Caspases, proteolytic enzymes involved in cell death could play a role independent of cell death in the developing heart
Executioner Caspase-3 and 7 Deficiency Reduces Myocyte Number in the Developing Mouse Heart.
Age, Specimen part
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Induction of hepatocellular carcinoma by in vivo gene targeting.
Age, Specimen part
View SamplesThe distinct phenotypic and prognostic subclasses of human hepatocellular carcinoma (HCC) are difficult to reproduce in animal experiments. Here we have used in vivo gene targeting to insert an enhancer-promoter element at an imprinted chromosome 12 locus in mice, thereby converting ~1 in 20,000 normal hepatocytes into a focus of HCC with a single genetic modification. A 300 kb chromosomal domain containing multiple mRNAs, snoRNAs and microRNAs was activated surrounding the integration site. An identical domain was activated at the syntenic locus in a specific molecular subclass of spontaneous human HCCs with a similar histological phenotype, which was associated with partial loss of DNA methylation. These findings demonstrate the accuracy of in vivo gene targeting in modeling human cancer, and suggest future applications in studying various tumors in diverse animal species. In addition, similar insertion events produced by randomly integrating vectors could be a concern for liver-directed human gene therapy.
Induction of hepatocellular carcinoma by in vivo gene targeting.
Age
View SamplesNotch intracellular domain (NICD) is the active form of the Notch receptor. In this mouse model, NICD is inserted in the Rosa26 locus downstream of a loxP-STOP-LoxP (lsl) sequence and therefore NICD expression is dependant on Cre recombinase expression. These mice are crossed with the AFP-Cre strain that expresses Cre in hepatoblasts due to its regulation by the AFP promoter and albumin enhancer. Mice from 6 to 12 months are sacrificed and liver RNA samples from control monotransgenic Rosa26-lsl-NICD and confirmed HCC lesions from bitransgenic AFP-Cre/Rosa26-lsl-NICD (AFP-NICD) are obtained. Exon expression profiling of these samples are submitted.
Notch signaling is activated in human hepatocellular carcinoma and induces tumor formation in mice.
Age, Specimen part
View SamplesGene expression profiles of 75 tissue samples were analyzed representing the stepwise carcinogenic process from pre-neoplastic lesions (cirrhosis and dysplasia) to HCC, including four neoplastic stages (very early HCC to metastatic tumors) from patients with HCV infection. Gene signatures that accurately reflect the pathological progression of disease at each stage were identified and potential molecular markers for early diagnosis uncovered. Pathway analysis revealed dysregulation of the Notch and Toll-like receptor pathways in cirrhosis, followed by deregulation of several components of the Jak/STAT pathway in early carcinogenesis, then up-regulation of genes involved in DNA replication and repair and cell cycle in late cancerous stages.
Genome-wide molecular profiles of HCV-induced dysplasia and hepatocellular carcinoma.
No sample metadata fields
View SamplesHepatocellular 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.
Integrative transcriptome analysis reveals common molecular subclasses of human hepatocellular carcinoma.
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View SamplesOBJECTIVE: Sorafenib is effective in hepatocellular carcinoma (HCC), but patients ultimately present disease progression. Molecular mechanisms underlying acquired resistance are still unknown. Herein, we characterize the role of tumor-initiating cells (T-ICs) and signaling pathways involved in sorafenib resistance. DESIGN: HCC xenograft mice treated with sorafenib (n=22) were explored for responsiveness (n=5) and acquired resistance (n=17). Mechanism of acquired resistance were assessed by: 1) Role of T-ICs by in vitro sphere formation and in vivo tumorigenesis assays using NOD/SCID mice, 2) Activation of alternative signaling pathways and 3) Efficacy of anti-FGF and anti-IGF drugs in experimental models. Gene expression (microarray, qRT-PCR) and protein analyses (immunohistochemistry, western blot) were conducted. A novel gene signature of sorafenib resistance was generated and tested in 2 independent cohorts. RESULTS: Sorafenib-acquired resistance tumors showed significant enrichment of T-ICs (164 cells needed to create a tumor) vs. sorafenib-sensitive tumors (13400 cells) and non-treated tumors (1292 cells), p<0.001. Tumors with sorafenib-acquired resistance were enriched with IGF and FGF signaling cascades (FDR<0.05). In vitro, cells derived from sorafenib-acquired resistant tumors and two sorafenib-resistant HCC cell lines were responsive to IGF or FGF inhibition. In vivo, FGF blockade delayed tumor growth and improved survival in sorafenib-resistant tumors. A sorafenib-resistance 175-gene signature was characterized by enrichment of progenitor-cell features, aggressive tumoral traits and predicted poor survival in 2 cohorts (n=442 HCC patients). CONCLUSION: Acquired resistance to sorafenib is driven by tumor initiating cells with enrichment of progenitor markers and activation of IGF and FGF signaling. Inhibition of these pathways would benefit a subset of patients after sorafenib progression.
Tumour initiating cells and IGF/FGF signalling contribute to sorafenib resistance in hepatocellular carcinoma.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene-expression signature of vascular invasion in hepatocellular carcinoma.
Sex, Age, Specimen part
View SamplesGenome-wide expression analysis of 228 hepatocellular carcinoma and 168 cirrhotic samples as part of a integrated study of gene expression and DNA-methylation de-regulation in patients with hepatocellular carcinoma
DNA methylation-based prognosis and epidrivers in hepatocellular carcinoma.
Sex, Specimen part, Disease, Subject
View SamplesUHRF1 is an essential regulator of DNA methylation that is highly expressed in many cancers. Using transgenic zebrafish, cultured cells and human tumors, we demonstrate that UHRF1 is an oncogene. RNAseq was used to assess the variation in gene expression between control and experimental samples. Overall design: Total small RNA from 2 batches of Tg(fabp10:has.UHRF1-GFP)High and age matched Tg(fabp10:nls-mCherry) control 5 dpf zebrafish livers was purified for preparation of high-throughput sequencing libraries.
UHRF1 overexpression drives DNA hypomethylation and hepatocellular carcinoma.
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