Project description:Genomic analysis of human hepatocellular carcinoma (HCC) is potentially confounded by the differentiation state of the hepatic cell-of-origin. Here we integrated genomic analysis of mouse HCC (with defined cell-of-origin) along with normal liver development. We found a major shift in expression of Wnt and RXR-α pathway genes (up and down, respectively) coincident with the transition from hepatoblasts to hepatocytes. A combined Wnt and RXR-α gene signature categorized HCCs into two subtypes (high Wnt, low RXR-α and low Wnt, high RXR-α), which matched cell-of-origin in mouse models and the differentiation state of human HCC. Suppression of RXR-α levels in hepatocytes increased Wnt signaling and enhanced tumorigenicity, whereas ligand activation of RXR-α achieved the opposite. These results corroborate that there are two main HCC subtypes that correspond to the degree of hepatocyte differentation and that RXR-α, in part via Wnt signaling, plays a key functional role in the hepatocyte-like subtype and potentially could serve as a selective therapeutic target.
Project description:Genomic analysis of human hepatocellular carcinoma (HCC) is potentially confounded by the differentiation state of the hepatic cell-of-origin. Here we integrated genomic analysis of mouse HCC (with defined cell-of-origin) along with normal liver development. We found a major shift in expression of Wnt and RXR-α pathway genes (up and down, respectively) coincident with the transition from hepatoblasts to hepatocytes. A combined Wnt and RXR-α gene signature categorized HCCs into two subtypes (high Wnt, low RXR-α and low Wnt, high RXR-α), which matched cell-of-origin in mouse models and the differentiation state of human HCC. Suppression of RXR-α levels in hepatocytes increased Wnt signaling and enhanced tumorigenicity, whereas ligand activation of RXR-α achieved the opposite. These results corroborate that there are two main HCC subtypes that correspond to the degree of hepatocyte differentation and that RXR-α, in part via Wnt signaling, plays a key functional role in the hepatocyte-like subtype and potentially could serve as a selective therapeutic target. Total RNA from whole livers taken at different developmental timepoints (embryonic day 14, embryonic day 18, post-natal day 5 and post-natal day 56) along with hepatoblasts isolated from E14 livers and immature hepatocytes isolated from E18 livers was extracted and purified using the Qiagen RNeasy Mini Kit. RNA purity and integrity were assayed by the Bioanalyser 2100 (Agilent Technologies). For each sample, 2 µg of total RNA was reverse transcribed and amplified by using an RNA amplification kit from Ambion. Fifteen micrograms of amplified RNA were labeled by direct chemical coupling to the Cy5 NHS ester (Amersham Biosciences). Normal adult mouse liver (Agilent) was used as control and Cy3 labeled. Labeled RNAs were purified, fragmented, and used as probes to hybridize microarrays. Gene expression profiling was done with the 4x44k mouse Agilent platform. Expression profiling of the 23 human HCC samples was previously described
Project description:ARID1A encodes a subunit of chromatin remodeling SWI/SNF complexes and has recently been suggested to be a tumor suppressor gene based on its loss of function somatic mutations, which are frequently found in various human tumors, including hepatocellular carcinoma (HCC). However, the role and mechanism underlying ARID1A mutations in tumorigenesis remain unclear. Here we show that hepatocyte-specific Arid1a deficiency in mice results in steatohepatitis and HCC development, which are accompanied by increased DNA damage, hepatocyte death, mitochondrial damage, innate immune cell infiltration, and large-cell dysplasia, as well as proinflammatory cytokines, TNF-alpha and IL-6 production, and activation of the STAT3 and NF-kappaB pathways. Interestingly, we found that Arid1a ablation-mediated hepatocyte death and liver inflammation are dependent upon Tp53-Bax proapoptotic signaling. In the absence of Tp53, hepatocyte death, immune cell infiltration, and TNF-alpha and IL-6 production were significantly decreased. This study provides an alternative mechanism by which Arid1a deficiency or loss of function mutations contributes to tumorigenesis.
Project description:Hepatocyte growth factor (HGF) signaling through its receptor Met has been implicated in hepatocellular carcinoma tumorigenesis and progression. Met interaction with integrins is shown to modulate the downstream signaling to Akt and ERK (extracellular-regulated kinase). In this study, we developed a mechanistically detailed systems biology model of HGF/Met signaling pathway that incorporated specific interactions with integrins to investigate the efficacy of integrin-binding peptide, AXT050, as monotherapy and in combination with other therapeutics targeting this pathway. Here we report that the modeled dynamics of the response to AXT050 revealed that receptor trafficking is sufficient to explain the effect of Met-integrin interactions on HGF signaling. Furthermore, the model predicted patient-specific synergy and antagonism of efficacy and potency for combination of AXT050 with sorafenib, cabozantinib, and rilotumumab. Overall, the model provides a valuable framework for studying the efficacy of drugs targeting receptor tyrosine kinase interaction with integrins, and identification of synergistic drug combinations for the patients.
Model is encoded by Johannes and submitted to BioModels by Ahmad Zyoud.
Project description:Chronic liver diseases are worldwide on the rise. Due to the rapidly increasing incidence, in particular in Western countries, non-alcoholic fatty liver disease (NAFLD) is gaining importance. As the disease progresses it can develop into hepatocellular carcinoma. Lipid accumulation in hepatocytes has been identified as the characteristic structural change in NAFLD development, but the molecular mechanisms responsible for disease development remained unresolved. Here, we uncover a strong downregulation of the PI3K-AKT pathway and an upregulation of the MAPK pathway in primary hepatocytes from a preclinical model fed with a Western diet (WD). Dynamic pathway modeling of hepatocyte growth factor (HGF) signal transduction combined with global proteomics identifies that an elevated basal MET phosphorylation rate is the main driver of altered signaling leading to increased proliferation of WD-hepatocytes. Model-adaptation to patient-derived hepatocytes reveals a patient-specific variability in basal MET phosphorylation, which correlates with the outcome of patients after liver surgery. Thus, dysregulated basal MET phosphorylation could be an indicator for the health status of the liver and thereby inform on the risk of a patient to suffer from liver failure after surgery.
Project description:Cell fate plasticity enables development, yet unlocked plasticity is a cancer hallmark. Regulating cell identity requires gene activation and repression. While master regulators induce lineage-specific genes to restrict plasticity, it remains unclear whether unwanted plasticity is actively suppressed by lineage-specific repressors. Here, we computationally predict so-called safeguard repressors for 18 cell types that block phenotypic plasticity lifelong. We validated hepatocyte-specific candidates using reprogramming, revealing that Prospero homeobox protein 1 (PROX1) enhanced hepatocyte identity by direct repression of alternate fate master regulators. In line with patient data, PROX1 overexpression in mice blocked initiation and progression of hepatocellular carcinoma and extended survival. Remarkably, Prox1 depletion caused hepatocyte fate loss in vitro, and promoted transdifferentiation of hepatocellular- to cholangio-carcinoma in vivo. Our findings provide mechanistic evidence for PROX1 as a hepatocyte-specific safeguard and support a model where individual cell type-specific repressors actively suppress plasticity throughout life to safeguard lineage choice and prevent disease.
Project description:Hepatocellular carcinoma (HCC) is a highly heterogeneous disease, and prior attempts to develop genomic-based classification for HCC have yielded highly divergent results, indicating difficulty in identifying unified molecular anatomy. We performed a meta-analysis of gene expression profiles in data sets from eight independent patient cohorts across the world. In addition, aiming to establish the real world applicability of a classification system, we profiled 118 formalin-fixed, paraffin-embedded tissues from an additional patient cohort. A total of 603 patients were analyzed, representing the major etiologies of HCC (hepatitis B and C) collected from Western and Eastern countries. We observed three robust HCC subclasses (termed S1, S2, and S3), each correlated with clinical parameters such as tumor size, extent of cellular differentiation, and serum alpha-fetoprotein levels. An analysis of the components of the signatures indicated that S1 reflected aberrant activation of the WNT signaling pathway, S2 was characterized by proliferation as well as MYC and AKT activation, and S3 was associated with hepatocyte differentiation. Functional studies indicated that the WNT pathway activation signature characteristic of S1 tumors was not simply the result of beta-catenin mutation but rather was the result of transforming growth factor-beta activation, thus representing a new mechanism of WNT pathway activation in HCC. These experiments establish the first consensus classification framework for HCC based on gene expression profiles and highlight the power of integrating multiple data sets to define a robust molecular taxonomy of the disease. Surgically resected 118 tumor tissues from patients with hepatocellular carcinoma (HCC)
Project description:Massive studies have been applied in exploring the factors driving pathogenesis, progression and metastasis of hepatocellular carcinoma. However these studies were inefficient in disclosing the fundamental mechanism which promotes hepatocellular carcinoma. Zinc and zinc-finger proteins have been important in extensive biological processes for human. Supervised machine learning using bootstrapping algorithm on GEO and TCGA transcriptome data for hepatocellular carcinoma identified zinc-finger like protein ZFPL1 as potential hepatocellular carcinoma driver. Further studies validated ZFPL1 significantly promoted progression and metastasis of hepatocellular carcinoma. We performed RNA-seq on si-ZFPL1 xenograft tissue and identified CLDN3 as potential target gene for ZFPL1. Further experiments confirmed interaction between ZFPL1 and WNT signaling pathway markers. Conclusively, these studies indicated the effect and mechanism of ZFPL1 on promoting progression and metastasis of hepatocellular carcinoma and might gap the bridge between zinc-finger like proteins and hepatocellular carcinoma.
Project description:Most patients affected by glycogen storage disease type 1a (GSD-1a), an inherited metabolic disorder caused by mutations in the enzyme glucose-6-phosphatase-alpha (G6Pase- α), develop renal and liver complications, including development of hepatocellular adenoma/carcinoma. The purpose of this study was to identify potential biomarkers of the pathophysiology of the GSD1a affected liver. To this end, we utilized the plasma exosomes of a murine model of GSD-1a, LS-G6pc-/- mice, to uncover microRNA expression modulation associated with the disease. Differentially expressed microRNA between LS-G6pc-/- and wild type mice, LS-G6pc-/- mice with hepatocellular adenoma and LS-G6pc-/- mice without adenoma, and LS-G6pc-/- mice with amyloidosis and LS-G6pc-/- mice without amyloidosis were identified. Pathway analysis demonstrated that the target genes of the differentially expressed miRNAs were significantly enriched for insulin signaling pathway, glucose and lipid metabolism, Wnt-beta catenin, telomere maintenance and hepatocellular carcinoma, and chemokine and immune regulation signaling pathways. While some microRNA were common to the different pathologic conditions, others were unique to cancerous or inflammatory status of the animals. Therefore, the altered expression of several microRNA correlates with various pathologic liver statuses and may help discriminate during the progression of the disease and the development of late GSD1-associated complications.
Project description:Hepatocellular carcinoma (HCC) is the fastest growing cause of cancer-related mortality with limited therapies. While endoplasmic reticulum (ER)-stress and the unfolded protein response (UPR) are implicated in HCC, the involvement of the UPR-transducer activating transcription factor 6 alpha (ATF6α) remains unclear. We generated hepatocyte specific n-ATF6 overexpression transgenic mice via Cre-mediated recombination.