Transcription profiling of human cutaneous B-cell lymphoma skin punch biopsies, mycosis fungoides (MF) and 3 normal skin biopsies
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ABSTRACT: We studied gene expression profiles of 17 cutaneous B-cell lymphomas that were collected with 4-6 millimeter skin punch biopsies. We also included tissue from 2 cases of mycosis fungoides (MF), 3 normal skin biopsies and 3 tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B-cell lymphoma specimens two specific B-cell differentiation stage signatures of germinal center B-cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B-cell lymphomas had a germinal center B-cell signature while a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B-cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B-cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B-cell lymphomas of the skin and provides a basis for future studies, that may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets.
Project description:We studied gene expression profiles of 17 cutaneous B-cell lymphomas that were collected with 4-6 millimeter skin punch biopsies. We also included tissue from 2 cases of mycosis fungoides (MF), 3 normal skin biopsies and 3 tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B-cell lymphoma specimens two specific B-cell differentiation stage signatures of germinal center B-cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B-cell lymphomas had a germinal center B-cell signature while a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B-cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B-cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B-cell lymphomas of the skin and provides a basis for future studies, that may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
Project description:We studied gene expression profiles of 17 cutaneous B-cell lymphomas that were collected with 4-6 millimeter skin punch biopsies. We also included tissue from 2 cases of mycosis fungoides (MF), 3 normal skin biopsies and 3 tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B-cell lymphoma specimens two specific B-cell differentiation stage signatures of germinal center B-cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B-cell lymphomas had a germinal center B-cell signature while a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B-cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B-cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B-cell lymphomas of the skin and provides a basis for future studies, that may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:Background: Germinal center B-cell (GCB) lymphomas are common in children and adults. The prognosis strongly depends on age. Subgroups of GCB-lymphomas are characterized by chromosomal translocations affecting immunoglobulin (IG) loci leading to oncogene deregulation. Methods: Novel IG translocation partners were cloned within the network “Molecular Mechanisms in Malignant Lymphomas” (MMML) by long-distance inverse polymerase chain reaction. Mature aggressive B-cell lymphomas from the MMML as well as pediatric and adult lymphoma trials were analyzed by fluorescence in situ hybridization (FISH) and immunhistochemistry. Data from 438 MMML cases characterized by gene expression profiling were mined. Results: Cloning of unknown IG partners identified a t(6;14)(p25;q32) juxtaposing the IRF4 oncogene with the IGH-locus as novel recurrent aberration in GCB lymphoma. FISH analyses of 427 mature B-cell lymphomas for IRF4 translocations revealed 20 IG/IRF4 positive lymphomas (17 IGH/IRF4, 2 IGL/IRF4, 1 IGΚ/IRF4). IG/IRF4-positive lymphomas were predominantly GCB-type diffuse large B-cell lymphomas (DLBCL) or follicular lymphoma grade 3, shared overexpression of IRF4/MUM1 and BCL6 and lacked PRDM1/BLIMP1 expression and t(14;18)/BCL2 breaks. BCL6 aberrations were common. The gene expression profile of IG/IRF4-positive lymphomas was different from other subtypes of DLBCL and a classifier for IG/IRF4 positivity containing 27 genes allowed prediction of 3 additional MMML IG/IRF4-positive cases subsequently proven by FISH. IG/IRF4-positivity was associated with a favorable outcome likely due to significant enrichment of IG/IRF4-positive lymphomas in childhood and young adulthood. Conclusions: Our results suggest IRF4 translocations to be primary genetic alterations in a novel molecularly defined subset of GC-derived lymphomas predominantly affecting children. 271 diffuse large B-Cell lymphoma samples were hybridized to HGU133A Affymetrix GeneChips.
Project description:Immunoglobulin gene rearrangement and somatic hypermutation have the potential to create neoantigens in non-Hodgkin B cell lymphoma. However, the presentation of these putative immunoglobulin neoantigens by B cell lymphomas has not been proven. We used MHC immunoprecipitation followed by liquid chromatography and tandem mass spectrometry (LC-MS/MS) to define antigens presented by follicular lymphomas (FL), chronic lymphocytic leukemias (CLL), diffuse large B cell lymphoma (DLBCL) and mantle cell lymphomas (MCL). We found presentation of the clonal immunoglobulin molecule, including neoantigens by both class I and class II MHC, though more commonly in class II MHC. To determine whether B cell activation could promote presentation of immunoglobulin neoantigens, we used a toll-like receptor 9 (TLR9) agonists to upregulate expression of MHC-II. This resulted in enhanced class II MHC presentation of the immunoglobulin variable region including neoantigens. These findings demonstrate that immunoglobulin neoantigens are presented across most subtypes of B cell lymphomas. Activation of lymphoma cells to upregulate antigen presentation boosts presentation of immunoglobulin neoantigens and represents a strategy for augmenting lymphoma immunotherapies.
Project description:<p>Cutaneous diffuse large B cell lymphomas (DLBCL) are aggressive lymphomas with a poor prognosis. To elucidate their genetic bases, we performed whole exome capture and massively parallel sequencing on 19 tumor samples of diffuse large B cell lymphoma, leg type (DLBCL-LT) and 6 samples of secondary cutaneous diffuse large B cell lymphoma, not otherwise specified (DLBCL-NOS). Tumor specimens and their associated sequencing data were from multiple institutions, including Northwestern University (Chicago, IL), Massachusetts General Hospital (Boston, MA), and Medical University of Graz (Graz, Austria).</p>
Project description:The oncogenic microRNA 17-92 cluster is involved in the lymphomagenesis of nodal and systemic B cell lymphomas, but has not been studied so far in primary cutaneous B cell lymphomas. We performed the quantitative analysis of miR-17-92 cluster and its paralogs miR-106a-363 and miR-106b-25 in 22 primary cutaneous diffuse large B-cell lymphomas-leg type (PCLBCL-LT) and 22 primary cutaneous follicle center lymphomas (PCFCL). Mir-20a and miR-106a were overexpressed in PCLBCL-LT compared to PCFCL. Multivariate Cox analysis showed that higher miR-20a and miR-20b were associated with poorer disease-free survival and poorer overall survival, independently of histological type. Gene expression profiling showed underexpression of 8 candidate target genes of miR-20a, miR-20b and miR-106a in PCLBCL-LT compared to PCFCL. Among the candidate target genes, PTEN, NCOA3 and CAPRIN2 were confirmed to be underexpressed in PCLBCL-LT using quantitative RT-PCR of laser-microdissected tumor cells. In multivariate Cox analysis, lower PTEN mRNA expression level was associated with poorer disease-free survival, independently of the histological type. Altogether, this molecular and bioinformatics study of patients’ skin biopsy samples showed that the oncogenic miR-17-92 cluster is involved in cutaneous B cell lymphoma progression, and that the down-regulation of its target gene PTEN is associated with poorer disease-free survival.
Project description:Large cell lymphomas of the gastrointestinal tract are currently regarded as diffuse large B-cell lymphomas despite a more favourable clinical outcome and a lower aggressiveness compared to other nodal and extranodal DLBCL. We compared gene expression profiles of 28 gastrointestinal marginal zone B-cell lymphomas and variants with several other B-cell lymphoma entities such as Burkitt’s lymphoma, nodal DLBCL, follicular lymphoma, mantle cell lymphoma, primary mediastinal B-cell lymphoma and normal B-cell populations. Based on a subset of NF-kappaB target genes, partitioning and hierarchical cluster algorithms were used which led to comparable results. The different B-cell subsets, the Burkitt’s lymphoma, and the small cell lymphomas formed distinct groups, respectively. The DLBCL were subdivided into one group containing only DLBCL samples, one subset clustered together with the PMBL samples, and another one together with the blastic variants of MZBL. These results implicate that extranodal blastic MZBL represent a distinct subgroup of DLBCL.
Project description:Despite all being derived from germinal center B-cells, follicular and diffuse large B-cell lymphomas are biologically and clinically heterogeneous. DNA methylation has emerged as a robust biomarker for classification of solid tumors, but its application to subtype mature B-cell lymphomas is still in its beginning. Therefore, we conducted array-based DNA methylation analyses on 177 molecularly well-characterized mature B-cell lymphomas from the ICGC MMML-Seq project. The Phenotype-Genotype Many-to-Many Relations Analysis machine learning method was applied to identify significant biclusters of CpGs and samples. The analysis revealed 300 CpGs forming four modules, which ordered the lymphomas into seven methylation patterns (MP1-7). These MP1-7 showed significant associations with biological features of the lymphomas. For example, MP1 and MP2 both predominately comprised follicular lymphomas but significantly differed in age at diagnosis and proliferation history. MP4-MP7 consisted mainly of diffuse large B-cell lymphomas but showed differences regarding their cell-of-origin signatures. MP6 showed enrichment of cases with an MCD/C5-like mutational signature with MYD88 alterations as hallmark. The 300 CpGs also segregated apart Burkitt lymphoma and non-malignant B-cell populations. The identified CpG modules and methylation profiles, thus, reflect properties of mature B-cell lymphomas across different biologic layers from age at diagnosis to mutational signatures.
Project description:Ocular adnexal lymphoma is a rare subtype of non-Hodgkin lymphoma. DIA LC-MS of serum samples collected at diagnosis was performed on 38 ocular adnexal lymphomas (28 extranodal marginal zone lymphomas, and 10 diffuse large B-cell lymphomas), and 20 controls (10 idiopathic orbital inflammation, and 10 reactive lymphoid hyperplasia). Complete clinicopathologic features of these patients were collected.
Project description: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.