Access to follicular dendritic cells is a pivotal step in murine chronic lymphocytic leukemia B cell activation and proliferation
Ontology highlight
ABSTRACT: In human chronic lymphocytic leukemia (CLL) pathogenesis B cell antigen receptor signaling seems important for leukemia B cell ontogeny, whereas the microenvironment influences B cell activation, tumor cell lodging and provision of antigenic stimuli. Using the murine E?-Tcl1 CLL model, we demonstrate that CXCR5-controlled access to follicular dendritic cells (FDCs) confers proliferative stimuli to leukemia B cells. Intravital imaging revealed a marginal zone B cell-like leukemia cell trafficking route. Murine and human CLL cells reciprocally stimulated resident mesenchymal stromal cells through lymphotoxin-?-receptor activation, resulting in CXCL13 secretion and stromal compartment remodeling. Inhibition of lymphotoxin/lymphotoxin-?-receptor signaling or of CXCR5 signaling retards leukemia progression. Thus, CXCR5 activity links tumor cell homing, shaping a survival niche, and access to localized proliferation stimuli. This GEO dataset is comprised of GEP measurements for EµTCL mouse CD5+CD19+ tumor cells and healthy WT controls, including healthy MZB cells and B1 cells. 6 measurements are for WT EµTCL1 mice, 5 for the CXCR5-KO EµTCL1 genotype. MZB and B1 cells were pooled from 15 animals. WT reference was obtained from 5 WT animals
Project description:Diffuse large B-cell lymphoma (DLBCL) represents a heterogeneous diagnostic category with distinct molecular subtypes that can be deM-oM-,M-^Aned by gene expression proM-oM-,M-^Aling. However, even within these deM-oM-,M-^Aned subtypes, heterogeneity prevails. To further elucidate the pathogenesis of these entities, we determined the expression of the tumor suppressor phosphatase and tensin homolog (PTEN) in 248 primary DLBCL patient samples. These analyses revealed that loss of PTEN was detectable in 55% of germinal center B-cell-like (GCB) DLBCLs, whereas this abnormality was found in only 14% of non-GCB DLBCL patient samples. In GCB DLBCL, the PTEN status was inversely correlated with activation of the oncogenic PI3K/ protein kinase B (AKT) pathway in both DLBCL cell lines and primary patient samples. Reexpression of PTEN induced cytotox- icity in PTEN-deM-oM-,M-^Acient GCB DLBCL cell line models by inhibiting PI3K/AKT signaling, indicating an addiction to this pathway in this subset of GCB DLBCLs. PI3K/AKT inhibition induced down-regulation of the transcription factor MYC. Reexpression of MYC rescued GCB DLBCL cells from PTEN-induced toxicity, identifying a regulatory mechanism of MYC expression in DLBCL. Finally, pharmacologic PI3K inhibition resulted in toxicity selectively in PTEN-deM-oM-,M-^Acient GCB DLBCL lines. Collectively, our results indicate that PTEN loss deM-oM-,M-^Anes a PI3K/ AKT-dependent GCB DLBCL subtype that is addicted to PI3K and MYC signaling and suggest that pharmacologic inhibition of PI3K might represent a promising therapeutic approach in these lymphomas. This GEO dataset is comprised of a) GEP measurements for 34 primary DLBCL patient samples plus two reference samples, b) 8 paired GEP measurements of the HT DLBCL cell line and c) aCGH measurements for two DLBCL cell lines in addition to previously published cell lines in GSE43272 (i.e., Sample GSM1059798). All of these data were used in the paper cited below.
Project description:In human chronic lymphocytic leukemia (CLL) pathogenesis B cell antigen receptor signaling seems important for leukemia B cell ontogeny, whereas the microenvironment influences B cell activation, tumor cell lodging and provision of antigenic stimuli. Using the murine Eμ-Tcl1 CLL model, we demonstrate that CXCR5-controlled access to follicular dendritic cells (FDCs) confers proliferative stimuli to leukemia B cells. Intravital imaging revealed a marginal zone B cell-like leukemia cell trafficking route. Murine and human CLL cells reciprocally stimulated resident mesenchymal stromal cells through lymphotoxin-β-receptor activation, resulting in CXCL13 secretion and stromal compartment remodeling. Inhibition of lymphotoxin/lymphotoxin-β-receptor signaling or of CXCR5 signaling retards leukemia progression. Thus, CXCR5 activity links tumor cell homing, shaping a survival niche, and access to localized proliferation stimuli.
Project description:Transcriptional profiling of Murine BaF3 cells infected with MPLW515L grown under either normal conditions (Naive) or in 0.8 uM INCB18424 for 4-6 weeks (Persistent). Naive and Persistent cells were then treated with either DMSO (Control) or 0.8 uM INCB18424 for 4 hours. Goal was to determine transcriptional changes conditioned upon sensitivity/resistance of BaF3 MPLW515L mutants to JAK1/2 specific inhibitor. 3 condition experiment consiting of: 1) Naive cells treated with DMSO (Control) , 2) Naïve cells treated with 0.8 uM INCB18424 for 4 hours (Acute) and 3) Persistent cells treated with 0.8 uM INCB18424 for 4 hours (Persistent). Biological replicates: 3 DMSO control replicates, 3 Acute replicates, 3 Persistent replicates.
Project description:Gene expression analysis of Normal CD34+ Cord Blood and UKE1 cell lines treated with hairpins targeting ASXL1. Two independent studies where 1) CD34+ cord blood from normal donors were treated with either A) GFP Vector or B) ASXL1 specific short hairpin and 2) UKE1 cell lines treated with either A) GFP Vector or B) ASXL1 specific short hairpin.
Project description:Identification of BRD32048 as an inhibitor of ETV1 oncogenic transcription factor. This compound was indentified by small molecule mcroarray (a binding assay). It was able to consistently inhibit an ETV1-dependent MMP1-driven luciferase signal. Its direct binding was validated by Suface plasmon resonance (Biacore assay). It inhibits ETV1-driven invasion in ETV1-dependent cell lines. The goal of this gene expression comparison was to interogate the effects of BRD32048 on the global gene expression and to define the degree to which its siganture overlaps with an ETV1-specific shRNA-induced gene expression signature. The gene expression analysis was performed for two ETV1- dependent cell lines. (a) LNCaP (prostate cancer) uses a DOX-inducible system where two different ETV1sh (sh1117 and sh872) are induced for 4 days. In parallel cells were treated with 20 M-BM-5M BRD32048 for 16 hours. The control was DMSO treated cells. (b) SK-MEL-28 were infected with two different ETV1sh (sh3 and sh5) and selected in puromycin for 4 days. The sh control used was GFPsh. In parallel cells were treated with 20 M-BM-5M BRD32048 for 16 hours. The control was DMSO treated cells. Total RNA was isolated and measured with expression arrays. The data was normalized (see data processing) and the gene expression signatures (fold change >1.5 in either direction) were interested bteween the experimental conditions for each cell line.
Project description:Anti neutrophil cytoplasmic antibody (ANCA) associated vasculitis is the most frequent cause of crescentic glomerulonephritis. Histopathologic features and clinical course of the disease are diverse and judgment of disease activity is often limited due to the lack of reliable activity markers. In order to define potentially new molecular or cellular markers in the kidney which may predict clinical outcome, we performed microarray analyses of renal biopsies from patients with ANCA-associated crescentic glomerulonephritis. We correlated expression profiles with clinical data from our prospective study of patients with renal ANCA disease. The CC chemokine ligand 18 (CCL18) was one of the most up-regulated proteins in kidneys of patients with ANCA-associated crescentic glomerulonephritis. CCL18 producing cells in the kidneys were identified as CD68 and CD209 positive myeloid dendritic cells. The density of CCL18 positive cells correlated with the severity of acute tubular injury and with the impairment of renal function. CCL18 protein levels were elevated in serum samples of patients with renal ANCA disease when compared with patients with non- ANCA-associated crescentic glomerulonephritis. Persistence of high CCL18 serum levels correlated with impairment of renal function and the risk of relapsing disease. Therefore, CCL18 might serve as a marker for persistent disease activity and renal relapses in ANCA-associated vasculitis.
Project description:Alu SINEs are the most numerous frequently occurring transcription units in our genome and possess sequence competence for transcription by RNA Pol III. However, through poorly understood mechanisms, the Alu RNA levels are maintained at very low levels in normal somatic cells with obvious benefits of low rates of Alu retrotransposition and energy-economical deployment of RNA Pol III to the tRNA genes which share promoter structure and polymerase requirements with Alu SINEs. Using comparative ChIP sequencing, we unveil that a repeat binding protein, CGGBP1, binds to the transcriptional regulatory regions of Alu SINEs thereby impeding Alu transcription by inhibiting RNA Pol III recruitment. We show that this Alu-silencing depends on growth factor stimulation of cells and subsequent tyrosine phosphorylation of CGGBP1. Importantly, CGGBP1 ensures a sequence-specific discriminative inhibition of RNA Pol III activity at Alu promoters, while sparing the structurally similar tRNA promoters. Our data suggest that CGGBP1 contributes to growth-related transcription by preventing the hijacking of RNA Pol III by Alu SINEs. This study was used to find out the effect of CGGBP1 on serum-induced changes in gene expression and effect of serum on gene expression regulation by CGGBP1. Gene expression profiling of normal human fibroblasts under 4 different experimental perturbations: serum starvation or serum stimulation and CGGBP1 depletion or normal CGGBP1 levels.
Project description:B cell chronic lymphocytic leukemia - A model with immune response
Seema Nanda 1, , Lisette dePillis 2, and Ami Radunskaya 3,
1.
Tata Institute of Fundamental Research, Centre for Applicable Mathematics, Bangalore 560065, India
2.
Department of Mathematics, Harvey Mudd College, Claremont, CA 91711
3.
Department of Mathematics, Pomona College, Claremont, CA, 91711, United States
Abstract
B cell chronic lymphocytic leukemia (B-CLL) is known to have substantial clinical heterogeneity. There is no cure, but treatments allow for disease management. However, the wide range of clinical courses experienced by B-CLL patients makes prognosis and hence treatment a significant challenge. In an attempt to study disease progression across different patients via a unified yet flexible approach, we present a mathematical model of B-CLL with immune response, that can capture both rapid and slow disease progression. This model includes four different cell populations in the peripheral blood of humans: B-CLL cells, NK cells, cytotoxic T cells and helper T cells. We analyze existing data in the medical literature, determine ranges of values for parameters of the model, and compare our model outcomes to clinical patient data. The goal of this work is to provide a tool that may shed light on factors affecting the course of disease progression in patients. This modeling tool can serve as a foundation upon which future treatments can be based.
Keywords: NK cell, chronic lymphocytic leukemia, mathematical model, T cell., B-CLL.
Project description:Chronic lymphocytic leukemia (CLL) B-cells receive signals from the lymph node and bone marrow (BM) microenvironments that regulate their survival and proliferation. These signals and the pathways that propagate them to the interior of the cell represent potential targets for therapeutic intervention. To characterize the pathways that are activated by the BM microenvironment in CLL cells in vivo, we performed gene expression profiling of tumor cells purified from BM and peripheral blood. Functional classification analysis revealed that the most frequently upregulated genes in BM-CLL cells are genes involved in cell cycle and mitosis. Among the most significantly overexpressed were the Aurora A and B kinases. To investigate whether these kinases could represent potential therapeutic targets in CLL, we performed RNA interference experiments in the CLL cell lines MEC1 and EHEB. Downregulation of Aurora A and B inhibited the proliferation and induced apoptosis in these cells. Similar effects were observed with the pan-Aurora kinase inhibitor VX-680 in primary CLL cells induced to proliferate by CpG-ODN and IL-2. VX-680 also inhibited leukemia growth in vivo in a mouse model of CLL. These data suggest that inhibition of Aurora kinases could represent a potential strategy to selectively target the proliferating compartment in CLL. To identify gene expression related to microenvironmental stimuli in B-cell Chronic Lymphocytic Leukemia (CLL) cells in vivo, expression profiles of CLL cells purified (>95%) from bone marrow (BM) and peripheral blood (PB) were compared. Paired BM and PB samples from 6 individuals were used for this analysis.
Project description:The mutational status of the immunoglobulin heavy chain variable region (IGHV) defines two clinically distinct forms of chronic lymphocytic leukemia (CLL) known as mutated (M-CLL) and un-mutated (UM-CLL). To elucidate the molecular mechanisms underlying the adverse clinical outcome associated with UM-CLL, total proteomes from 9 UM-CLL and 9 M-CLL samples were analysed by isobaric tags for relative and absolute quantification (iTRAQ)-based mass spectrometry. Unsupervised clustering, based on the expression of 3521 identified proteins, separated CLL samples into two groups corresponding to IGHV mutational status. Computational analysis showed that 43 cell migration/adhesion pathways were significantly enriched by 39 differentially expressed proteins, 35 of which were expressed at significantly lower levels in UM-CLL samples. Furthermore, UM-CLL cells under-expressed proteins associated with cytoskeletal remodelling and over-expressed proteins associated with transcriptional and translational activity. Taken together, our findings indicated that UM-CLL cells are less migratory and more adhesive than M-CLL cells, resulting in their retention in lymph nodes where they are exposed to proliferative stimuli. In keeping with this hypothesis, analysis of an extended cohort of 120 CLL patients revealed a strong and specific association between UM-CLL and lymphadenopathy. Our study illustrates the potential of total proteome analysis to elucidate pathogenetic mechanisms in cancer.