Project description:The mechanistic links between transcription factors and the epigenetic landscape, which coordinate the deregulation of gene networks during cell transformation are largely unknown. We used an isogenic model of stepwise tumorigenic transformation of human primary cells to monitor the progressive deregulation of gene networks upon immortalization and oncogene-induced transformation. By combining transcriptome and epigenome data for each step during transformation and by integrating transcription factor (TF) - target gene associations, we identified 142 TFs and 24 chromatin remodelers/modifiers (CRMs), which are preferentially associated with specific co-expression paths that originate from deregulated gene programming during tumorigenesis. These TFs are involved in the regulation of divers processes, including cell differentiation, immune response and establishment/modification of the epigenome. Unexpectedly, the analysis of chromatin state dynamics revealed patterns that distinguish groups of genes, which are not only co-regulated but also functionally related. Further decortication of TF targets enabled us to define potential key regulators of cell transformation, which are engaged in RNA metabolism and chromatin remodelling. Our study suggests a direct implication of CRMs in oncogene-induced tumorigenesis and identifies new CRMs involved in this process. This is the first comprehensive view of gene regulatory networks that are altered during the process of stepwise human cellular tumorigenesis in a virtually isogenic system. Examination of 4 different histone modifications marks and RNA PolII in all 3 cell lines of stepwise tumorigenesis model with biological replicates
Project description:The mechanistic links between transcription factors and the epigenetic landscape, which coordinate the deregulation of gene networks during cell transformation are largely unknown. We used an isogenic model of stepwise tumorigenic transformation of human primary cells to monitor the progressive deregulation of gene networks upon immortalization and oncogene-induced transformation. By combining transcriptome and epigenome data for each step during transformation and by integrating transcription factor (TF) - target gene associations, we identified 142 Tfs and 24 chromatin remodelers/modifiers (CRMs), which are preferentially associated with specific co-expression paths that originate from deregulated gene programming during tumorigenesis. These Tfs are involved in the regulation of divers processes, including cell differentiation, immune response and establishment/modification of the epigenome. Unexpectedly, the analysis of chromatin state dynamics revealed patterns that distinguish groups of genes, which are not only co-regulated but also functionally related. Further decortication of TF targets enabled us to define potential key regulators of cell transformation, which are engaged in RNA metabolism and chromatin remodelling. Our study suggests a direct implication of CRMs in oncogene-induced tumorigenesis and identifies new CRMs involved in this process. This is the first comprehensive view of gene regulatory networks that are altered during the process of stepwise human cellular tumorigenesis in a virtually isogenic system. Transcriptional activity in BJEL and BJELM cells has been evaluated and compared with that found in BJ cells; 2 biological replicates per cell line
Project description:The mechanistic links between transcription factors and the epigenetic landscape, which coordinate the deregulation of gene networks during cell transformation are largely unknown. We used an isogenic model of stepwise tumorigenic transformation of human primary cells to monitor the progressive deregulation of gene networks upon immortalization and oncogene-induced transformation. By combining transcriptome and epigenome data for each step during transformation and by integrating transcription factor (TF) - target gene associations, we identified 142 TFs and 24 chromatin remodelers/modifiers (CRMs), which are preferentially associated with specific co-expression paths that originate from deregulated gene programming during tumorigenesis. These TFs are involved in the regulation of divers processes, including cell differentiation, immune response and establishment/modification of the epigenome. Unexpectedly, the analysis of chromatin state dynamics revealed patterns that distinguish groups of genes, which are not only co-regulated but also functionally related. Further decortication of TF targets enabled us to define potential key regulators of cell transformation, which are engaged in RNA metabolism and chromatin remodelling. Our study suggests a direct implication of CRMs in oncogene-induced tumorigenesis and identifies new CRMs involved in this process. This is the first comprehensive view of gene regulatory networks that are altered during the process of stepwise human cellular tumorigenesis in a virtually isogenic system. Affymetrix SNP arrays (250K) were performed according to the manufacturer's directions on DNA extracted from BJ, BJEL and BJELM cells
Project description:Osteoarthritis is a degenerative joint disease that ranks among the leading causes of pain, adult disability, shortening of working life, and socioeconomic costs worldwide. The mechanisms underlying osteoarthritis pathogenesis are yet to be fully elucidated, thus limiting current disease management and treatment. Galectin-1 is an endogenous carbohydrate-binding protein central to adhesion via glycan-bridging, glycoconjugate-mediated signaling, cell proliferation, differentiation, apoptosis, cancers, and host-pathogen interactions. The chondrocyte glycophenotype, which can act as a system of counter-receptors for galectin binding, is compromised in osteoarthritis. We here investigated Galectin-1 and associated gene network's role in human osteoarthritis pathogenesis. Immunohistochemical analysis showed that Galectin-1 associates with osteoarthritic cartilage and subchondral bone histopathology and severity (p<0.0001, n=29 patients). Glycan-dependent Galectin-1 binding to osteoarthritic chondrocytes' cell surface led to marked upregulation of matrix metalloproteinases and activation of NF-κB. Biochemical, molecular and genome-wide analyses showed that Galectin-1 strongly activates a large inflammatory gene network (p<10-16). Bioinformatic analyses of gene promoters up-regulated by Galectin-1 unveiled an overwhelming NF-κB signaling signature. Inhibition of any of several components of the NF-κB pathway using dedicated inhibitors led to dose-dependent impairment of Galectin-1-mediated transcriptional activation. This study identifies for the first time Galectin-1 as an activator of clinically relevant inflammatory-response genes co-regulated by NF-κB. Since inflammation is critical to cartilage degeneration in osteoarthritis, this report is also first to put glycobiology at the center-stage of osteoarthritic cartilage degeneration. Finally, this is the first report to uncover a Galectin-1 gene signature and associated gene network in any biological setting or species. For microarray experiments, osteoarthritic chondrocytes were isolated from five male patients (47-78 years). Following starvation, cells were incubated in the presence of 50 µg/ml recombinant Galectin-1 for 24 h. For each donor population, untreated cells were included as control. In total, 10 samples were analyzed.
Project description:γ-secretase is an intra-membrane-cleaving aspartyl protease implicated in the processing of a wide range of type I membrane proteins including the Notch receptor and the amyloid-β precursor protein (APP). It thus regulates a diverse array of cellular and biological processes including the differentiation of neuronal embryonic stem cells, or intestinal stem cells, with the latter controlling the self-renewing of the intestinal epithelium. Indeed, proteolysis of these proteins by γ-secretase triggers signaling cascades by releasing intracellular domains (ICDs) which, following association with adaptor proteins and nuclear translocation, modulate the transcription of different genes by binding directly to their promoters. The pronounced proliferative and regenerative effects of Notch signaling and its implication in the generation of the Aβ-peptides, makes γ-secretase a therapeutic target for several types of cancer and for Alzheimerâs disease. To investigate the broad effects of γ-secretase activity onto the cellular transcriptome, Chinese hamster ovary (CHO) cells with enhanced γ-secretase were compared to cells with abolished γ-secretase activity via a microarray designed for a genetically close species, mouse. Our findings will potentially help to decipher the biology of γ-secretase, including a better understanding of the roles of this enzyme in gene transcription. We compared the transcriptomes of two CHO cell lines displaying extreme differences in γ-secretase activity. The S-1 cell line overexpressed the four components of γ-secretase (NCT, APH1aL, PS1, and PEN2) and was characterized by a marked increase in the level of PS1 heterodimers associated with 8-fold increased γ-secretase activity compared to untransfected controls. The other cell line consisted of wild type CHO cells incubated with DAPT, a well-known γ-secretase inhibitor. The two cell lines were used in combination with a mouse microarray to analyze gene transcription under enhanced γ-secretase. Two samples, S1 and DAPT treated CHO- were used in biological triplicates each.
Project description:The purpose of this study was to isolate NCSCs from oral mucosa using the neurosphere technique. Total RNA from human oral mucosa stromal cells and sphere-formig oral mucosa stromal cells was collected and compared at their gene expression level. Samples from 3 patients were analysed.
Project description:MCF-7 breast cancer cells were treated with two novel anti-cancer compounds, SIMR_3058 and SIMR_3066, and the metabolome and proteome analysed by LC-MS/MS using a timsTOF.
Project description:Purpose: The physiological cardiac hypertrophy is an adaptive condition that does not associate with myocyte cell death while pathological hypertrophy is a maladaptive condition associated with myocyte cell death. Alpha-2 macroglobulin (α-2M) an acute phase protein induces cardiac hypertrophy via the ERK1,2 and PI3K/Akt signaling. This study is aimed at exploring the miRNome of α-2M induced hypertrophied cardiomyocytes and to understand the role of miRNAs in determination of pathological and physiological hypertrophy. Methods: Hypertrophy was induced in H9c2 cardiomyoblasts using alpha-2 macroglobulin. The induction of hypertrophy is confirmed by microscopy and gene expression studies. Subsequently, the total RNA was isolated and small RNA sequencing was executed in Illumina HiSeq 2000. Results: Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during hypertrophy. Among the differentially expressed candidates, miR-99 family (miR-99a, miR-99b and miR-100) showed significant downregulation upon α-2M treatment while isoproterenol treatment (pathological hypertrophy) upregulated their expression. The binding site for Egr1 transcription factor was identified in the promoter region of miR-99 family, and interestingly all miRNAs with Egr1 binding site proven by ChIP-Seq were downregulated during physiological hypertrophy Conclusions: The results proved Egr-1 mediated regulation of miR-99 family determines the uniqueness of pathological and physiological hypertrophy. Upregulated miR-99 expression during pathological hypertrophy suggests that it can be a valuable diagnostic marker and potential therapeutic target for cardiac hypertrophy and heart failure. Small RNA profiles of control and hypertrophied cardiomyocyte H9c2 cells were generated by deep sequencing using Illumina HiSeq 2000
Project description:Proteomics was carried out to compare the proteomes of wild-type MG1655 E coli with mutants lacking either prominent sRNA, SdsR, OxyS or ZbiJ, or lacking the ubiquitous RNA chaperone proteins hfq, in bacteria that had been exposure to long-term (24hr) nitrogen starvation in Gutnick minimal media. The aim of this was to understand what the regulatory contribution of these three sRNA was to bacteria experiencing long-term nitrogen starvation.
Project description:FOXM1 is a key transcription factor regulating cell cycle progression, DNA damage response, and a host of other hallmark cancer features, but the role of the FOXM1 cistrome in driving estrogen receptor-positive (ER+) vs. ER- breast cancer clinical outcomes remains undefined. Chromatin immunoprecipitation sequencing (ChIP-Seq) coupled with RNA sequencing (RNA-Seq) analyses was used to identify FOXM1 target genes in breast cancer cells (MCF-7) where FOXM1 expression was either induced by cell proliferation or repressed by p53 upregulation.