Recruitment of MYC to target genes in ramos and mutu3 cells
Ontology highlight
ABSTRACT: Follicular lymphomas and diffuse large B-cell lymphomas have markedly different biological phenotypes and yet all originate from mature, germinal center B-cells. We hypothesized that alterations in DNA methylation patterning might help explain the clinical heterogeneity of these diseases. We report that intra- and inter-individual patient heterogeneity in cytosine methylation is associated with disease severity, and that methylation heterogeneity originates in germinal centers and is amplified during disease progression. Abnormal methylation patterns differ between chromosomal regions and depend on local gene density and the methylation status of neighboring genes. Lymphomagenic transcriptional regulators, such as BCL6, MYC and EZH2, perturb DNA methylation in a target gene-specific manner. Furthermore, aberrant epigenetic states – especially hypomethylation – tend to spread along DNA in a non-specific manner while insulator elements like CTCF inhibit such spreading. Our findings suggest mechanisms through which altered cytosine methylation contributes to the distinct phenotypes of tumors derived from mature B-cells. Identification of MYC target genes in Burkitt lymphomas by ChIP-on-chip. MYC ChIP-on-chip was done in two Burkitt Lymphoma (BL) cell lines (ramos and mutu3) in duplicate. This submission represents the ChIP-chip component of the study.
Project description:MYC translocations are the biologic hallmark of Burkitt lymphomas but also occur in other mature B-cell lymphomas. If accompanied by chromosomal breaks targeting the BCL2 and/or BCL6 oncogenes, these MYC translocation-positive (MYC+) lymphomas are called double-hit lymphomas (DHLs); otherwise, the term single-hit lymphoma (SHL) is applied. In order to characterize the biologic features of these MYC+ lymphomas other than Burkitt lymphomas, we explored, after exclusion of molecular Burkitt lymphoma (mBL) as defined by gene expression profiling (GEP), the molecular, pathological and clinical aspects of 80 MYC translocation (MYC+) lymphomas (31 SHL, 26 BCL2+/MYC+, 14 BCL6+/MYC+, 6 BCL2+/BCL6+/MYC+ and 3 MYC+ lymphomas with unknown BCL6 status). Comparison of SHL and DHL revealed no difference in frequency of MYC partner (IG/non-IG), genomic complexity or MYC expression and no differences in GEP. DHL showed a more frequent GCB-like GEP and higher IGH and MYC mutation rates. GEP revealed 130 differentially expressed genes between BCL6+/MYC+ and BCL2+/MYC+ DHL. BCL2+/MYC+ DHL showed a more frequent GCB-like GEP. Analysis of all lymphomas according to MYC partner (IG/non-IG) revealed no substantial differences. In contrast to mBL and lymphomas without MYC break, SHL and DHL patients had similar poor outcome. Our data suggest that after excluding mBL, MYC+ lymphomas could be biologically widely lumped without further need for subclassification.
Project description:The distinction between the Burkitt lymphoma and diffuse large B-cell lymphoma is imprecise using current diagnostic criteria. We applied transcriptional and genomic profiling to molecularly define Burkitt lymphoma. Gene expression profiling employing Affymetrix GeneChips (U133A) was performed in 220 mature aggressive B-cell lymphomas, including a core group of eight Burkitt lymphomas, which fulfilled all diagnostic criteria of the WHO classification. A molecular signature of Burkitt lymphoma was generated. Chromosomal abnormalities were detected by interphase fluorescence in-situ hybridization and array comparative genomic hybridization. The molecular Burkitt lymphoma signature identified 44 cases. Fifteen of these cases lacked a morphology typical for Burkitt/Burkitt-like lymphoma. The vast majority (88%) of the 176 lymphomas without the molecular Burkitt lymphoma signature represented diffuse large B-cell lymphomas. In 20% of these cases a MYC break was detectable which was associated with complex chromosomal changes. Our molecular definition of Burkitt lymphoma sharpens and extends the spectrum of Burkitt lymphoma. In mature aggressive B-cell lymphomas without a Burkitt lymphoma signature, a chromosomal break in the MYC locus proved to be associated with adverse clinical outcome. Keywords: Gene expression
Project description:The distinction between the Burkitt lymphoma and diffuse large B-cell lymphoma is imprecise using current diagnostic criteria. We applied transcriptional and genomic profiling to molecularly define Burkitt lymphoma. Gene expression profiling employing Affymetrix GeneChips (U133A) was performed in 220 mature aggressive B-cell lymphomas, including a core group of eight Burkitt lymphomas, which fulfilled all diagnostic criteria of the WHO classification. A molecular signature of Burkitt lymphoma was generated. Chromosomal abnormalities were detected by interphase fluorescence in-situ hybridization and array comparative genomic hybridization. The molecular Burkitt lymphoma signature identified 44 cases. Fifteen of these cases lacked a morphology typical for Burkitt/Burkitt-like lymphoma. The vast majority (88%) of the 176 lymphomas without the molecular Burkitt lymphoma signature represented diffuse large B-cell lymphomas. In 20% of these cases a MYC break was detectable which was associated with complex chromosomal changes. Our molecular definition of Burkitt lymphoma sharpens and extends the spectrum of Burkitt lymphoma. In mature aggressive B-cell lymphomas without a Burkitt lymphoma signature, a chromosomal break in the MYC locus proved to be associated with adverse clinical outcome. Experiment Overall Design: 220 diffuse large B-cell lymphoma and Burkitt lymphoma samples hybridized to 221 HGU133A Affymetrix GeneChips
Project description:MYC translocations are the biologic hallmark of Burkitt lymphomas but also occur in other mature B-cell lymphomas. If accompanied by chromosomal breaks targeting the BCL2 and/or BCL6 oncogenes, these MYC translocation-positive (MYC+) lymphomas are called double-hit lymphomas (DHLs); otherwise, the term single-hit lymphoma (SHL) is applied. In order to characterize the biologic features of these MYC+ lymphomas other than Burkitt lymphomas, we explored, after exclusion of molecular Burkitt lymphoma (mBL) as defined by gene expression profiling (GEP), the molecular, pathological and clinical aspects of 80 MYC translocation (MYC+) lymphomas (31 SHL, 26 BCL2+/MYC+, 14 BCL6+/MYC+, 6 BCL2+/BCL6+/MYC+ and 3 MYC+ lymphomas with unknown BCL6 status). Comparison of SHL and DHL revealed no difference in frequency of MYC partner (IG/non-IG), genomic complexity or MYC expression and no differences in GEP. DHL showed a more frequent GCB-like GEP and higher IGH and MYC mutation rates. GEP revealed 130 differentially expressed genes between BCL6+/MYC+ and BCL2+/MYC+ DHL. BCL2+/MYC+ DHL showed a more frequent GCB-like GEP. Analysis of all lymphomas according to MYC partner (IG/non-IG) revealed no substantial differences. In contrast to mBL and lymphomas without MYC break, SHL and DHL patients had similar poor outcome. Our data suggest that after excluding mBL, MYC+ lymphomas could be biologically widely lumped without further need for subclassification. 32 diffuse large B-cell lymphoma samples were hybridized to HG-U133A Affymetrix GeneChips. In addition, this study contains 30 already published samples, which contribute to GSE4475 (Hummel et al. 2006 (PMID 16760442)), as well as 18 already published samples from GSE22470 (Salaverria et al. 2011 (PMID 21487109)). No re-normalisation of the published samples was performed. The complete dataset representing: (1) the 32 diffuse large B-cell lymphoma Samples, (2) the 30 Samples from GSE4475 and (3) the 18 Samples from GSE22470, is linked below as a supplementary file
Project description:microRNA importance in the myc pathway in Burkitt lymphoma. Gene expression data of Burkitt lymphoma samples and non-tumoral controls. 6 Burkitt lymphomas were compared with 16 non-tumoral controls. Universal Human Reference RNA was used as the reference sample. Significantly deregulated miRNAs were computed using the Significant Analysis of Microarray (SAM) analysis from the TM4 pathway and the limma package.
Project description:c-myc-3'RR mice prone to develop Burkitt lymphoma (BL) were crossed with p53+/- mice in order to obtain c-myc-3'RR/p53+/- mice. These mice develop a wider spectrum of lymphoma including BL, mantle cell lymphoma (MCL) and plasma cell lymphoma (PCL). Transcriptoma analysis of these lymphomas is investigated in these arrays. Four different plasma cell lymphoma (PCL1-4), three different mantle cell lymphoma (MCL1-4) and four different Burkitt lymphoma (BL1-4) were compared.
Project description:microRNA importance in the myc pathway in Burkitt lymphoma. MicroRNA data from the Agilent human miRNA platform. 12 Burkitt lymphomas were compared with 14 non-tumoral controls (lymph nodes, tonsils and CD19+CD10+ sorted cells). Significantly deregulated miRNAs were computed using the Significant Analysis of Microarray (SAM) analysis from the TM4 pathway and the limma package.
Project description:The polycomb group (PcG) protein, EZH2, possesses oncogenic properties for which the underlying mechanism is unclear. In this set of experiments, we sought to identify a robust set of Suz12-occupied gene promoters in prostate cancer cell lines. Genome-wide location analysis (ChIP-chip) of SUZ12 was performed in both the PC3 and LNCaP prostate cancer cell lines using an IgG ChIP-chip as a control. There are total 3 hybridizations, including IgG ChIP-chip of PC3 cells, Suz12 ChIP-chip of PC3 and LNCaP cells.
Project description:Burkitt lymphoma is characterized by deregulation of MYC, but the contribution of other genetic mutations to the disease is largely unknown. Here, we describe the first completely sequenced genome from a Burkitt lymphoma tumor and germline DNA from the same affected individual. We further sequenced the exomes of 59 Burkitt lymphoma tumors and compared them to sequenced exomes from 94 diffuse large B-cell lymphoma (DLBCL) tumors. We identified 70 genes that were recurrently mutated in Burkitt lymphomas, including ID3, GNA13, RET, PIK3R1 and the SWI/SNF genes ARID1A and SMARCA4. Our data implicate a number of genes in cancer for the first time, including CCT6B, SALL3, FTCD and PC. ID3 mutations occurred in 34% of Burkitt lymphomas and not in DLBCLs. We show experimentally that ID3 mutations promote cell cycle progression and proliferation. Our work thus elucidates commonly occurring gene-coding mutations in Burkitt lymphoma and implicates ID3 as a new tumor suppressor gene.
Project description:Burkitt lymphoma is characterized by deregulation of MYC, but the contribution of other genetic mutations to the disease is largely unknown. Here, we describe the first completely sequenced genome from a Burkitt lymphoma tumor and germline DNA from the same affected individual. We further sequenced the exomes of 59 Burkitt lymphoma tumors and compared them to sequenced exomes from 94 diffuse large B-cell lymphoma (DLBCL) tumors. We identified 70 genes that were recurrently mutated in Burkitt lymphomas, including ID3, GNA13, RET, PIK3R1 and the SWI/SNF genes ARID1A and SMARCA4. Our data implicate a number of genes in cancer for the first time, including CCT6B, SALL3, FTCD and PC. ID3 mutations occurred in 34% of Burkitt lymphomas and not in DLBCLs. We show experimentally that ID3 mutations promote cell cycle progression and proliferation. Our work thus elucidates commonly occurring gene-coding mutations in Burkitt lymphoma and implicates ID3 as a new tumor suppressor gene. Gene expression profiling on 21 Burkitt lymphomas was performed using standard Affymetrix protocols as described previously. Briefly, 1 μg of total RNA was reverse transcribed, using oligo(dT) primer to synthesize cDNA. T7 primer was used for in vitro transcription, resulting in labeled cRNA, which was fragmented and hybridized to Affymetrix Whole-Genome Gene 1.0 ST microarrays. Microarrays were washed and scanned, and the data were normalized as described previously.