Unique phenotype of hepatocellular cancers with exon-3 mutations in beta-catenin gene

Correlation between CTNNB1 mutation status and tumour phenotype in hepatitis B virus-related hepatocellular carcinoma

AIMS

The frequency of CTNNB1 mutation, one of the most frequent genetic events in hepatocellular carcinoma (HCC), is lower in Asian countries and in hepatitis B virus (HBV)-related HCCs. In this study, we evaluated the prevalence and types of CTNNB1-mutation in HBV-related HCC and correlated the molecular status with the histomorphological and immunohistochemical features.

METHODS AND RESULTS

A total of 108 consecutive cases of treatment-naïve, surgically resected HBV-related HCCs were selected. Targeted sequencing for CTNNB1 exons 3, 7 and 8 was performed, and the results were correlated with the expression pattern of glutamine synthetase (GS), nuclear β-catenin expression status and the histomorphological characteristics of the tumour. CTNNB1 mutations were identified in 13% of HBV-related HCCs; of these cases, mutations were found in D32-S37 (7%), T41 (4%) and S45 (2%) of exon 3. None of the HCCs demonstrated alterations in exons 7 and 8. CTNNB1 mutation was strongly associated with diffuse strong GS expression (P < 0.001), nuclear β-catenin expression (P < 0.001) and the classic CTNNB1 morphology (P = 0.038). Diffuse strong GS expression was observed in 78.6% of the CTNNB1-mutated HCCs, and nuclear β-catenin expression was identified in 64.3% of these cases. The classic CTNNB1 morphology was observed in 57% of all CTNNB1-mutated HCCs. Furthermore, programmed death-ligand 1 (PD-L1) was less frequently expressed in HCCs with classic CTNNB1 morphology.

CONCLUSIONS

CTNNB1 mutation was observed in 13% of HBV-related HCCs in this Korean cohort, and was associated with diffuse strong GS expression, nuclear β-catenin expression and classic CTNNB1 morphology.

Involvement of β-catenin expression in hepatocellular carcinoma prognosis in a cohort of patients undergoing curative treatment

BACKGROUND

Hepatocellular carcinoma is a tumor of epithelial origin that arises from the action of different carcinogens on the hepatocytes and has a high worldwide incidence. The prognostic markers of this disease have not been completely established. Mutations in the gene encoding β-catenin are overexpressed in hepatocellular carcinoma. The objective of our study was to correlate the molecular expression of β-catenin in hepatocellular carcinoma with the already known prognostic markers.

METHODS

We conducted an observational and prospective cohort study on adult patients diagnosed with hepatocellular carcinoma from whom samples of nontumor and tumor liver parenchyma were taken intraoperatively to correlate the molecular expression of β-catenin in hepatocellular carcinoma with the known prognostic markers.

RESULTS

A total of 81 samples were collected, of which 48 met the inclusion criteria. The final sample was divided into patients with a diagnosis of hepatocellular carcinoma on a cirrhotic liver, corresponding to 31 patients (64.6%), and patients with a diagnosis of hepatocellular carcinoma on a noncirrhotic liver, corresponding to 17 patients (35.4%). We found that overexpression of β-catenin and the neutrophil/lymphocyte ratio are independently related to disease-free survival, and both overexpression and molecular repression of β-catenin are independently related.

CONCLUSION

Molecular overexpression of β-catenin in hepatocellular carcinoma compared with nontumor tissue is associated with worse disease-free survival, and its combination with a high neutrophil-lymphocyte ratio worsens this prognosis.

Structure and expression of FAPP2 protein in hepatocellular carcinoma: Its effect and molecular mechanism on HepG2 and MHCC97H in clinical treatment

Hepatocellular carcinoma (HCC) is a common and lethal malignancy of the liver. The aim of this study was to reveal the structural characteristics of FAPP2, evaluate its expression in HepG2 and MHCC97H cells, and explore its potential role and molecular mechanism in the clinical treatment of hepatocellular carcinoma. The role of FAPP2 in these two cell lines was evaluated using cell function tests, such as cell proliferation, migration, and invasion tests. The interaction between FAPP2 and other related signaling pathways was further explored by bioinformatics analysis. The structural analysis of FAPP2 shows that it has specific domains and functional sites, which are closely related to its biological function in the cell. FAPP2 expression in HepG2 cells was significantly higher than that in MHCC97H cells. Functional experiments showed that overexpression of FAPP2 promoted the proliferation and migration of HepG2 cells, but no such effect was seen in MHCC97H cells. Bioinformatics analysis revealed a potential association between FAPP2 and the PI3K/Akt signaling pathway.

Novel Location-Grading-Node-Metastasis Staging System in Patients With Head and Neck Soft Tissue Sarcoma

ImportanceUnlike other head and neck cancers, head and neck soft tissue sarcoma (HN-STS) is staged similarly to sarcomas in the trunk and extremities. The current American Joint Committee on Cancer (AJCC) staging system has limitations that hinder accurate prognosis prediction for HN-STS.ObjectiveWe aimed to develop a novel location-grading-node-metastasis (LGNM) staging system based on the primary tumor location to more accurately stratify prognosis for HN-STS.DesignA retrospective case series from 1990 to 2021.Setting/ParticipantsThis study included 471 patients diagnosed with HN-STS at Sun Yat-sen University Cancer Center between 1990 and 2021.Main outcome measuresIn the primary analysis, we obtained the overall survival (OS) rate. Secondary measures included area under the receiver operating characteristic curve, Harrell's C, Somers' D, Gönen and Heller's K, O'Quigley's ρ2k, Royston's R2, the Bayesian information criterion for concordance, and variation in patient outcomes.ResultsThe eighth edition of AJCC T classification for tumor size inadequately conveys prognosis information. In contrast, the primary tumor location and local invasion are prognostic factors for HN-STS and categorized into 4 stages: L1 (low risk: scalp, face, supraclavicular, ear), L2 (intermediate risk: neck, paravertebral, pharynx, tonsil, eye, orbit), L3 (high risk: cavity, lip, palate, buccal mucosa, salivary gland, maxilla, mandible), and L4 (any location with local invasion). The new LGNM staging system effectively distributed patients into stages I to IV, with statistically-significant survival differences among these stages. Five-year OS rates were 96.9% for stage I, 78.4% for stage II, 37.1% for stage III, and 7.1% for stage IV (P < .001). Additionally, the LGNM staging system demonstrated superior predictive ability and concordance compared with the seventh and eighth editions of AJCC staging systems.Conclusions/RelevanceThe LGNM staging system shows better homogeneity and discriminatory power than the AJCC system, improving risk stratification and prognosis prediction in HN-STS.

Specific features of ß-catenin-mutated hepatocellular carcinomas

CTNNB1, encoding the ß-catenin protein, is a key oncogene contributing to liver carcinogenesis. Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer in adult, representing the third leading cause of cancer-related death. Aberrant activation of the Wnt/ß-catenin pathway, mainly due to mutations of the CTNNB1 gene, is observed in a significant subset of HCC. In this review, we first resume the major recent advances in HCC classification with a focus on CTNNB1-mutated HCC subclass. We present the regulatory mechanisms involved in β-catenin stabilisation, transcriptional activity and binding to partner proteins. We then describe specific phenotypic characteristics of CTNNB1-mutated HCC thanks to their unique gene expression patterns. CTNNB1-mutated HCC constitute a full-fledged subclass of HCC with distinct pathological features such as well-differentiated cells with low proliferation rate, association to cholestasis, metabolic alterations, immune exclusion and invasion. Finally, we discuss therapeutic approaches to target ß-catenin-mutated liver tumours and innovative perspectives for future drug developments.

Wnt/β-Catenin signaling pathway in hepatocellular carcinoma: pathogenic role and therapeutic target

Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor and one of the leading causes of cancer-related deaths worldwide. The Wnt/β-Catenin signaling pathway is a highly conserved pathway involved in several biological processes, including the improper regulation that leads to the tumorigenesis and progression of cancer. New studies have found that abnormal activation of the Wnt/β-Catenin signaling pathway is a major cause of HCC tumorigenesis, progression, and resistance to therapy. New perspectives and approaches to treating HCC will arise from understanding this pathway. This article offers a thorough analysis of the Wnt/β-Catenin signaling pathway's function and its therapeutic implications in HCC.

The assessment of circulating tumor DNA associated with Wnt/β-catenin signaling pathway as a diagnostic tool for liver cancer: a systematic review and meta-analysis

BACKGROUND

Circulating tumor DNA (ctDNA) in peripheral blood has become a promising noninvasive biomarker. However, the diagnostic potential of Wnt/β-catenin signaling pathway-related ctDNA for liver cancer is controversial. Here, we aimed to access the diagnostic potential and clinicopathological features of Wnt/β-catenin signaling pathway-related ctDNA in liver cancer and provide data support for its clinical diagnosis and treatment.

METHODS

A comprehensive literature search was conducted to identify the relevant studies. The methodological quality of the included studies was evaluated using the QUADAS-2 tool. The bivariate linear mixed models were used.

RESULTS

The AUC (area under the curve), pooled sensitivity and specificity were 0.77, 0.42 and 0.98, respectively. The findings suggested that control type, sample source, research methods and thresholds were the potential sources of heterogeneity (p < 0.05). Additionally, this study also found that there were significant correlations between the hypermethylation of Wnt/β-catenin signaling pathway-related ctDNA and tumor size, TNM stage, distant metastasis, and HBV infection(p < 0.05).

CONCLUSION

This study confirmed that Wnt/β-catenin signaling pathway-related ctDNA had the better diagnostic potential for liver cancer and might be an effective complementary tool for serum AFP assays in the early diagnosis of liver cancer.

PROSPERO

(No. CRD42023404984).[Figure: see text].

Wnt/β-catenin signaling pathway in the tumor progression of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an uncommon, aggressive endocrine malignancy with a high rate of recurrence, a poor prognosis, and a propensity for metastasis. Currently, only mitotane has received certification from both the US Food and Drug Administration (FDA) and the European Medicines Agency for the therapy of advanced ACC. However, treatment in the advanced periods of the disorders is ineffective and has serious adverse consequences. Completely surgical excision is the only cure but has failed to effectively improve the survival of advanced patients. The aberrantly activated Wnt/β-catenin pathway is one of the catalysts for adrenocortical carcinogenesis. Research has concentrated on identifying methods that can prevent the stimulation of the Wnt/β-catenin pathway and are safe and advantageous for patients in view of the absence of effective treatments and the frequent alteration of the Wnt/β-catenin pathway in ACC. Comprehending the complex connection between the development of ACC and Wnt/β-catenin signaling is essential for accurate pharmacological targets. In this review, we summarize the potential targets between adrenocortical carcinoma and the Wnt/β-catenin signaling pathway. We analyze the relevant targets of drugs or inhibitors that act on the Wnt pathway. Finally, we provide new insights into how drugs or inhibitors may improve the treatment of ACC.

Prognostic significance of CTNNB1 mutation in hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUNDS

Hepatocellular Carcinoma (HCC) is one of the most common malignant cancers in humans and has a high fatality rate. In recent years, researchers have verified that the Wnt/β-catenin signaling pathway affects the clinicopathological features and prognosis of patients with HCC. Although many studies have investigated the relationship between Wnt/β-catenin signaling pathway and HCC, the prognostic value of β-catenin in HCC remains inconclusive. CTNNB1 (Catenin Beta-1) is an important factor in the Wnt/β-catenin signaling pathway. However, no consensus has been reached on the clinical and prognostic significance of CTNNB1 mutations in HCCs.

METHODS

Eligible studies and relevant data were obtained from PubMed, Web of Science, Elsevier, Cochrane Library, Ovid, and Embase databases. The correlation between CTNNB1 mutations and clinical/prognosis of patients were evaluated. A fixed- or random-effects model was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Seventeen studies matched the selection criteria, and 1828 patients were included. This meta-analysis demonstrated that patients with HCC with CTNNB1 mutations had favorable clinicopathological features and survival. The combined ORs of 1-, 3- and 5-year overall survival were0.52 (n = 6 studies, 95% CI: 0.34-0.81, Z = 2.89, P =0.004, 0.28 (n =6 studies, 95% CI: 0.18-0.42, Z = 6.03, P<0.00001), -0.22 (n = 6 studies, 95% CI: 0.37-0.06, Z = 2.78, P = 0.005), respectively. Additionally, CTNNB1 mutation might be significantly associated with differentiation (OR = 0.54, 95% CI:0.36-0.81, Z = 2.98, P = 0.003), TMN stages (Tumor, Node, Metastasis staging classification) (OR = -0.25, 95% CI:-0.33--0.18, Z = 6.60, P<0.00001), liver cirrhosis (OR = 0.21, 95% CI:0.11-0.39, Z = 4.94, P< = 0.00001), and HBV (Hepatitis B Virus) infection (OR = 0.44, 95% CI:0.31-0.64, Z = 4.37, P<0.0001), but not with tumor size, metastasis, vascular invasion, and HCV infection.

CONCLUSIONS

CTNNB1 mutation can serve as an indicator of favorable prognosis as well as a novel target for treatment in HCC.

Organoid models of fibrolamellar carcinoma mutations reveal hepatocyte transdifferentiation through cooperative BAP1 and PRKAR2A loss

Fibrolamellar carcinoma (FLC) is a lethal primary liver cancer, affecting young patients in absence of chronic liver disease. Molecular understanding of FLC tumorigenesis is limited, partly due to the scarcity of experimental models. Here, we CRISPR-engineer human hepatocyte organoids to recreate different FLC backgrounds, including the predominant genetic alteration, the DNAJB1-PRKACA fusion, as well as a recently reported background of FLC-like tumors, encompassing inactivating mutations of BAP1 and PRKAR2A. Phenotypic characterizations and comparisons with primary FLC tumor samples revealed mutant organoid-tumor similarities. All FLC mutations caused hepatocyte dedifferentiation, yet only combined loss of BAP1 and PRKAR2A resulted in hepatocyte transdifferentiation into liver ductal/progenitor-like cells that could exclusively grow in a ductal cell environment. BAP1-mutant hepatocytes represent primed cells attempting to proliferate in this cAMP-stimulating environment, but require concomitant PRKAR2A loss to overcome cell cycle arrest. In all analyses, DNAJB1-PRKACA^fus organoids presented with milder phenotypes, suggesting differences between FLC genetic backgrounds, or for example the need for additional mutations, interactions with niche cells, or a different cell-of-origin. These engineered human organoid models facilitate the study of FLC.

Cellular and Molecular Biology of Cancer Stem Cells of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death globally. The cancer stem cells (CSCs) of HCC are responsible for tumor growth, invasion, metastasis, recurrence, chemoresistance, target therapy resistance and radioresistance. The reported main surface markers used to identify liver CSCs include epithelial cell adhesion/activating molecule (EpCAM), cluster differentiation 90 (CD90), CD44 and CD133. The main molecular signaling pathways include the Wnt/β-catenin, transforming growth factors-β (TGF-β), sonic hedgehog (SHH), PI3K/Akt/mTOR and Notch. Patients with EpCAM-positive alpha-fetoprotein (AFP)-positive HCC are usually young but have advanced tumor-node-metastasis (TNM) stages. CD90-positive HCCs are usually poorly differentiated with worse prognosis. Those with CD44-positive HCC cells develop early metastases. Those with CD133 expression have a higher recurrence rate and a shorter overall survival. The Wnt/β-catenin signaling pathway triggers angiogenesis, tumor infiltration and metastasis through the enhancement of angiogenic factors. All CD133+ liver CSCs, CD133+/EpCAM+ liver CSCs and CD44+ liver CSCs contribute to sorafenib resistance. SHH signaling could protect HCC cells against ionizing radiation in an autocrine manner. Reducing the CSC population of HCC is crucial for the improvement of the therapy of advanced HCC. However, targeting CSCs of HCC is still challenging.

CTNNB1 polymorphism (rs121913407) in circulating tumor DNA (ctDNA) in Egyptian hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) represents the sixth most common cancer worldwide and the fourth in Egypt. Persistent inflammation and specific somatic mutations in driving genes play a major role in the development of HCC. One of these somatic mutations is CTNNB1 mutations with subsequent activation of β-catenin in HCC, associated with a risk of malignant transformation. In this study, we investigate the clinical utility of peripheral blood circulating tumor DNA (ctDNA) CTNNB1 (rs121913407) in HCC patients compared to pathological chronic hepatitis C virus (HCV) patients and healthy controls.

Methods

Our study is a case-control study at the Ain Shams Centre for Organ Transplantation, Ain Shams University Hospitals, enrolling twenty-eight adult HCC patients (twelve early HCC patients and sixteen advanced HCC patients), ten patients with chronic hepatitis C as a disease control group, and ten healthy controls. We collected plasma and stored at −80 °C. We detected mutations in the gene locus CTNNB1 rs121913407 by real-time PCR.

Results

All of our studied cases (early and advanced HCC) in addition to HCV and healthy control groups were CTNNB1 wild (TT) genotype. There was statistical significant difference between early and late cases of HCC as regards AFP and AST.

Conclusions

None of our recruited subjects showed CTNNB1 rs121913407 gene mutation. Further studies on larger number of patients are needed to clarify and confirm the clinical utility of CTNNB1 single-nucleotide polymorphism in the pathogenesis of HCC related to HCV in Egyptian population.

Wnt/β-catenin targeting in liver carcinoma through nanotechnology-based drug repurposing: A review

Liver cancer is the fifth most widespread in the world, with a high fatality rate and poor prognosis.However,surgicalresction,thermal/radiofrequencyablation,chemo/radioembolization and pathway targeting to the cancer cells are all possible options for treating Liver Carcinoma. Unfortunately, once the tumour has developed and spread, diagnosis often occurs too late. The targeted therapy has demonstrated notable, albeit modest, efficacy in some patients with advanced HCC. This demonstrates the necessity of creating additional focused treatments and, in pursuit of this end, the need to find ever-more pathways as prospective targets. Despite the critical need, there are currently no Wnt signalling directed therapy on the research field, only a few methods have progressed beyond the early stage of clinical studies. In the present study, we report that repurposing of drug previously licensed for other diseases is one possible strategy inhibit malignant cell proliferation and renewal by removing individuals protein expression in the Wnt/β-catenin pathway. Particularly β-catenin complex is present in Liver cancer, where tumour necrosis factor is indispensable for the complex formation and β-catenin interactions are disrupted upon drug in nano-carrier through nanotechnology. This study findings not only highlight that repurposing drug could improve liver cancer treatment outcomes but also focused to character traits and functions of the Wnt signalling cascade's molecular targets and how they could be used to get anti-tumour results method to targeting Wnt/β-catenin in liver carcinoma.

The Role of Chronic Liver Diseases in the Emergence and Recurrence of Hepatocellular Carcinoma: An Omics Perspective

Hepatocellular carcinoma (HCC) typically develops from a background of cirrhosis resulting from chronic inflammation. This inflammation is frequently associated with chronic liver diseases (CLD). The advent of next generation sequencing has enabled extensive analyses of molecular aberrations in HCC. However, less attention has been directed to the chronically inflamed background of the liver, prior to HCC emergence and during recurrence following surgery. Hepatocytes within chronically inflamed liver tissues present highly activated inflammatory signaling pathways and accumulation of a complex mutational landscape. In this altered environment, cells may transform in a stepwise manner toward tumorigenesis. Similarly, the chronically inflamed environment which persists after resection may impact the timing of HCC recurrence. Advances in research are allowing an extensive epigenomic, transcriptomic and proteomic characterization of CLD which define the emergence of HCC or its recurrence. The amount of data generated will enable the understanding of oncogenic mechanisms in HCC from the CLD perspective and provide the possibility to identify robust biomarkers or novel therapeutic targets for the treatment of primary and recurrent HCC. Importantly, biomarkers defined by the analysis of CLD tissue may permit the early detection or prevention of HCC emergence and recurrence. In this review, we compile the current omics based evidence of the contribution of CLD tissues to the emergence and recurrence of HCC.

A framework for fibrolamellar carcinoma research and clinical trials

Fibrolamellar carcinoma (FLC), a rare, lethal hepatic cancer, occurs primarily in adolescents and young adults. Unlike hepatocellular carcinoma, FLC has no known association with viral, metabolic or chemical agents that cause cirrhosis. Currently, surgical resection is the only treatment demonstrated to achieve cure, and no standard of care exists for systemic therapy. Progress in FLC research illuminates a transition from an obscure cancer to one for which an interactive community seems poised to uncover fundamental mechanisms and initiate translation towards novel therapies. In this Roadmap, we review advances since the seminal discovery in 2014 that nearly all FLC tumours express a signature oncogene (DNAJB1-PRKACA) encoding a fusion protein (DNAJ-PKAc) in which the J-domain of a heat shock protein 40 (HSP40) co-chaperone replaces an amino-terminal segment of the catalytic subunit of the cyclic AMP-dependent protein kinase (PKA). Important gains include increased understanding of oncogenic pathways driven by DNAJ-PKAc; identification of potential therapeutic targets; development of research models; elucidation of immune mechanisms with potential for the development of immunotherapies; and completion of the first multicentre clinical trials of targeted therapy for FLC. In each of these key areas we propose a Roadmap for future progress.

β-Catenin signaling in hepatocellular carcinoma

Deregulated Wnt/β-catenin signaling is one of the main genetic alterations in human hepatocellular carcinoma (HCC). Comprehensive genomic analyses have revealed that gain-of-function mutation of CTNNB1, which encodes β-catenin, and loss-of-function mutation of AXIN1 occur in approximately 35% of human HCC samples. Human HCCs with activation of the Wnt/β-catenin pathway demonstrate unique gene expression patterns and pathological features. Activated Wnt/β-catenin synergizes with multiple signaling cascades to drive HCC formation, and it functions through its downstream effectors. Therefore, strategies targeting Wnt/β-catenin have been pursued as possible therapeutics against HCC. Here, we review the genetic alterations and oncogenic roles of aberrant Wnt/β-catenin signaling during hepatocarcinogenesis. In addition, we discuss the implication of this pathway in HCC diagnosis, classification, and personalized treatment.

Current Perspectives on the Immunosuppressive Niche and Role of Fibrosis in Hepatocellular Carcinoma and the Development of Antitumor Immunity

Immune checkpoint inhibitors have become the mainstay of treatment for hepatocellular carcinoma (HCC). However, they are ineffective in some cases. Previous studies have reported that genetic alterations in oncogenic pathways such as Wnt/β-catenin are the important triggers in HCC for primary refractoriness. T-cell exhaustion has been reported in various tumors and is likely to play a prominent role in the emergence of HCC due to chronic inflammation and cirrhosis-associated immune dysfunction. Immunosuppressive cells including regulatory T-cells and tumor-associated macrophages infiltrating the tumor are associated with hyperprogressive disease in the early stages of immune checkpoint inhibitor treatment. In addition, stellate cells and tumor-associated fibroblasts create an abundant desmoplastic environment by producing extracellular matrix. This strongly contributes to epithelial to mesenchymal transition via signaling activities including transforming growth factor beta, Wnt/β-catenin, and Hippo pathway. The abundant desmoplastic environment has been demonstrated in pancreatic ductal adenocarcinoma and cholangiocarcinoma to suppress cytotoxic T-cell infiltration, PD-L1 expression, and neoantigen expression, resulting in a highly immunosuppressive niche. It is possible that a similar immunosuppressive environment is created in HCC with advanced fibrosis in the background liver. Although sufficient understanding is required for the establishment of immune therapies of HCC, further investigations are still required in this field.

Associations of Serum Tumor Biomarkers with Integrated Genomic and Clinical Characteristics of Hepatocellular Carcinoma

INTRODUCTION

Serum α-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP (AFP-L3), and des-γ-carboxy-pro-thrombin (DCP) are useful biomarkers of hepatocellular carcinoma (HCC). However, associations among molecular characteristics and serum biomarkers are unclear. We analyzed RNA expression and DNA variant data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) to examine their associations with serum biomarker levels and clinical data.

METHODS

From 371 TCGA-LIHC patients, we selected 91 seen at 3 institutions in Korea and the USA and measured AFP, AFP-L3, and DCP from preoperatively obtained serum. We conducted an integrative clinical and molecular analysis, focusing on biomarkers, and validated the findings with the remaining 280 patients in the TCGA-LIHC cohort.

RESULTS

Patients were categorized into 4 subgroups: elevated AFP or AFP-L3 alone (↑AFP&L3), elevated DCP alone (↑DCP), elevation of all 3 biomarkers (elevated levels of all 3 biomarkers [↑All]), and reference range values for all biomarkers (RR). CTNNB1 variants were frequently observed in ↑DCP patients (53.8%) and RR patients (38.5%), but ↑DCP patients with a CTNNB1 variant had worse survival than RR patients. TP53 sequence variants were associated with ↑AFP (30.8%) and ↑DCP (30.8%). The Wnt-β-catenin signaling pathway was activated in the ↑AFP&L3, whereas liver-related Wnt signaling was activated in the RR. TGF-β and VEGF signaling were activated in ↑AFP&L3, whereas dysregulated bile acid and fatty acid metabolism were dominant in ↑DCP. We validated these findings by showing similar results between the test cohort and the remainder of the TCGA-LIHC cohort.

CONCLUSIONS

Serum AFP, AFP-L3, and DCP levels can help predict variants in the genetic profile of HCC, especially for TP53 and CTNNB1. These findings may facilitate development of an evidence-based approach to treatment.

Circulating Tumor Cells in Desmoid Tumors: New Perspectives

Introduction

Desmoid tumor (DT) is a rare neoplasm with high local recurrence rates, composed of fibroblastic cells that are characterized by the expression of key molecules, including the intermediate filament vimentin, cyclooxygenase-2 (COX-2), and nuclear β-catenin, and lack of epithelial markers. Circulating tumor cells (CTCs) isolated from the peripheral blood of patients with sarcomas and other neoplasms can be used as early biomarkers of tumor invasion and dissemination. Moreover, CTCs can also re-colonize their tumors of origin through a process of "tumor self-seeding."

Objectives

We aimed to identify CTCs in the peripheral blood of patients with DT and evaluate their expression of β-catenin, transforming growth factor receptor I (TGF-βRI), COX-2, and vimentin proteins.

Material and Methods

We conducted a prospective study of patients with initial diagnosis or relapsed DT with measurable disease. Blood samples from each patient were processed and filtered by ISET^® (Rarecells, France) for CTC isolation and quantification. The CTC expression of β-catenin, COX-2, TGF-βRI, and vimentin was analyzed by immunocytochemistry (ICC).

Results

A total of 18 patients were included, and all had detectable CTCs. We found a concordance of β-catenin expression in both CTCs and primary tumors in 42.8% (6/14) of cases by using ICC and immunohistochemistry, respectively.

Conclusions

Our study identified a high prevalence of CTCs in DT patients. Concordance of β-catenin expression between primary tumor and CTCs brings new perspectives to assess the dynamics of CTCs in the blood compartment, opening new avenues for studying the biology and behavior of DT. In addition, these results open the possibility of using CTCs to predict DT dynamics at the time of disease progression and treatment. Further studies with larger sample sizes are needed to validate our findings.

Glucose and Amino Acid Metabolic Dependencies Linked to Stemness and Metastasis in Different Aggressive Cancer Types

Malignant cells are commonly characterised by being capable of invading tissue, growing self-sufficiently and uncontrollably, being insensitive to apoptosis induction and controlling their environment, for example inducing angiogenesis. Amongst them, a subpopulation of cancer cells, called cancer stem cells (CSCs) shows sustained replicative potential, tumor-initiating properties and chemoresistance. These characteristics make CSCs responsible for therapy resistance, tumor relapse and growth in distant organs, causing metastatic dissemination. For these reasons, eliminating CSCs is necessary in order to achieve long-term survival of cancer patients. New insights in cancer metabolism have revealed that cellular metabolism in tumors is highly heterogeneous and that CSCs show specific metabolic traits supporting their unique functionality. Indeed, CSCs adapt differently to the deprivation of specific nutrients that represent potentially targetable vulnerabilities. This review focuses on three of the most aggressive tumor types: pancreatic ductal adenocarcinoma (PDAC), hepatocellular carcinoma (HCC) and glioblastoma (GBM). The aim is to prove whether CSCs from different tumour types share common metabolic requirements and responses to nutrient starvation, by outlining the diverse roles of glucose and amino acids within tumour cells and in the tumour microenvironment, as well as the consequences of their deprivation. Beyond their role in biosynthesis, they serve as energy sources and help maintain redox balance. In addition, glucose and amino acid derivatives contribute to immune responses linked to tumourigenesis and metastasis. Furthermore, potential metabolic liabilities are identified and discussed as targets for therapeutic intervention.

Cooperation between liver-specific mutations of pten and tp53 genetically induces hepatocarcinogenesis in zebrafish

BACKGROUND

Liver cancer, mainly hepatocellular carcinoma, is one of the deadliest cancers worldwide and has a poor prognosis due to insufficient understanding of hepatocarcinogenesis. Previous studies have revealed that the mutations in PTEN and TP53 are the two most common genetic events in hepatocarcinogenesis. Here, we illustrated the crosstalk between aberrant Pten and Tp53 pathways during hepatocarcinogenesis in zebrafish.

METHODS

We used the CRISPR/Cas9 system to establish several transgenic zebrafish lines with single or double tissue-specific mutations of pten and tp53 to genetically induce liver tumorigenesis. Next, the morphological and histological determination were performed to investigate the roles of Pten and Tp53 signalling pathways in hepatocarcinogenesis in zebrafish.

RESULTS

We demonstrated that Pten loss alone induces hepatocarcinogenesis with only low efficiency, whereas single mutation of tp53 failed to induce tumour formation in liver tissue in zebrafish. Moreover, zebrafish with double mutations of pten and tp53 exhibits a much higher tumour incidence, higher-grade histology, and a shorter survival time than single-mutant zebrafish, indicating that these two signalling pathways play important roles in dynamic biological events critical for the initiation and progression of hepatocarcinogenesis in zebrafish. Further histological and pathological analyses showed significant similarity between the tumours generated from liver tissues of zebrafish and humans. Furthermore, the treatment with MK-2206, a specific Akt inhibitor, effectively suppressed hepatocarcinogenesis in zebrafish.

CONCLUSION

Our findings will offer a preclinical animal model for genetically investigating hepatocarcinogenesis and provide a useful platform for high-throughput anticancer drug screening.

New Scope of Targeted Therapies in Lung Carcinoma

Lung cancer (LC) is the leading cause of cancer deaths worldwide. Recent research has also shown LC as a genomic disease, causing somatic mutations in patients. Tests related to mutational analysis and genome profiles have lately expanded significantly in the genetics/genomics field of LC. This review summarizes the current knowledge about different signalling pathways of LC based on the clinical impact of molecular targets. It describes the main molecular pathways and changes involved in the development, progression, and cellular breakdown of LC and the molecular changes. This review focuses on approved and targeted experimental therapies such as immunotherapy and clinical trials that examine the different targeted approaches to treating LC. We aimto clarify the differences in the extent of various genetic mutations in several areas for LC patients. Targeted molecular therapies for LC can be continued with advanced racial differences in genetic changes, which have a significant impact on the choice of drug treatment and our understanding of the profile of drug susceptibility/resistance. The most relevant genes described in this review are EGFR, KRAS, MET, BRAF, PIK3CA, STK11, ERBB3, PTEN, and RB1. Combined research efforts in this field are required to understand the genetic difference in LC outcomes in the future.

UBE3C promotes proliferation and inhibits apoptosis by activating the β-catenin signaling via degradation of AXIN1 in gastric cancer

Gastric cancer (GC) remains one of the most frequent cancers worldwide. Previous studies have shown that E3 ubiquitin ligase E3C (UBE3C) promotes the progression of multiple types of cancer. However, little is known about the expression and molecular mechanism of UBE3C in GC. In this study, UBE3C is upregulated in clinical GC samples and RNA-seq data from The Cancer Genome Atlas, and the UBE3C upregulation is correlated with poor clinical outcomes in patients with GC. In vitro, knockdown of UBE3C suppresses proliferation and enhances apoptosis in GC cells by inhibiting β-catenin signaling pathway. In contrast, in vitro overexpression of UBE3C promotes GC cell proliferation and inhibits apoptosis through the upregulation of β-catenin signaling by promoting ubiquitination of AXIN1. In vivo, knockdown of UBE3C inhibits tumor growth in a nude mouse model. Concurrently, the UBE3C knockdown resulted in an increase of AXIN1 and a reduction of β-catenin in the nucleus and cytoplasm in the xenograft tumor tissues. Our results demonstrate that UBE3C promotes GC progression through activating the β-catenin signaling via degradation of AXIN1. Our data suggest that UBE3C exerts oncogenic effects in GC and thus provides a promising prognostic biomarker and a potential therapeutic target for GC therapy.

LncAY controls BMI1 expression and activates BMI1/Wnt/β-catenin signaling axis in hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. Long non-coding RNAs as master gene regulators play important roles in tumorigenesis and progression. However, the significance of lncRNAs and their regulatory mechanisms in HCC are largely unknown. Our study was to define the role of lncAY (long noncoding RNA AY927503) in HCC.

METHODS

Methylated RNA immunoprecipitation qPCR combined with bioinformatics were used to identify the m6A modification of lncAY. qRT-PCR, western blotting and immunofluorescence were used to identify the expression of the lncAY/YTHDF2/BMI1/Wnt axis in HCC tissues and cell lines. Gain- and loss-of functions of lncAY and BMI1 were implemented to confirm their roles in the behaviors of HCC cells.

RESULTS

Our findings suggested that m6A-modified lncAY expression relied on m6A "reader" protein YTHDF2. LncAY upregulated BMI1 expression in HCC cells and a notably positive relevance is evident between lncAY and BMI1 expression in TCGA HCC datasets. BMI1 was upregulated in HCC tissues and patients with higher BMI1 expression had a poor clinical prognosis. Besides, GSEA analysis showed remarkable enrichment of high BMI1 expression in gene sets associated with Wnt/β-catenin signaling. Rescue results revealed that BMI1 reversed the suppressive effects of lncAY depletion in HCC cells.

CONCLUSIONS

Our work suggested that lncAY might elevate BMI1 expression and further activate the Wnt/β-catenin signaling. BMI1 reverses the suppressive effects of lncAY depletion in HCC cells. Collectively, our work uncovers a novel undefined regulatory signaling pathway, namely lncAY/BMI1/Wnt/β-catenin axis, involved in liver cancer progression.

Wnt/β-catenin signaling pathway in uterine leiomyoma: role in tumor biology and targeting opportunities

Uterine leiomyoma is the most common tumor of the female reproductive system and originates from a single transformed myometrial smooth muscle cell. Despite the immense medical, psychosocial, and financial impact, the exact underlying mechanisms of leiomyoma pathobiology are poorly understood. Alterations of signaling pathways are thought to be instrumental in leiomyoma biology. Wnt/β-catenin pathway appears to be involved in several aspects of the genesis of leiomyomas. For example, Wnt5b is overexpressed in leiomyoma, and the Wnt/β-catenin pathway appears to mediate the role of MED12 mutations, the most common mutations in leiomyoma, in tumorigenesis. Moreover, Wnt/β-catenin pathway plays a paracrine role where estrogen/progesterone treatment of mature myometrial or leiomyoma cells leads to increased expression of Wnt11 and Wnt16, which induces proliferation of leiomyoma stem cells and tumor growth. Constitutive activation of β-catenin leads to myometrial hyperplasia and leiomyoma-like lesions in animal models. Wnt/β-catenin signaling is also closely involved in mechanotransduction and extracellular matrix regulation and relevant alterations in leiomyoma, and crosstalk is noted between Wnt/β-catenin signaling and other pathways known to regulate leiomyoma development and growth such as estrogen, progesterone, TGFβ, PI3K/Akt/mTOR, Ras/Raf/MEK/ERK, IGF, Hippo, and Notch signaling. Finally, evidence suggests that inhibition of the canonical Wnt pathway using β-catenin inhibitors inhibits leiomyoma cell proliferation. Understanding the molecular mechanisms of leiomyoma development is essential for effective treatment. The specific Wnt/β-catenin pathway molecules discussed in this review constitute compelling candidates for therapeutic targeting.

β-Catenin Activation in Hepatocellular Cancer: Implications in Biology and Therapy

Simple Summary

Liver cancer is a dreadful tumor which has gradually increased in incidence all around the world. One major driver of liver cancer is the Wnt–β-catenin pathway which is active in a subset of these tumors. While this pathway is normally important in liver development, regeneration and homeostasis, it’s excessive activation due to mutations, is detrimental and leads to tumor cell growth, making it an important therapeutic target. There are also some unique characteristics of this pathway activation in liver cancer. It makes the tumor addicted to specific amino acids and in turn to mTOR signaling, which can be treated by certain existing therapies. In addition, activation of the Wnt–β-catenin in liver cancer appears to alter the immune cell landscape making it less likely to respond to the new immuno-oncology treatments. Thus, Wnt–β-catenin active tumors may need to be treated differently than non-Wnt–β-catenin active tumors.

Abstract

Hepatocellular cancer (HCC), the most common primary liver tumor, has been gradually growing in incidence globally. The whole-genome and whole-exome sequencing of HCC has led to an improved understanding of the molecular drivers of this tumor type. Activation of the Wnt signaling pathway, mostly due to stabilizing missense mutations in its downstream effector β-catenin (encoded by CTNNB1) or loss-of-function mutations in AXIN1 (the gene which encodes for Axin-1, an essential protein for β-catenin degradation), are seen in a major subset of HCC. Because of the important role of β-catenin in liver pathobiology, its role in HCC has been extensively investigated. In fact, CTNNB1 mutations have been shown to have a trunk role. β-Catenin has been shown to play an important role in regulating tumor cell proliferation and survival and in tumor angiogenesis, due to a host of target genes regulated by the β-catenin transactivation of its transcriptional factor TCF. Proof-of-concept preclinical studies have shown β-catenin to be a highly relevant therapeutic target in CTNNB1-mutated HCCs. More recently, studies have revealed a unique role of β-catenin activation in regulating both tumor metabolism as well as the tumor immune microenvironment. Both these roles have notable implications for the development of novel therapies for HCC. Thus, β-catenin has a pertinent role in driving HCC development and maintenance of this tumor-type, and could be a highly relevant therapeutic target in a subset of HCC cases.

Integrative Pan-Cancer Analysis Reveals Decreased Melatonergic Gene Expression in Carcinogenesis and RORA as a Prognostic Marker for Hepatocellular Carcinoma

Background

Melatonin has been shown to play a protective role in the development and progression of cancer. However, the relationship between alterations in the melatonergic microenvironment and cancer development has remained unclear.

Methods

We performed a comprehensive investigation on 12 melatonergic genes and their relevance to cancer occurrence, progression and survival by integrating multi-omics data from microarray analysis and RNA sequencing across 11 cancer types. Specifically, the 12 melatonergic genes that we investigated, which reflect the melatonergic microenvironment, included three membrane receptor genes, three nuclear receptor genes, two intracellular receptor genes, one synthetic gene, and three metabolic genes.

Results

Widely coherent underexpression of nuclear receptor genes, intracellular receptor genes, and metabolic genes was observed in cancerous samples from multiple cancer types compared to that in normal samples. Furthermore, genomic and/or epigenetic alterations partially contributed to these abnormal expression patterns in cancerous samples. Moreover, the majority of melatonergic genes had significant prognostic effects in predicting overall survival. Nevertheless, few corresponding alterations in expression were observed during cancer progression, and alterations in expression patterns varied greatly across cancer types. However, the association of melatonergic genes with one specific cancer type, hepatocellular carcinoma, identified RORA as a tumor suppressor and a prognostic marker for patients with hepatocellular carcinoma.

Conclusions

Overall, our study revealed decreased melatonergic gene expression in various cancers, which may help to better elucidate the relationship between melatonin and cancer development. Taken together, our findings highlight the potential prognostic significance of melatonergic genes in various cancers.

Targeting EphA2 suppresses hepatocellular carcinoma initiation and progression by dual inhibition of JAK1/STAT3 and AKT signaling

Hepatocellular carcinoma (HCC) remains one of the deadliest malignancies worldwide. One major obstacle to treatment is a lack of effective molecular-targeted therapies. In this study, we find that EphA2 expression and signaling are enriched in human HCC and associated with poor prognosis. Loss of EphA2 suppresses the initiation and growth of HCC both in vitro and in vivo. Furthermore, CRISPR/CAS9-mediated EphA2 inhibition significantly delays tumor development in a genetically engineered murine model of HCC. Mechanistically, we discover that targeting EphA2 suppresses both AKT and JAK1/STAT3 signaling, two separate oncogenic pathways in HCC. We also identify a small molecule kinase inhibitor of EphA2 that suppresses tumor progression in a murine HCC model. Together, our results suggest EphA2 as a promising therapeutic target for HCC.

Signal transduction pathway mutations in gastrointestinal (GI) cancers: a systematic review and meta-analysis

The present study was conducted to evaluate the prevalence of the signaling pathways mutation rate in the Gastrointestinal (GI) tract cancers in a systematic review and meta-analysis study. The study was performed based on the PRISMA criteria. Random models by confidence interval (CI: 95%) were used to calculate the pooled estimate of prevalence via Metaprop command. The pooled prevalence indices of signal transduction pathway mutations in gastric cancer, liver cancer, colorectal cancer, and pancreatic cancer were 5% (95% CI: 3-8%), 12% (95% CI: 8-18%), 17% (95% CI: 14-20%), and 20% (95% CI: 5-41%), respectively. Also, the mutation rates for Wnt pathway and MAPK pathway were calculated to be 23% (95% CI, 14-33%) and 20% (95% CI, 17-24%), respectively. Moreover, the most popular genes were APC (in Wnt pathway), KRAS (in MAPK pathway) and PIK3CA (in PI3K pathway) in the colorectal cancer, pancreatic cancer, and gastric cancer while they were beta-catenin and CTNNB1 in liver cancer. The most altered pathway was Wnt pathway followed by the MAPK pathway. In addition, pancreatic cancer was found to be higher under the pressure of mutation compared with others based on pooled prevalence analysis. Finally, APC mutations in colorectal cancer, KRAS in gastric cancer, and pancreatic cancer were mostly associated gene alterations.

CTNNB1 mutation suppresses infiltration of immune cells in hepatocellular carcinoma through miRNA-mediated regulation of chemokine expression

Mutations in the CTNNB1 gene in hepatocellular carcinoma (HCC) are related to immune exclusion, and HCC patients with CTNNB1 mutations tend to be primarily resistant to anti-PD1 therapy. However, systemic evaluation of immune cell infiltration in HCC with mutant CTNNB1 is lacking, and the mechanism of immune exclusion resulting from CTNNB1 mutations remains unclear. Based on CTNNB1 mutation status in HCC, we investigated RNA and miRNA expression and infiltration of immune cells. Data downloaded from TCGA showed that HCC with CTNNB1 mutation had an increased expression of CTNNB1. HCC with CTNNB1 mutation showed a reduction in infiltration score as well as in abundance of certain kinds of immune cells, including CD4 naïve T cells, CD4+ T cells, Tex cells, Th2 cells, Tfh cells, B cells, macrophages, and NK cells. Furthermore, there were 13 chemokines downregulated among all the 14 differentially expressed chemokines (DE-CKs) in CTNNB1 mutants compared to those in the wild type. A positive correlation was found between the expression of DE-CKs and infiltration score, as well as infiltration level of 6 types of immune cells, namely B cells, CD8+ cells, CD4+ cells, macrophages, neutrophils, and dendritic cells. Additionally, 302 differentially expressed immune-related genes (DE-IRGs) were involved mainly in the human immune response and cytokine-cytokine receptor interaction. The target DE-IRGs of differentially expressed miRNAs (DE-miRNAs) were identified and used to construct a network with DE-miRNAs and DE-CKs. Overall, CTNNB1 mutation in HCC led to a decrease in chemokine expression and subsequent suppression of immune cell infiltration partly through regulating specific miRNA-IRG-CK axes, pointing to a potential combination of interference of Wnt/β-catenin signaling with immunotherapy in HCC with CTNNB1 mutation.

β-catenin S45F mutation results in apoptotic resistance

Wnt/β-catenin signaling is one of the key cascades regulating embryogenesis and tissue homeostasis; it has also been intimately associated with carcinogenesis. This pathway is deregulated in several tumors, including colorectal cancer, breast cancer, and desmoid tumors. It has been shown that CTNNB1 exon 3 mutations are associated with an aggressive phenotype in several of these tumor types and may be associated with therapeutic tolerance. Desmoid tumors typically have a stable genome with β-catenin mutations as a main feature, making these tumors an ideal model to study the changes associated with different types of β-catenin mutations. Here, we show that the apoptosis mechanism is deregulated in β-catenin S45F mutants, resulting in decreased induction of apoptosis in these cells. Our findings also demonstrate that RUNX3 plays a pivotal role in the inhibition of apoptosis found in the β-catenin S45F mutants. Restoration of RUNX3 overcomes this inhibition in the S45F mutants, highlighting it as a potential therapeutic target for malignancies harboring this specific CTNNB1 mutation. While the regulatory effect of RUNX3 in β-catenin is already known, our results suggest the possibility of a feedback loop involving these two genes, with the CTNNB1 S45F mutation downregulating expression of RUNX3, thus providing additional possible novel therapeutic targets for tumors having deregulated Wnt/β-catenin signaling induced by this mutation.

Investigation of CTNNB1 gene mutations and expression in hepatocellular carcinoma and cirrhosis in association with hepatitis B virus infection

Hepatitis B virus (HBV), along with Hepatitis C virus chronic infection, represents a major risk factor for hepatocellular carcinoma (HCC) development. However, molecular mechanisms involved in the development of HCC are not yet completely understood. Recent studies have indicated that mutations in CTNNB1 gene encoding for β-catenin protein lead to aberrant activation of the Wnt/ β-catenin pathway. The mutations in turn activate several downstream genes, including c-Myc, promoting the neoplastic process. The present study evaluated the mutational profile of the CTNNB1 gene and expression levels of CTNNB1 and c-Myc genes in HBV-related HCC, as well as in cirrhotic and control tissues. Mutational analysis of the β-catenin gene and HBV genotyping were conducted by direct sequencing. Expression of β-catenin and c-Myc genes was assessed using real-time PCR. Among the HCC cases, 18.1% showed missense point mutation in exon 3 of CTNNB1, more frequently in codons 32, 33, 38 and 45. The frequency of mutation in the hotspots of exon 3 was significantly higher in non-viral HCCs (29.4%) rather than HBV-related cases (12.7%, P = 0.021). The expression of β-catenin and c-Myc genes was found upregulated in cirrhotic tissues in association with HBV infection. Mutations at both phosphorylation and neighboring sites were associated with increased activity of the Wnt pathway. The results demonstrated that mutated β-catenin caused activation of the Wnt pathway, but the rate of CTNNB1 gene mutations was not related to HBV infection. HBV factors may deregulate the Wnt pathway by causing epigenetic alterations in the HBV-related HCC.

Lipid Metabolism in Development and Progression of Hepatocellular Carcinoma

: Metabolic reprogramming is critically involved in the development and progression of cancer. In particular, lipid metabolism has been investigated as a source of energy, micro-environmental adaptation, and cell signalling in neoplastic cells. However, the specific role of lipid metabolism dysregulation in hepatocellular carcinoma (HCC) has not been widely described yet. Alterations in fatty acid synthesis, β-oxidation, and cellular lipidic composition contribute to initiation and progression of HCC. The aim of this review is to elucidate the mechanisms by which lipid metabolism is involved in hepatocarcinogenesis and tumour adaptation to different conditions, focusing on the transcriptional aberrations with new insights in lipidomics and lipid zonation. This will help detect new putative therapeutic approaches in the second most frequent cause of cancer-related death.

OGDHL silencing promotes hepatocellular carcinoma by reprogramming glutamine metabolism

BACKGROUND & AIMS

Mitochondrial dysfunction and subsequent metabolic deregulation are commonly observed in cancers, including hepatocellular carcinoma (HCC). When mitochondrial function is impaired, reductive glutamine metabolism is a major cellular carbon source for de novo lipogenesis to support cancer cell growth. The underlying regulators of reductively metabolized glutamine in mitochondrial dysfunction are not completely understood in tumorigenesis.

METHODS

We systematically investigated the role of oxoglutarate dehydrogenase-like (OGDHL), one of the rate-limiting components of the key mitochondrial multi-enzyme OGDH complex (OGDHC), in the regulation of lipid metabolism in hepatoma cells and mouse xenograft models.

RESULTS

Lower expression of OGDHL was associated with advanced tumor stage, significantly worse survival and more frequent tumor recurrence in 3 independent cohorts totaling 681 postoperative HCC patients. Promoter hypermethylation and DNA copy deletion of OGDHL were independently correlated with reduced OGDHL expression in HCC specimens. Additionally, OGDHL overexpression significantly inhibited the growth of hepatoma cells in mouse xenografts, while knockdown of OGDHL promoted proliferation of hepatoma cells. Mechanistically, OGDHL downregulation upregulated the α-ketoglutarate (αKG):citrate ratio by reducing OGDHC activity, which subsequently drove reductive carboxylation of glutamine-derived αKG via retrograde tricarboxylic acid cycling in hepatoma cells. Notably, silencing of OGDHL activated the mTORC1 signaling pathway in an αKG-dependent manner, inducing transcription of enzymes with key roles in de novo lipogenesis. Meanwhile, metabolic reprogramming in OGDHL-negative hepatoma cells provided an abundant supply of NADPH and glutathione to support the cellular antioxidant system. The reduction of reductive glutamine metabolism through OGDHL overexpression or glutaminase inhibitors sensitized tumor cells to sorafenib, a molecular-targeted therapy for HCC.

CONCLUSION

Our findings established that silencing of OGDHL contributed to HCC development and survival by regulating glutamine metabolic pathways. OGDHL is a promising prognostic biomarker and therapeutic target for HCC.

LAY SUMMARY

Hepatocellular carcinoma (HCC) is one of the most prevalent tumors worldwide and is correlated with a high mortality rate. In patients with HCC, lower expression of the enzyme OGDHL is significantly associated with worse survival. Herein, we show that silencing of OGDHL induces lipogenesis and influences the chemosensitization effect of sorafenib in liver cancer cells by reprogramming glutamine metabolism. OGDHL is a promising prognostic biomarker and potential therapeutic target in OGDHL-negative liver cancer.

Value of T1 mapping on gadoxetic acid-enhanced MRI for microvascular invasion of hepatocellular carcinoma: a retrospective study

BACKGROUND

To evaluate the utility of non-invasive parameters derived from T1 mapping and diffusion-weighted imaging (DWI) on gadoxetic acid-enhanced MRI for predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC).

METHODS

A total of 94 patients with single HCC undergoing partial hepatectomy was analyzed in this retrospective study. Preoperative T1 mapping and DWI on gadoxetic acid-enhanced MRI was performed. The parameters including precontrast, postcontrast and reduction rate of T1 relaxation time and apparent diffusion coefficient (ADC) values were measured for differentiating MVI-positive HCCs (n = 38) from MVI-negative HCCs (n = 56). The receiver operating characteristic curve (ROC) was analyzed to compare the diagnostic performance of the calculated parameters.

RESULTS

MVI-positive HCCs demonstrated a significantly lower reduction rate of T1 relaxation time than that of MVI-negative HCCs (39.4% vs 49.9, P < 0.001). The areas under receiver operating characteristic curve (AUC) were 0.587, 0.728, 0.824, 0,690 and 0.862 for the precontrast, postcontrast, reduction rate of T1 relaxation time, ADC and the combination of reduction rate and ADC, respectively. The cut-off value of the reduction rate and ADC calculated through maximal Youden index in ROC analyses was 44.9% and 1553.5 s/mm². To achieve a better diagnostic performance, the criteria of combining the reduction rate lower than 44.9% and the ADC value lower than 1553.5 s/mm² was proposed with a high specificity of 91.8% and accuracy of 80.9%.

CONCLUSIONS

The proposed criteria of combining the reduction rate of T1 relaxation time lower than 44.9% and the ADC value lower than 1553.5 s/mm² on gadoxetic acid-enhanced MRI holds promise for evaluating MVI status of HCC.

Complement C1q mediates the expansion of periportal hepatic progenitor cells in senescence-associated inflammatory liver

Most hepatocellular carcinomas (HCCs) develop in patients with chronic hepatitis, which creates a microenvironment for the growth of hepatic progenitor cells (HPCs) at the periportal area and subsequent development of HCCs. We investigated the signal from the inflammatory liver for this pathogenic process in the hepatic conditional β-catenin knockout mouse model. Senescent β-catenin-depleted hepatocytes in aged mice create an inflammatory microenvironment that stimulates periportal HPC expansion but arrests differentiation, which predisposes mice to the development of liver tumors. The release of complement C1q from macrophages in the inflammatory niche was identified as the unorthodox signal that activated the β-catenin pathway in periportal HPCs and was responsible for their expansion and de-differentiation. C1q inhibitors blocked the β-catenin pathway in both the expanding HPCs and the liver tumors but spared its orthodox pathway in pericentral normal hepatocytes. This mechanism has been validated in human liver specimens from patients with chronic hepatitis. Taken together, these results demonstrate that C1q- mediated activation of β-catenin pathway in periportal HPCs is a previously unrecognized mechanism for replenishing hepatocytes in the inflammatory liver and, if unchecked, for promoting hepatocarcinogenesis. C1q may become a new target for blocking carcinogenesis in patients with chronic hepatitis.

Glutamine synthetase promotes tumor invasion in hepatocellular carcinoma through mediating epithelial-mesenchymal transition

AIM

Glutamine synthetase (GS) levels increase gradually with the development of hepatocellular carcinogenesis. In this study, we aimed to investigate the clinical significance of GS and the underlying mechanism of GS promoting hepatocellular carcinoma (HCC) invasion.

METHODS

Serum concentration of GS and α-fetoprotein (AFP) in HCC patients, liver cirrhosis patients, and healthy individuals were detected. The GS-mRNA level and its prognostic value were explored in an independent HCC cohort from The Cancer Genome Atlas database. GS expression in HCC tissue and matched para-tumor tissue was determined. The effect of GS on HCC invasion was assessed in vitro and in vivo.

RESULTS

The serum GS and AFP level in HCC patients was higher than that in healthy controls and liver cirrhosis patients. The area under the receiver operating characteristic curve for HCC diagnosis was 0.848 and 0.861 for GS and AFP, respectively. The area under the receiver operating characteristic curve of GS for diagnosis of AFP-negative HCC was 0.913. Combining GS with AFP achieved a diagnostic sensitivity and specificity of 82.5% and 93%, respectively. The GS level was higher in tumor tissues than that in para-tumor tissues. High GS expression was associated with poor prognosis of moderately differentiated HCC patients. In vitro, GS exerted an influence on HCC cell migration by mediating epithelial-mesenchymal transition. The lung and liver metastatic model of HCC further confirmed that GS expression affected the invasion of HCC cells in vivo.

CONCLUSIONS

GS is a useful biomarker for HCC diagnosis, especially for AFP-negative patients. In addition, GS affects HCC metastasis through mediating epithelial-mesenchymal transition.

Heterogeneous beta-catenin activation is sufficient to cause hepatocellular carcinoma in zebrafish

Up to 41% of hepatocellular carcinomas (HCCs) result from activating mutations in the CTNNB1 gene encoding β-catenin. HCC-associated CTNNB1 mutations stabilize the β-catenin protein, leading to nuclear and/or cytoplasmic localization of β-catenin and downstream activation of Wnt target genes. In patient HCC samples, β-catenin nuclear and cytoplasmic localization are typically patchy, even among HCC with highly active CTNNB1 mutations. The functional and clinical relevance of this heterogeneity in β-catenin activation are not well understood. To define mechanisms of β-catenin-driven HCC initiation, we generated a Cre-lox system that enabled switching on activated β-catenin in (1) a small number of hepatocytes in early development; or (2) the majority of hepatocytes in later development or adulthood. We discovered that switching on activated β-catenin in a subset of larval hepatocytes was sufficient to drive HCC initiation. To determine the role of Wnt/β-catenin signaling heterogeneity later in hepatocarcinogenesis, we performed RNA-seq analysis of zebrafish β-catenin-driven HCC. At the single-cell level, 2.9% to 15.2% of hepatocytes from zebrafish β-catenin-driven HCC expressed two or more of the Wnt target genes axin2, mtor, glula, myca and wif1, indicating focal activation of Wnt signaling in established tumors. Thus, heterogeneous β-catenin activation drives HCC initiation and persists throughout hepatocarcinogenesis.

Inhibiting Glutamine-Dependent mTORC1 Activation Ameliorates Liver Cancers Driven by β-Catenin Mutations

Based on their lobule location, hepatocytes display differential gene expression, including pericentral hepatocytes that surround the central vein, which are marked by Wnt-β-catenin signaling. Activating β-catenin mutations occur in a variety of liver tumors, including hepatocellular carcinoma (HCC), but no specific therapies are available to treat these tumor subsets. Here, we identify a positive relationship between β-catenin activation, its transcriptional target glutamine synthetase (GS), and p-mTOR-S2448, an indicator of mTORC1 activation. In normal livers of mice and humans, pericentral hepatocytes were simultaneously GS and p-mTOR-S2448 positive, as were β-catenin-mutated liver tumors. Genetic disruption of β-catenin signaling or GS prevented p-mTOR-S2448 expression, while its forced expression in β-catenin-deficient livers led to ectopic p-mTOR-S2448 expression. Further, we found notable therapeutic benefit of mTORC1 inhibition in mutant-β-catenin-driven HCC through suppression of cell proliferation and survival. Thus, mTORC1 inhibitors could be highly relevant in the treatment of liver tumors that are β-catenin mutated and GS positive.

Promotion of growth factor signaling as a critical function of β-catenin during HCC progression

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. β-catenin is widely thought to be a major oncogene in HCC based on the frequency of mutations associated with aberrant Wnt signaling in HCC patients. Challenging this model, our data reveal that β-catenin nuclear accumulation is restricted to the late stage of the disease. Until then, β-catenin is primarily located at the plasma membrane in complex with multiple cadherin family members where it drives tumor cell survival by enhancing the signaling of growth factor receptors such as EGFR. Therefore, our study reveals the evolving nature of β-catenin in HCC to establish it as a compound tumor promoter during the progression of the disease.

Aberrant Wnt/b-catenin signaling is thought to be a major driver of hepatocellular carcinoma. Here, the authors show that β-Catenin is predominantly integrated within the AJ complex during the early stages of this cancer and enhance EGFR signaling to promote tumour survival.

The Polyploid State Restricts Hepatocyte Proliferation and Liver Regeneration in Mice

The liver contains a mixture of hepatocytes with diploid or polyploid (tetraploid, octaploid, etc.) nuclear content. Polyploid hepatocytes are commonly found in adult mammals, representing ~90% of the entire hepatic pool in rodents. The cellular and molecular mechanisms that regulate polyploidization have been well characterized; however, it is unclear whether diploid and polyploid hepatocytes function similarly in multiple contexts. Answering this question has been challenging because proliferating hepatocytes can increase or decrease ploidy, and animal models with healthy diploid-only livers have not been available. Mice lacking E2f7 and E2f8 in the liver (liver-specific E2f7/E2f8 knockout; LKO) were recently reported to have a polyploidization defect, but were otherwise healthy. Herein, livers from LKO mice were rigorously characterized, demonstrating a 20-fold increase in diploid hepatocytes and maintenance of the diploid state even after extensive proliferation. Livers from LKO mice maintained normal function, but became highly tumorigenic when challenged with tumor-promoting stimuli, suggesting that tumors in LKO mice were driven, at least in part, by diploid hepatocytes capable of rapid proliferation. Indeed, hepatocytes from LKO mice proliferate faster and out-compete control hepatocytes, especially in competitive repopulation studies. In addition, diploid or polyploid hepatocytes from wild-type (WT) mice were examined to eliminate potentially confounding effects associated with E2f7/E2f8 deficiency. WT diploid cells also showed a proliferative advantage, entering and progressing through the cell cycle faster than polyploid cells, both in vitro and during liver regeneration (LR). Diploid and polyploid hepatocytes responded similarly to hepatic mitogens, indicating that proliferation kinetics are unrelated to differential response to growth stimuli. Conclusion: Diploid hepatocytes proliferate faster than polyploids, suggesting that the polyploid state functions as a growth suppressor to restrict proliferation by the majority of hepatocytes.

β-Catenin and Yes-Associated Protein 1 Cooperate in Hepatoblastoma Pathogenesis

Hepatoblastoma (HB), the most common pediatric primary liver neoplasm, shows nuclear localization of β-catenin and yes-associated protein 1 (YAP1) in almost 80% of the cases. Co-expression of constitutively active S127A-YAP1 and ΔN90 deletion-mutant β-catenin (YAP1-ΔN90-β-catenin) causes HB in mice. Because heterogeneity in downstream signaling is being identified owing to mutational differences even in the β-catenin gene alone, we investigated if co-expression of point mutants of β-catenin (S33Y or S45Y) with S127A-YAP1 led to similar tumors as YAP1-ΔN90-β-catenin. Co-expression of S33Y/S45Y-β-catenin and S127A-YAP1 led to activation of Yap and Wnt signaling and development of HB, with 100% mortality by 13 to 14 weeks. Co-expression with YAP1-S45Y/S33Y-β-catenin of the dominant-negative T-cell factor 4 or dominant-negative transcriptional enhanced associate domain 2, the respective surrogate transcription factors, prevented HB development. Although histologically similar, HB in YAP1-S45Y/S33Y-β-catenin, unlike YAP1-ΔN90-β-catenin HB, was glutamine synthetase (GS) positive. However, both ΔN90-β-catenin and point-mutant β-catenin comparably induced GS-luciferase reporter in vitro. Finally, using a previously reported 16-gene signature, it was shown that YAP1-ΔN90-β-catenin HB tumors exhibited genetic similarities with more proliferative, less differentiated, GS-negative HB patient tumors, whereas YAP1-S33Y/S45Y-β-catenin HB exhibited heterogeneity and clustered with both well-differentiated GS-positive and proliferative GS-negative patient tumors. Thus, we demonstrate that β-catenin point mutants can also collaborate with YAP1 in HB development, albeit with a distinct molecular profile from the deletion mutant, which may have implications in both biology and therapy.

Is hepatocellular carcinoma the same disease in children and adults? Comparison of histology, molecular background, and treatment in pediatric and adult patients

Pediatric hepatocellular carcinoma (HCC) is rare, resulting in scattered knowledge of tumor biology and molecular background. Thus far, the variant in children has been treated as a different entity from adult HCC. We weigh the hypothesis that HCC in the pediatric and adult groups may be the same entity and may benefit from the same treatment. Although certain differences between adult and pediatric HCC are obvious and certain types of HCC may ask for a customized approach, in conventional HCC, similarities predominate, warranting treatment aiming at common molecular targets in adult and pediatric HCC patients.

A novel signature derived from immunoregulatory and hypoxia genes predicts prognosis in liver and five other cancers

Background

Despite much progress in cancer research, its incidence and mortality continue to rise. A robust biomarker that would predict tumor behavior is highly desirable and could improve patient treatment and prognosis.

Methods

In a retrospective bioinformatics analysis involving patients with liver cancer (n = 839), we developed a prognostic signature consisting of 45 genes associated with tumor-infiltrating lymphocytes and cellular responses to hypoxia. From this gene set, we were able to identify a second prognostic signature comprised of 8 genes. Its performance was further validated in five other cancers: head and neck (n = 520), renal papillary cell (n = 290), lung (n = 515), pancreas (n = 178) and endometrial (n = 370).

Results

The 45-gene signature predicted overall survival in three liver cancer cohorts: hazard ratio (HR) = 1.82, P = 0.006; HR = 1.84, P = 0.008 and HR = 2.67, P = 0.003. Additionally, the reduced 8-gene signature was sufficient and effective in predicting survival in liver and five other cancers: liver (HR = 2.36, P = 0.0003; HR = 2.43, P = 0.0002 and HR = 3.45, P = 0.0007), head and neck (HR = 1.64, P = 0.004), renal papillary cell (HR = 2.31, P = 0.04), lung (HR = 1.45, P = 0.03), pancreas (HR = 1.96, P = 0.006) and endometrial (HR = 2.33, P = 0.003). Receiver operating characteristic analyses demonstrated both signatures superior performance over current tumor staging parameters. Multivariate Cox regression analyses revealed that both 45-gene and 8-gene signatures were independent of other clinicopathological features in these cancers. Combining the gene signatures with somatic mutation profiles increased their prognostic ability.

Conclusions

This study, to our knowledge, is the first to identify a gene signature uniting both tumor hypoxia and lymphocytic infiltration as a prognostic determinant in six cancer types (n = 2712). The 8-gene signature can be used for patient risk stratification by incorporating hypoxia information to aid clinical decision making.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1775-9) contains supplementary material, which is available to authorized users.

Utilizing ethacrynic acid and ciclopirox olamine in liver cancer

Once aberrantly activated, the Wnt/β-catenin pathway may result in uncontrolled proliferation and eventually cancer. Efforts to counter and inhibit this pathway are mainly directed against β-catenin, as it serves a role on the cytoplasm and the nucleus. In addition, specially-generated lymphocytes are recruited for the purpose of treating liver cancer. Peripheral blood mononuclear lymphocytes are expanded by the timely addition of interferon γ, interleukin (IL)-1β, IL-2 and anti-cluster of differentiation 3 antibody. The resulting cells are called cytokine-induced killer (CIK) cells. The present study utilised these cells and combine them with drugs inhibiting the Wnt pathway in order to examine whether this resulted in an improvement in the killing ability of CIK cells against liver cancer cells. Drugs including ethacrynic acid (EA) and ciclopirox olamine (CPX) were determined to be suitable candidates, as determined by previous studies. Drugs were administered on their own and combined with CIK cells and then a cell viability assay was performed. These results suggest that EA-treated cells demonstrated apoptosis and were significantly affected compared with untreated cells. Unlike EA, CPX killed normal and cancerous cells even at low concentrations. Subsequent to combining EA with CIK cells, the potency of killing was increased and a greater number of cells died, which proves a synergistic action. In summary, EA may be used as an anti-hepatocellular carcinoma drug, while CPX possesses a high toxicity to cancerous as well as to normal cells. It was proposed that EA should be integrated into present therapeutic methods for cancer.

The Effect of Selective c-MET Inhibitor on Hepatocellular Carcinoma in the MET-Active, β-Catenin-Mutated Mouse Model

Simultaneous mutations in CTNNB1 and activation of c-MET occur in 9%-12.5% of patients with hepatocellular carcinoma (HCC). Coexpression of c-MET-V5 and mutant β-catenin-Myc in mouse liver by sleeping beauty transposon/transposase and hydrodynamic tail vein injection (SB-HTVI) led to the development of HCC with 70% molecular identity to the clinical subset. Using this model, we investigated the effect of EMD1214063, a highly selective c-MET inhibitor. Five weeks after SB-HTVI when tumors were established, EMD1214063 (10 mg/kg) was administered by gastric gavage as a single agent on 5-day-on/3-day-off schedule, compared to vehicle only control. Mice were harvested at 8 or 11 weeks posttreatment. Decreased p-MET, p-AKT, p-STAT3, and p-ERK proved in vivo efficacy of EMD1214063. We observed lower Ki-67, PCNA, V5-tag, and cyclin D1 after EMD1214063 treatment only at 8 weeks. Overall, no significant differences were observed in tumor burden between the groups, although EMD1214063 marginally but significantly improved overall survival by 1.5-2 weeks. Tumors remained α-fetoprotein+, did not show any differences in inflammation, and lacked fibrosis in either group. In conclusion, c-MET inhibition alone had a minor effect on Met-β-catenin HCC at the early stages of HCC development. Thus, a single therapy with the c-MET inhibitor will be insufficient for sustained response in Met-β-catenin HCC requiring assessment of additional combinations.

Prognostic significance of c-Met, β-catenin and FAK in patients with hepatocellular carcinoma following surgery

The present study aimed to investigate the prognostic value of specific molecular markers in patients with hepatocellular carcinoma (HCC) who had received surgery. Immunohistochemical analysis was used to measure the expression of hepatocyte growth factor receptor (c-Met), β-catenin and focal adhesion kinase (FAK) in patients with HCC. c-Met expression was identified to be high in patients with larger tumors, higher α-fetoprotein (AFP) levels, higher Edmondson grades, portal vein invasion and higher tumor-node-metastasis (TNM) stages. FAK expression was high in patients with portal vein invasion, higher Edmondson grades and higher TNM stages. β-catenin expression was high in patients with larger tumors, hepatitis B virus (HBV) infection, portal vein invasion, higher Edmondson grades and higher TNM stages. Following multivariate analysis, FAK (P=0.002) and β-catenin (P=0.006) expression levels were demonstrated to be significantly associated with Edmondson grade. Additionally, the tumor size (P=0.009) and HBV infection status (P=0.002) were revealed to be associated with β-catenin expression. Kaplan-Meier survival curve analysis demonstrated that patients with HCC with higher FAK expression, higher β-catenin expression, portal vein invasion, higher Edmondson grades, higher TNM stages, younger ages and higher AFP levels had significantly poorer prognoses. Cox's regression analysis revealed that the survival period was correlated with the Edmondson grade, age, AFP level, and FAK and β-catenin expression. Univariate analysis of c-Met, β-catenin and FAK identified a significant correlation between FAK and β-catenin (P=0.015). Correlation analysis revealed no significant correlation between the three molecular markers, but β-catenin and c-Met were markedly correlated (P=0.052). No significant correlation between FAK, c-Met or β-catenin expression was identified. FAK and β-catenin expression demonstrated a correlation with a range of clinicopathological factors, and high FAK and β-catenin expression levels were identified to be correlated with a poor survival rate of patients with HCC. Thus, patients with higher FAK and β-catenin expression may require more aggressive therapy. The results of the present study suggest that FAK and β-catenin expression possess more prognostic value than c-Met expression in patients with HCC.

Hepatocyte specific expression of an oncogenic variant of β-catenin results in cholestatic liver disease

BACKGROUND

The Wnt/β-catenin signaling pathway plays a crucial role in embryonic development, tissue homeostasis, wound healing and malignant transformation in different organs including the liver. The consequences of continuous β-catenin signaling in hepatocytes remain elusive.

RESULTS

Livers of Ctnnb1CA hep mice were characterized by disturbed liver architecture, proliferating cholangiocytes and biliary type of fibrosis. Serum ALT and bile acid levels were significantly increased in Ctnnb1CA hep mice. The primary bile acid synthesis enzyme Cyp7a1 was increased whereas Cyp27 and Cyp8b1 were reduced in Ctnnb1CA hep mice. Expression of compensatory bile acid transporters including Abcb1, Abcb4, Abcc2 and Abcc4 were significantly increased in Ctnnb1CA hep mice while Ntcp was reduced. Accompanying changes of bile acid transporters favoring excretion of bile acids were observed in intestine and kidneys of Ctnnb1CA hep mice. Additionally, disturbed bile acid regulation through the FXR-FGF15-FGFR4 pathway was observed in mice with activated β-catenin.

MATERIALS AND METHODS

Mice with a loxP-flanked exon 3 of the Ctnnb1 gene were crossed to Albumin-Cre mice to obtain mice with hepatocyte-specific expression of a dominant stable form of β-catenin (Ctnnb1CA hep mice). Ctnnb1CA hep mice were analyzed by histology, serum biochemistry and mRNA profiling.

CONCLUSIONS

Expression of a dominant stable form of β-catenin in hepatocytes results in severe cholestasis and biliary type fibrosis.

Fibrolamellar Carcinoma: Recent Advances and Unresolved Questions on the Molecular Mechanisms

Fibrolamellar hepatocellular carcinoma (FLC) is a rare form of primary liver cancer that affects adolescents and young adults without underlying liver disease. Surgery remains the mainstay of therapy; however, most patients are either not surgical candidates or suffer from recurrence. There is no approved systemic therapy and the overall survival remains poor. Historically classified as a subtype of hepatocellular carcinoma (HCC), FLC has a unique clinical, histological, and molecular presentation. At the genomic level, FLC contains a single 400kB deletion in chromosome 19, leading to a functional DNAJB1-PRKACA fusion protein. In this review, we detail the recent advances in our understanding of the molecular underpinnings of FLC and outline the current knowledge gaps.

Hepatocyte specific expression of an oncogenic variant of β-catenin results in lethal metabolic dysfunction in mice

Background

Wnt/β-catenin signaling plays a crucial role in embryogenesis, tissue homeostasis, metabolism and malignant transformation of different organs including the liver. Continuous β-catenin signaling due to somatic mutations in exon 3 of the Ctnnb1 gene is associated with different liver diseases including cancer and cholestasis.

Results

Expression of a degradation resistant form of β-catenin in hepatocytes resulted in 100% mortality within 31 days after birth. Ctnnb1^CAhep mice were characterized by reduced body weight, significantly enlarged livers with hepatocellular fat accumulation around central veins and increased hepatic triglyceride content. Proteomics analysis using whole liver tissue revealed significant deregulation of proteins involved in fat, glucose and mitochondrial energy metabolism, which was also reflected in morphological anomalies of hepatocellular mitochondria. Key enzymes involved in transport and synthesis of fatty acids and cholesterol were significantly deregulated in livers of Ctnnb1^CAhep mice. Furthermore, carbohydrate metabolism was substantially disturbed in mutant mice.

Conclusion

Continuous β-catenin signaling in hepatocytes results in premature death due to severe disturbances of liver associated metabolic pathways and mitochondrial dysfunction.

Methods

To investigate the influence of permanent β-catenin signaling on liver biology we analyzed mice with hepatocyte specific expression of a dominant stable form of β-catenin (Ctnnb1^CAhep) and their WT littermates by serum biochemistry, histology, electron microscopy, mRNA profiling and proteomic analysis of the liver.