects with advanced HCC previously treated with sorafenib and have progressed following 1-2 prior systemic treatments for HCC. Subjects must be ≥ 18 year old, have Child-Pugh Score of A and ECOG PS ≤ 1. Subjects are randomized 2:1 to receive either cabozantinib or placebo. Stratification factors are etiology of disease, geographic region and the presence of extrahepatic spread of disease and/or macrovascular invasion. The primary endpoint is overall survival. Secondary endpoints are progression-free survival and objective response rate by RECIST 1.1. Additional endpoints include safety, tolerability, circulating tumor cells, serum bone markers and plasma biomarkers, effects on bony disease assessed by bone scan and health-related quality of life (HRQoL) using the EuroQol Health questionnaire (EQ-5D-5L). Enrollment was initiated in September 2013. Target recruitment is 760 subjects. A total of 621 events planned with 2 interim analyses (at 311 and 466 events) would provide 90% power to detect a 31.6% increase in OS (HR=0.76). Clinical trial information: NCT01908426.

742TiP - Phase 3 Randomized, Double-Blind, Controlled Study of Cabozantinib (Xl184) Vs Placebo in Subjects with Hepatocellular Carcinoma Who Have Received Prior Sorafenib (Celestial) (Nct01908426)

ABSTRACT Background: Currently, there are no approved systemic therapies for patients with advanced hepatocellular carcinoma (HCC) who fail sorafenib. Cabozantinib is an oral receptor tyrosine kinase inhibitor (TKI) with activity against tyrosine kinases including MET, RET and VEGFRs. MET and VEGFR signaling have been implicated in tumor neo-angiogenesis and invasion. MET is overexpressed in HCC compared with non-tumor liver tissue, with higher MET expression linked to poor prognosis. Cabozantinib prolonged survival in a MET-driven transgenic mouse model of HCC, and has demonstrated clinical activity in multiple solid tumor types, including 41 subjects with advanced HCC treated in a phase 2 randomized discontinuation study. Trial design: This phase 3, randomized, double-blind study evaluates the efficacy and safety of cabozantinib compared with placebo in subjects with advanced HCC previously treated with sorafenib and have progressed following 1-2 prior systemic treatments for HCC. Subjects must be ≥ 18 year old, have Child-Pugh Score of A and ECOG PS ≤ 1. Subjects are randomized 2:1 to receive either cabozantinib or placebo. Stratification factors are etiology of disease, geographic region and the presence of extrahepatic spread of disease and/or macrovascular invasion. The primary endpoint is overall survival. Secondary endpoints are progression-free survival and objective response rate by RECIST 1.1. Additional endpoints include safety, tolerability, circulating tumor cells, serum bone markers and plasma biomarkers, effects on bony disease assessed by bone scan and health-related quality of life (HRQoL) using the EuroQol Health questionnaire (EQ-5D-5L). Enrollment was initiated in September 2013. Target recruitment is 760 subjects. A total of 621 events planned with 2 interim analyses (at 311 and 466 events) would provide 90% power to detect a 31.6% increase in OS (HR = 0.76). This abstract was accepted and previously presented at ASCO 2014ILCA 2014. Disclosure: G.K. Abou-Alfa: Research Grants: Exelixis Consultancy: Exelixis; A. Cheng, T. Meyer, A.B. El-Khoueiry, M. Ikeda and T. Okusaka: Consultancy: Exelixis; H.G. Chun: Research grant: Exelixis Consultancy: Exelixis E. Janczewska: Research grant: Exelixis; J. Ping: Employee: Exelixis Stock ownership: Exelixis; A.E. Borgman-Hagey: Employee: Exelixis Stock Ownership: Exelixis; R.K. Kelley: Research grant: Exelixis Consultancy: Exelixis. All other authors have declared no conflicts of interest.

DLK1-DIO3 Genomic Imprinted MicroRNA Cluster at 14q32.2 Defines a Stemlike Subtype of Hepatocellular Carcinoma Associated with Poor Survival

Hepatocellular carcinoma (HCC) is a heterogeneous and highly aggressive malignancy, for which there are no effective cures. Identification of a malignant stemlike subtype of HCC may offer patients with a dismal prognosis a potential targeted therapy using c-MET and Wnt pathway inhibitors. MicroRNAs (miRNAs) show promise as diagnostic and prognostic tools for cancer detection and stratification. Using a TRE-c-Met-driven transgenic HCC mouse model, we identified a cluster of 23 miRNAs that is encoded within the Dlk1-Gtl2 imprinted region on chromosome 12qF1 overexpressed in all of the isolated liver tumors. Interestingly, this region is conserved among mammalian species and maps to the human DLK1-DIO3 region on chromosome 14q32.2. We thus examined the expression of the DLK1-DIO3 miRNA cluster in a cohort of 97 hepatitis B virus-associated HCC patients and identified a subgroup (n = 18) of patients showing strong coordinate overexpression of miRNAs in this cluster but not in other cancer types (breast, lung, kidney, stomach, and colon) that were tested. Expression levels of imprinted gene transcripts from neighboring loci in this 14q32.2 region and from a subset of other imprinted sites were concomitantly elevated in human HCC. Interestingly, overexpression of the DLK1-DIO3 miRNA cluster was positively correlated with HCC stem cell markers (CD133, CD90, EpCAM, Nestin) and associated with a high level of serum α-fetoprotein, a conventional biomarker for liver cancer, and poor survival rate in HCC patients. In conclusion, our findings suggest that coordinate up-regulation of the DLK1-DIO3 miRNA cluster at 14q32.2 may define a novel molecular (stem cell-like) subtype of HCC associated with poor prognosis.