GEP of the murine cell line BAL17 (BALB/c)
Mechanisms of intracerebral lymphoma growth delineated in a syngeneic mouse model of central nervous system lymphoma.
Specimen part
View SamplesThe c-MYC oncogene is a key transcription factor deregulated in most human tumors. Histone marks associated with transcriptionally active genes in euchromatic islands define the set of high-affinity c-MYC targets. The mechanisms involved in their recognition by c-MYC are not known but likely involve chromatin-remodelling and chromatin-modifying complexes. Here, we show that c-MYC interacts with BPTF, a core subunit of the NURF complex that binds active chromatin. BPTF is required for the activation of the full c-MYC transcriptional programme in fibroblasts. BPTF knockdown leads to a decrease in c-MYC recruitment to DNA and to changes in chromatin accessibility. Using BPTF-null MEFs we show that BPTF is necessary for c-MYC-driven proliferation, G1-S progression, and replication stress, but not for c-MYC-driven apoptosis. Consistently, BPTF is required for the proliferation of cells driven by c-MYC, such as Burkitt lymphoma, and its expression in human cancer lines correlates with the activation of c-MYC gene signatures. Our findings point to the c-MYC-BPTF axis as a potential therapeutic target in cancer. Overall design: To assess whether BPTF is required for the transcriptional activity of c-MYC, human foreskin fibroblasts (HFF) were stably transduced with the chimeric MYC-ER cDNA (HFF MYC-ER) and infected with lentiviruses coding for either control (shNt) or BPTF-targeting shRNAs. Cells were serum-starved for 2 days to achieve quiescence and then treated with 4-hydroxytamoxifen (4-OHT)
BPTF is required for c-MYC transcriptional activity and in vivo tumorigenesis.
No sample metadata fields
View SamplesMLL-AF9 expression in normal human umbilical cord blood CD34+ cells leads to long-term proliferation of a myeloid progenitor cell with leukemogenic potential. Expression of a Core Binding Factor leukemia fusion (AML1-ETO or CBFbeta-SMMHC) in human CD34+ cells results in self-renewal of primitive progenitor cells with multilineage potential and stem cell ability, but these cells do not induce leukemia in immunodeficient mice. This comparative microarray study was initiated to determine how faithful these cell cultures are to the transcriptome of patient samples expressing each of these different fusion proteins, and to analyze the signaling pathways that are unique to CBF cultures and MLL-fusion cultures, with the hope of determining why the MLL-fusion cells are leukemogenic while the CBF cells are not.
Microenvironment determines lineage fate in a human model of MLL-AF9 leukemia.
No sample metadata fields
View SamplesAmong B-cell lymphomas mantle cell lymphoma (MCL) has the worst prognosis. By using a combination of genomic and expression profiling (Affymetrix GeneChip Mapping 10k Xba131 and U133 set), we analysed 26 MCL samples to identify genes relevant to MCL pathogenesis and that could represent new therapeutic targets. Recurrent genomic deletions and gains were detected. Genes were identified as overexpressed in regions of DNA gain on 3q, 6p, 8q, 9q, 16p and 18q, including the cancer genes BCL2 and MYC. Among the transcripts with high correlation between DNA and RNA, we identified SYK, a tyrosine kinase involved in B-cell receptor signalling. SYK was amplified at DNA level, as validated by fluorescence in situ hybridisation (FISH) analysis, and overexpressed at both RNA and protein levels in the JeKo-1 cell line. Low-level amplification, with protein overexpression of Syk was demonstrated by FISH in a small subset of clinical samples. After treatment with low doses of the Syk inhibitor piceatannol, cell proliferation arrest and apoptosis were induced in the cell line overexpressing Syk, while cells expressing low levels of Syk were much less sensitive. A combination of genomic and expression profiling suggested Syk inhibition as a new therapeutic strategy to be explored in lymphomas.
Genomic and expression profiling identifies the B-cell associated tyrosine kinase Syk as a possible therapeutic target in mantle cell lymphoma.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.
Sex, Specimen part, Cell line
View SamplesHistone deacetylases (HDACs) have been identified as therapeutic targets due to regulatory function in DNA structure and organization. We have analyzed the role of the LBH589, a novel pan inhibitor of class I and II HDACs, in Acute Lymphoblastic Leukemia. In vitro, LBH589 was shown to induce a dose dependent antiproliferative and apoptotic effect which was associated with an increase in the acetylation of H3 and H4 histone acetylation which was uniformly in every genetic subgroup of ALL. In vivo administration of LBH589 in BALB/c-RAG2-/-c-/- mice in which T and B-cell leukemic cell lines were injected induced a significant reduction in tumor growth (TOM-1, p<0.01 and MOLT-4 p<0.05). Leukemic cells from patients were employed to establish a xenograft model of human leukemia in BALB/c-RAG2-/-c-/- mice and further transplanted in consecutive generations of mice. Treatment of these xenografts with LBH589 induced an increase in the acetylation of H3 and H4 and prolonged the survival of mice in comparison with the animals treated with Vincristine and Dexametasone (p<0.05) and this effect was significantly higher when LBH589 was combined with Vincristine and Dexametasone (p<0.001). Our results that the use of LBH589 in combination with standard chemotherapy represents an attractive option for treatment of patients with ALL.
Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.
Cell line
View SamplesPlants have developed complex mechanisms to respond and adapt to abiotic stresses, coupling elaborate modulation of gene expression together with the preservation of genome stability. Epigenetic mechanisms - DNA methylation, chromatin modifications and non coding RNAs - were shown to play a fundamental role in stress-induced gene regulation and may also result in genome destabilization, with the activation and/or the transcription of silenced transposons and retroelements, causing genome rearrangements and novel gene expression patterns. Maize leaf transcriptome was analyzed by total RNA-Seq in both B73 and rmr6 (PolIV mutant involved in siRNA biogenesis and in the RdDM pathway) after drought and salt stress application. Reference annotation based transcript assembly allowed the identification both of new expressed loci and splicing variants, improving the current maize transcriptome annotation. Many antisense transcripts matching on the opposite strand of annotated loci were also identified, while more than the 20% of transcripts represent non coding RNA belonging to four classes: siRNAs, shRNAs, lncRNAs and transposable elements (or their relics). Several lncRNAs are modulated by stress application while TE-related sequences are mainly expressed in rmr6 and up-regulated by the stress. Overall design: Total RNA-Seq analysis of maize leaves from wt and rmr6-1 mutant plants grown under 1) control conditions, 2) drought stress, 3) salt stress, 4) salt+drought stress. Each condition was investigated in triplicate after 10 days of treatment and after 7 days of recovery. Samples derived from replicates 2 and 3 were pooled and sequenced together
Maize RNA PolIV affects the expression of genes with nearby TE insertions and has a genome-wide repressive impact on transcription.
Treatment, Subject, Time
View SamplesIntrahepatic Cholangiocarcinoma (iCCA) is a deadly disease with rising incidence and few treatment options. Recently, aberrant Notch signaling was reported in iCCA carcinogenesis. Specifically, altered expression and/or activation of the receptors Notch1/2 suggests a role for Notch pathway overactivation during iCCA formation and progression. In this study, we examined the effects of Notch inhibition by γ-secretase inhibitor, LY3039478 in human iCCA cell lines and in an excellent patient derived-xenograft (PDX) model. Expression of several Notch pathway components, including NICD, Hes1, and DLL4, were reduced after GSI treatment. Moreover, LY3039478 inhibits cell migration and invasion while in GSI-treated mice, tumor growth was delayed compared to vehicle and chemotherapy. These results support the notion that Notch inhibition by GSI may reduce in vivo tumorigenesis. In addition, GSI reduces in PDX model VEGFA and MMP13 involved in capillary tube formation and tumor progression. Here, we therefore show a link between the efficacy of Notch inhibition and the tumor microenvironment through LY3039478 that slows tumor progression compared to control mice blocking angiogenesis via MMP13 downregulation.
Crenigacestat, a selective NOTCH1 inhibitor, reduces intrahepatic cholangiocarcinoma progression by blocking VEGFA/DLL4/MMP13 axis.
Specimen part, Treatment
View SamplesDifferences in the inherent properties of undifferentiated fat cell progenitors may contribute to the biological specificity of the abdominal subcutaneous (Sc) and visceral omental (V) fat depots. In this study, the biological characteristics of three distinct subpopulations of adipose tissue-derived stem cells (ASC), i.e. ASCSVF, ASCBottom and ASCCeiling isolated from Sc and V adipose tissue biopsies of non-obese subjects, were investigated. Genome-wide differential gene expression analysis followed by quantitative RT-PCR and analysis of cytokines in the ASC-derived conditioned medium were performed. By analysis of 28,869 annotated genes, 1,019 genes resulted differentially expressed between Sc-ASC and V-ASC. Within the Sc-ASC and V-ASC populations, 546 and 1,222, respectively, were the genes differentially expressed among ASCSVF, ASCBottom and ASCCeiling. A far more striking difference was found when the hierarchical clusters analysis was performed comparing each Sc-ASC with its own homologous V-ASC subset. mRNA levels of HoxA5, Tbx15, PI16, PITPNC1, FABP5, IL-6, IL-8, MCP-1, VEGF, MMP3, TFPI2, and ANXA10 were significantly different between Sc-ASC and V-ASC. Of the 27 cytokines measured, 14 (IL-2, IL-4, IL-5 IL-7, IL-9, IL-10, IL12, IL13, MIP1-, MIP1-, PDGF-, FGFbasic, GM-CSF, IP-10) were not released, whereas 13 were expressed (IL-1beta, IL-1ra, IL-15, IL-17, G-CSF, IFN, RANTES, TNF-, Eotaxin, IL-8, MCP-1, VEGF, IL-6), and of these, MCP-1, Eotaxin, IL-1ra, FGFbasic, IL-6, IL-8, G-CSF, and VEGF were significantly different among ASCSVF, ASCCeiling and ASCBottom of the two adipose tissue depots. These results demonstrate the existence of genetically and functionally heterogeneous fat-derived ASC populations, which may add to the complexity and specificity of Sc and V adipose tissue in humans.
Differences in gene expression and cytokine release profiles highlight the heterogeneity of distinct subsets of adipose tissue-derived stem cells in the subcutaneous and visceral adipose tissue in humans.
Specimen part
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