Project description:Gene expression was analyzed and compared of normal mouse hepatocyte, premalignant hepatocytes and fully malignant HCC cells. The results provide valuable information about the gene expression alterations during the chronic process of liver cancer development. HCC in age-matched male mice were induced by DEN injection. Normal mouse hepatocyte, premalignant hepatocytes and fully malignant HCC were freshly isolated and RNA extracted.
Project description:Gene expression was analyzed and compared of normal mouse hepatocyte, premalignant hepatocytes and fully malignant HCC cells. The results provide valuable information about the gene expression alterations during the chronic process of liver cancer development.
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:Objective: Antigen-specific immunotherapy is a promising strategy to treat hepatitis B virus (HBV) infection and (HBV-related) hepatocellular carcinoma (HCC). To facilitate killing of malignant and/or infected hepatocytes, it is vital to know which T cell targets are presented by HLA-I complexes on patient-derived hepatocytes. Here, we aimed to reveal the hepatocyte-specific HLA-I peptidome with emphasis on peptides derived from HBV proteins and tumor associated antigens (TAAs) to guide development of antigen-specific immunotherapy. Design: Primary human hepatocytes were isolated with high purity from (HBV infected) non-tumor and HCC tissues using a newly designed perfusion-free procedure. Subsequently, hepatocyte-derived HLA-bound peptides were identified by mass spectrometry after which source proteins were subjected to gene ontology and pathway analysis. Finally, all HBV-antigen and TAA-derived HLA-peptides were extracted and a selection was tested for immunogenicity. Results: We acquired a high quality HLA-I peptidome of 2x105 peptides, of which source proteins were associated with hepatocyte function. Importantly, we demonstrated HLA-I presentation of HBV-derived and TAA-derived peptides for the first time in immune cell-depleted primary liver cell isolates. The peptidome included 8 HBV-derived peptides and 14 peptides from 8 known HCC-associated TAAs that were exclusively identified in tumor eluates. Of these, immunogenicity was demonstrated for 5 HBV-derived and 3 TAA-derived peptides. Conclusion: We present a first HLA-I immunopeptidome of isolated primary human hepatocytes, devoid of immune cells. Our results directly aid development of antigen-specific immunotherapy for HBV infection and HCC. Described methodology can also be applied to personalize immunotherapeutic treatment of liver diseases in the future.
Project description:AEG-1 is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC A transgenic mouse with hepatocyte-specific expression of human AEG-1 was generated using mouse albumin promoter/enhancer in B6/CBA background. Hepatocytes were isolated from WT and Alb/AEG-1 mice for RNA extraction and Affymetrix microarray hybridization.
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:This model describes the multistep process that transform a normal cell and its descendants into a malignant tumour by considering three populations: normal, premalignant and cancer cells. Created by COPASI 4.24(Build 197)
Abstract:
Tumorigenesis has been described as a multistep process, where each step is associated with a genetic alteration, in the direction to progressively transform a normal cell and its descendants into a malignant tumour. Into this work, we propose a mathematical model for cancer onset and development, considering three populations: normal, premalignant and cancer cells. The model takes into account three hallmarks of cancer: self-sufficiency on growth signals, insensibility to anti-growth signals and evading apoptosis. By using a nonlinear expression to describe the mutation from premalignant to cancer cells, the model includes genetic instability as an enabling characteristic of tumour progression. Mathematical analysis was performed in detail. Results indicate that apoptosis and tissue repair system are the first barriers against tumour progression. One of these mechanisms must be corrupted for cancer to develop from a single mutant cell. The results also show that the presence of aggressive cancer cells opens way to survival of less adapted premalignant cells. Numerical simulations were performed with parameter values based on experimental data of breast cancer, and the necessary time taken for cancer to reach a detectable size from a single mutant cell was estimated with respect to some parameters. We find that the rates of apoptosis and mutations have a large influence on the pace of tumour progression and on the time it takes to become clinically detectable.
Project description:Background:
HCC incidence is increasing worldwide due to the obesity epidemic, which drives metabolic dysfunction-associated steatohepatitis (MASH) that can lead to HCC. However, the molecular pathways driving MASH-HCC are poorly understood. We have previously reported that male mice with haploinsufficiency of hypoxia-associated factor, HAF (SART1+/-) spontaneously develop MASH-HCC. However, the cell type(s) responsible for HCC associated with HAF loss are unclear.
Results:
We generated SART1-floxed mice, which were crossed with mice expressing Cre-recombinase within hepatocytes (Alb-Cre; hepS-/-) or myeloid cells (LysM-Cre, macS-/-). HepS-/- mice (both male and female) developed HCC associated with profound inflammatory and lipid dysregulation suggesting that HAF protects against HCC primarily within hepatocytes. HAF-deficient hepatocytes showed decreased P-p65 and P-p50 and in many components of the NF-kB pathway, which was recapitulated using HAF siRNA in vitro. HAF depletion also triggered apoptosis, suggesting that HAF protects against HCC by suppressing hepatocyte apoptosis. We show that HAF regulates NF-kB activity by regulating transcription of TRADD and RIPK1. Mice fed a high-fat diet (HFD) showed marked suppression of HAF, P-p65 and TRADD within their livers after 26 weeks, but showed profound upregulation of these proteins after 40 weeks, implicating deregulation of the HAF-NF-kB axis in the progression to MASH. In humans, HAF was significantly decreased in livers with simple steatosis but significantly increased in HCC compared with normal liver.
Conclusions:
HAF is novel transcriptional regulator of the NF-kB pathway and is a key determinant of cell fate during progression to MASH and MASH-HCC.
Project description:Hepatocellular carcinoma (HCC) is frequently characterized by metabolic and immune remodeling in the tumor microenvironment. We previously discovered that liver-specific deletion of fructose-1, 6-bisphphotase 1 (FBP1), a gluconeogenic enzyme ubiquitously suppressed in HCC tissues, promotes liver tumorigenesis, and induces metabolic and immune perturbations closely resembling human HCC. However, the underlying mechanisms remain incompletely understood. Here we reported that FBP1-deficient livers exhibit diminished amounts of natural killer (NK) cells and accelerated tumorigenesis. Using the diethylnitrosamine-induced HCC mouse model, we analyzed potential changes in the immune cell populations purified from control and FBP1-depleted livers and found that NK cells were strongly suppressed. Mechanistically, FBP1 attenuation in hepatocytes derepresses an EZH2-dependent transcriptional program to inhibit PKLR expression. This leads to reduced levels of PKLR cargo proteins sorted into hepatocyte-derived EVs, dampened activity of EV-targeted NK cells, and accelerated liver tumorigenesis. Our study demonstrated that hepatic FBP1 depletion promotes HCC-associated immune remodeling, partly through the transfer of hepatocyte-secreted, PKLR-attenuated EVs to NK cells.
Project description:Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC). Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. We show that YAP functions as a rheostat maintaining metabolic specialization, differentiation and quiescence within the hepatocyte compartment. Importantly, treatment with siRNA-lipid nanoparticles (siRNA-LNPs) targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model (mice with liver-specific Mst1/Mst2 double knockout). Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of positional identity of hepatocytes, supports targeting YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype potentially responsive to this approach. Mice with liver-specific Mst1/Mst2 double-knockout (Adeno-Cre injected Mst1-/-; Mst2Flox/Flox mice) were monitored for the formation of HCC by ultrasound imaging. Animals were then randomized to be treated by intravenous injection of either siYap-LNPs or siLuciferase-LNPs for a period of 9 days.