Expression data from normal B cells and chronic lymphocytic leukemia B cells -- with/without treatment of Wnt3a
ABSTRACT: Wnt pathway is dysregulated in CLL-We characterized Wnt pathway gene expression in normal B and CLL-B cells and identified Wnt targets in normal B and CLL-B cells through this data set. In this dataset, we included normal B cells and CLL-B cells for Wnt pathway gene expression. This leads to the identification of 62 Wnt pathway components which are differnetially expressed between normal and CLl-B cells. We also included normal B cells and CLL-B cells with or without Wnt3a treatment and identified 468 and 676 Wnt regulated genes in normal and CLL B cells, respectively. 24 normal B cells and 179 CLL-B cells were used in the Wnt pathway gene expression analysis. Three normal and three CLL samples were included in the identification of Wnt regulated targets
Project description:The Wnt-signalling pathway is one of the core de-regulated pathways in chronic lymphocytic leukemia (CLL), activated in a subset of patients by somatic coding mutations. Here we describe an alternative mechanism of Wnt-activation in malignant B cells, mediated by Notch2 activity in mesenchymal stromal cells (MSC) in the tumor microenvironment. We identified that tumor cells specifically induce and activate Notch2 in MSCs. Notch2 orchestrates the expression of target genes essential for the activation of canonical Wnt-signaling in CLL cells. Mechanistically, stromal Notch2 mediates the stabilization of â-catenin by inhibiting the activation of Gsk3-â in malignant B cells. Pharmacological inhibition of the Wnt-pathway mitigates microenvironment-mediated survival of malignant B cells in vitro. Similarly, inhibition of Notch-signaling impaired survival of CLL cells and disease engraftment in a PDX mouse model. Notch2 activation in the tumour microenvironment is a pre-requisite for the GSK3-â dependent activation of the canonical Wnt-signaling in tumor cells.
Project description:As part of a large genetic evolution study we also acquired 3'UTR expression arrays at two time points for the same 18 patients with CLL. We have analysed the data to evaluate whether genetic evolution (somatic mutations and Somatic copy number alterations) also manifested at the transcriptome level, either globally, or at the level of pre-defined curated geneset that correspond to specfic evolving genetic lesions. Samples were collected at two time points along the patients clinical course, with 13 patients having samples before treatment and at relapse, and 5 patients that were long term non progressors had sampling at two time points without intevening therapy.
Project description:Glioblastoma (GBM) is thought to be driven by a sub-population of cancer stem cells (CSCs) that self-renew and recapitulate tumor heterogeneity, yet remain poorly understood. Here we present a comparative epigenomic analysis of GBM CSCs that reveals widespread activation of genes normally held in check by Polycomb repressors. These activated targets include a large set of developmental transcription factors (TFs) whose coordinated activation is unique to the CSCs. We demonstrate that a critical factor in the set, ASCL1, activates Wnt signaling by repressing the negative regulator DKK1. We show that ASCL1 is essential for maintenance and in vivo tumorigenicity of GBM CSCs. Genomewide binding profiles for ASCL1 and the Wnt effector LEF1 provide mechanistic insight and suggest widespread interactions between the TF module and the signaling pathway. Our findings demonstrate regulatory connections between ASCL1, Wnt signaling and collaborating TFs that are essential for the maintenance and tumorigenicity of GBM CSCs. Two replicates for MGG4, MGG6, MGG23 and NS; four replicates for MGG8
Project description:The tumoral clone of Waldenstrons macroglobulinemia (WM) shows a wide morphological heterogeneity which ranges from B-lymphocytes (BL) to plasma cells (PC). By means of genome-wide expression profiling we have been able to identify genes exclusively deregulated in BL and PC from WM, but with a similar expression pattern in their corresponding cell-counterparts from CLL and MM, as well as normal individuals. The differentially expressed genes have important functions in B-cell differentiation and oncogenesis. Thus, two of the genes down-regulated in WM-BL were IL4R, which plays a relevant role in CLL B cell survival, and BACH2 that participates in the development of class-switched PC. Interestingly, one of the up-regulated genes in WM-BL was IL6. A set of 4 genes was able to discriminate clonal B-lymphocytes from WM and CLL: LEF1 (WNT/ßcatenin pathway), MARCKS, ATXN1 and FMOD. We also found deregulation of genes involved in plasma cell differentiation such as PAX5 which was overexpressed in WM-PC, and IRF4 and BLIMP1 which were underexpressed. In addition, three of the target genes activated by PAX5 -CD79, BLNK and SYK- were up-regulated in WM-PC. In summary, these results indicate that both PC and BL from WM are genetically different from the MM and CLL cell-counterpart. Keywords: Waldenstrons macroglobulinemia, expression profiling, microarrays, Affymetrix. Bone marrow (BM) samples from 10 patients with Waldenstrons macroglobulinemia (WM), 12 with multiple myeloma (MM) and 11 with chronic lymphocytic leukemia (CLL) were included in the study. All samples corresponded to newly diagnosed untreated patients. In addition, 8 normal B lymphocytes samples (NBL) from peripheral blood and 5 normal plasma cells (NPC) from bone marrow of healthy donors were also selected in order to relate the deregulation of GEP of clonal populations to normal condition. The study was approved by the local research ethics committee and written informed consent was obtained from all patients and healthy donors.
Project description:The Wnt/beta-catenin pathway is required for the development of leukemia stem cells in MLL-AF9 AML. We evaluated the dependance on beta-catenin for KrasG12DMLL-AF9 leukemia. Lin-Kit+ bone marrow cells obtained from mice transplanted with primary MLL-AF9 leukemia cells and KRasG12DMLL-AF9 leukemia cells were assessed for gene expression in the presence or absence of beta-catenin
Project description:The Wnt signaling pathway is involved in many differentiation events during embryonic development and can lead to tumor formation after aberrant activation of its components. Β-catenin, a cytoplasmic component, plays a major role in the transduction of the canonical wnt/ β-catenin signaling. The aim of this study was to identify novel genes that are regulated by active β-catenin/TCF signaling in hepatocellular carcinoma. We selected and expanded isogenic clones from hepatocellular carcinoma-derived Huh7 cells with high and low β-catenin/TCF activities. We showed that, high TCF activity Huh7 cells lead to bigger and more aggressive tumors when xenografted into nude mice. We used SAGE (Serial Analysis of Gene Expression), genome-wide microarray and in silico promoter analysis in parallel, to compare gene expression between low (basal) and high (transfected) β-catenin/TCF activity clones, those had been xenografted into nude mice. We compared and contrasted SAGE and genome-wide microarray data, in parallel. Finally; after combined analysis, we identified BRI3 and HSF2 as novel targets of Wnt/β-catenin signaling in hepatocellular carcinoma. Experiment Overall Design: High TCF activity Huh7 cell line (Huh7-S33Y) was compared to control Huh7 cell line (Huh7-Vec) by using 10 ug of total RNA isolated from each sample (15 ug of labeled cRNA was hybridized to the arrays). Triplicates are coming from same total RNA extraction.
Project description:We conducted a genome-wide DNA methylation analysis in CD19+ B-cells from CLL patient and normal control samples using reduced representation bisulfite sequencing (RRBS). The methylation status of 1.8-2.3 million CpGs in the CLL genome was determined; about 45% of these CpGs were located in more than 23,000 CpG islands (CGIs). While global CpG methylation was similar between CLL and normal B-cells, 1764 gene promoters were identified as being differentially methylated between the two groups. Aberrant hypermethylation was found in all HOX gene clusters and a significant number of WNT signaling pathway genes. The genes that were frequently hypermethylated were typically associated with histone H3 lysine 27 tri-methylation or bivalent domains in normal B-cells. An additional 152 genes were found to be differentially methylated between normal naïve and memory B-cells. Of these 152 genes, 123 were hypomethylated in memory B-cells when compared to naïve B-cells. Overall, CLL B-cells had methylation patterns more similar to memory B-cells than naïve B-cells. Cluster analysis showed that the tissue-specific methylated genes separated CLL samples into two groups with differential ZAP70 methylation status. Hypomethylation occurred more frequently in the gene body including introns, exons, and 3'-UTRs in CLL. The hypomethylation in the NFATc1 P2 promoter and first intron correlated with up-regulation of both NFATc1 RNA and protein expression levels in CLL suggesting that an epigenetic mechanism is involved in the constitutive activation of NFAT activity in CLL cells. This comprehensive DNA methylation map will further our understanding of the epigenetic contribution to cellular dysfunction in CLL. To perform a genome-wide analysis of DNA methylation in CLL, we applied the Reduced Representation Bisulfite Sequencing (RRBS) to CD19+ B-cells isolated from normal control and CLL peripheral blood samples. The genomic DNA from each sample was digested with the methylation-insensitive restriction enzyme MspI (restriction site, CCGG) and ligated to Illumina sequencing adaptors containing methylated cytosine residues. The ligated MspI fragments were size-selected, treated with sodium bisulfite, and amplified by PCR. The PCR products were purified and sequenced using Illumina GAIIx sequencer with a read length of 52 or 76bp. 11 CLL B-cell samples, 3 normal control samples including one each of normal CD19+, CD19+/ IgD+ naïve, and CD19+/CD27+ memory B-cell sample and three CLL cell lines (Mec-1, Mec-2, and Wac-3) were used. We generated 20-30 million Illumina sequencing reads for each sample.
Project description:Purpose: The chromosomal deletion 11q affects biology and clinical outcome in CLL but del11q-deregulated genes remain incompletely characterized. Results: We have identified differential expression of the insulin receptor (INSR) in CLL, including high-level INSR expression in the majority of CLL with del11q. High INSR mRNA expression in 11q CLL (~10-fold higher mean levels than other genomic categories) was confirmed by Q-PCR in 247 CLL cases. INSR protein measurements in 257 CLL cases through FACS, compared with measurements in normal CD19+ B-cells and monocytes, confirmed that a subset of CLL aberrantly expresses high INSR levels. We have employed integrated genomic profiling approaches upon CLL cases with and without del11q to identify 11q-relevant genes. Included are 10 primary human cases with del11q and 9 cases without del11q
Project description:Ablation of tetraspanin protein TSPAN12 from human MDA-MB-231 cells resulted in a major decrease in primary tumor xenograft growth, accompanied by a significant increase in tumor apoptosis. Furthermore, TSPAN12 removal markedly increased metastasis to mouse lungs, due to enhanced tumor-endothelial interactions. Removal of TSPAN12 from human MDA-MB-231 cells also caused substantial proteosomal degradation of β-catenin, a key effecter of canonical Wnt signalling. This may be explained by TSPAN12 ablation leading to diminished association between FZD4 (a key receptor in the canonical Wnt pathway) and its co-receptor LRP5. Consistent with disruption of canonical Wnt signaling, TSPAN12 ablation altered the expression of LRP5, Naked 1 and 2, DVL2, DVL3, Axin 1 and GSKβ3 proteins, and also altered expression of several genes regulated by β-catenin. In conclusion, these results provide the first evidence for TSPAN12 playing a role in supporting primary tumor growth and suppressing metastasis. TSPAN12 appears to function by stabilizing FZD4-LRP5 association, in support of canonical Wnt-pathway signaling, leading to enhanced β-catenin expression and function. 4 samples = 2 Control + 2 TSPAN12KD
Project description:Aberrant Shh signaling promotes tumor growth in diverse human cancers. The importance of Shh signaling is particularly evident in medulloblastoma and basal cell carcinoma (BCC), where inhibitors targeting the Shh pathway component Smoothened (Smo) show great therapeutic promise. However, the emergence of drug resistance limits long-term efficacy and the mechanisms of resistance remain poorly understood. Using new culturing techniques, we established a cohort of Shh pathway-driven medulloblastoma cell lines derived from Ptch+/- mice. Using this new model, we identify activation of the RAS/MAPK pathway circumvents Shh pathway-dependency, drives tumor growth and enhances metastatic behavior.Together these findings reveal a critical role of RAS/MAPK pathway in drug resistance and tumor evolution of Shh pathway-dependent tumors. We performed gene expression profile analysis of SMB cells, in vivo primary MB, as well as cerebellum of normal P6 and adult mice. We also compared gene expression profiles of SMB cells to those of growth factor treated and RAS transformed cells. 24 mouse samples were collected for RNA extraction and hybridization on Affymetrix microarrays, including 3 normal cerebellar as control, 3 primary tumor samples and 18 cell samples with different treatment conditions. We first compared gene expression profiles of SMB cells to those of in vivo primary MB and normal cerebellum. We then compared gene expression profiles of SMB cells to those of growth factor treated and RAS transformed cells.