Project description:Follicular lymphoma is the most common indolent non-Hodgkin's lymphoma involving germinal centre B cells, with a subset of patients undergoing transformation to a diffuse large B-cell lymphoma (DLBCL) morphology for which the clinical outcomes are poor. To elucidate the differences in copy number profiles between FL and tFL groups, we performed Affymetrix SNP 6.0 Array analysis on 31 paired FL-tFL cases. We wanted to identify and compare recurrent somatic copy number alterations (CNAs) between the two groups (FL vs. tFL). In addition, the concordance and discordance in the copy neutral loss of heterozygosity (cnLOH) between the two groups were also investigated to identify recurrent target gene regions.
Project description:Follicular lymphoma is the most common indolent non-Hodgkin's lymphoma involving germinal centre B cells, with a subset of patients undergoing transformation to a diffuse large B-cell lymphoma (DLBCL) morphology for which the clinical outcomes are poor. To elucidate the differences in copy number profiles between FL and tFL groups, we performed Affymetrix SNP 6.0 Array analysis on 31 paired FL-tFL cases. We wanted to identify and compare recurrent somatic copy number alterations (CNAs) between the two groups (FL vs. tFL). In addition, the concordance and discordance in the copy neutral loss of heterozygosity (cnLOH) between the two groups were also investigated to identify recurrent target gene regions. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from follicular lymphoma (FL), transformed follicular lymphoma (tFL) and matching germline (GL) sample (if available). Copy number analysis of Affymetrix SNP 6.0 Array were performed on 91 DNA samples, consisting of 31 patients. Among the 31 patients, 19 had matching germline samples, while 12 had no germline samples. The Log R Ratio (LRR) values and the B Allele Frequency (BAF) values were subsequently calculated to search for copy number aberrations and copy neutral (CN)-LOH in the FL and tFL samples. Paired and unpaired analyses were performed accordingly.
Project description:Diffuse large B-cell lymphoma (DLBCL) is a clinically and biologically heterogeneous disease. We have characterized recurrent copy number alterations (CNAs) in a large series of primary DLBCLs with HD-SNP arrays and the GISTIC algromithm. We evaluated the associations between transcript abundance and the presence of specific CNAs by obtaining RNA profiles on the majority of the primary DLBCLs and integrating the gene expression profiles with the copy number data. High molecular weight DNA and total RNA were extracted from frozen biopsy specimens of newly diagnosed and previously untreated primary DLBCLs according to IRB-approved protocols. DLBCL diagnoses and > 80% tumor involvement were confirmed by expert hematologists. 180 primary DLBCLs and 53 normal DNA samples were profiled on Affymetrix SNP array 6.0. 169 of these primary DLBCLs were RNA profiled, 78 on Affymetrix U133A+B and 91 on U133plus2 arrays.
Project description:Follicular lymphoma (FL) is one of the most common types of indolent B-cell lymphoma in Western countries. FL commonly transforms to more aggressive diffuse large B-cell lymphoma (DLBCL) at reported frequencies between 15 - 60%. We have used microarray comparative genomic hybridisation (aCGH) at 1 Mb resolution to study copy number changes in paired tumor samples (primary FL and a subsequent tDLBCL) as well as de novo DLBCL cases to outline genetic mechanisms of transformation from follicular lymphoma to diffuse large B-cell lymphoma.
Project description:Diffuse large B-cell lymphoma (DLBCL) is a clinically and biologically heterogeneous disease. We have characterized recurrent copy number alterations (CNAs) in a large series of primary DLBCLs with HD-SNP arrays and the GISTIC algromithm. We evaluated the associations between transcript abundance and the presence of specific CNAs by obtaining RNA profiles on the majority of the primary DLBCLs and integrating the gene expression profiles with the copy number data.
Project description:Chronic active B cell receptor (BCR) signaling, a hallmark of the ABC subtype of diffuse large B cell lymphoma (DLBCL), engages the CARD11-MALT1-BCL10 (CBM) adapter complex to activates IkappaB kinase (IKK) and the classical NF-kappaB pathway. Here we show that the CBM complex includes the E3 ubiquitin ligases cIAP1 and cIAP2, which are essential mediators of BCR-dependent NF-kappaB activity in ABC DLBCL. cIAP1/2 attach K63-linked polyubiquitin chains on themselves and on BCL10, resulting in the recruitment of IKK and the linear ubiquitin chain ligase LUBAC, which is essential for IKK activation. SMAC mimetic drugs target cIAP1/2 for destruction, and consequently suppress NF-kappaB and selectively kill BCR-dependent ABC DLBCL lines, supporting their clinical evaluation in patients with ABC DLBCL. Four ABC DLBCL tumor biopsy samples and one ABC DLBCL cell line (YM) (n=5) were analysed for copy number gains using the Affymetrix Genome-Wide Human SNP 6.0 Array. CEL files are being made available through dbGaP
Project description:Follicular lymphoma (FL) is one of the most common types of indolent B-cell lymphoma in Western countries. FL commonly transforms to more aggressive diffuse large B-cell lymphoma (DLBCL) at reported frequencies between 15 - 60%. We have used microarray comparative genomic hybridisation (aCGH) at 1 Mb resolution to study copy number changes in paired tumor samples (primary FL and a subsequent tDLBCL) as well as de novo DLBCL cases to outline genetic mechanisms of transformation from follicular lymphoma to diffuse large B-cell lymphoma. Single hybridization per case. 21 FL, 31 transformed DLBCL, 29 de novo DLBCL (10 GC and 19 non-GC DLBCL). Tumor labelled with Cy5 and reference with Cy3. Mixture of 20 normal male or female genomic DNA was used in sex-mismatched hybridization.
Project description:Deep characterization of a large series of splenic diffuse red pulp lymphomas DNA from 5 tumor samples, corresponding to 4 cases, were analyzed with Affymetrix SNP 6.0 platform for copy number alteration study.
Project description:We performed array comparative genomic hybridization (aCGH) and gene expression profiling in 203 samples of diffuse large B cell lymphoma (DLBCL). By gene expression, at least three molecular subtypes of DLBCL termed as germinal center B cell-like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal B cell lymphoma (PMBL) can be distinguished. Combining gene expression profiling and aCGH, revealed copy number abnormalities that had strikingly different frequencies in the three molecular DLBCL subtypes. These data provide genetic evidence that the DLBCL subtypes are distinct diseases that utilize different oncogenic pathways. Keywords: clinical history design
2008-09-04 | GSE11318 | GEO
Project description:Paired copy number analysis of Diffuse Large B Cell Lymphoma
