Project description:Comparison of t(11;18)-positive MALT lymphoma to t(11;18)-negative MALT lymphoma, with a special focus on the NF-KB pathway and it's targets
Project description:Comparison of t(11;18)-positive MALT lymphoma to t(11;18)-negative MALT lymphoma, with a special focus on the NF-KB pathway and it's targets 8 t(11;18)-negative and 6 t(11;18)-positive cases of MALT lymphoma, as well as six spleen control samples (1 mix of spleens and 5 singular spleen samples)
Project description:MALT lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH and t(14;18)(q32;q21)/IGH-MALT1, which commonly activate the NF-κB pathway. Gastric MALT lymphomas harboring such translocation do not respond to H. pylori eradication, while those without translocation can be cured by antibiotics. To understand the molecular mechanism of these different MALT lymphoma subgroups, we performed gene expression profiling analysis of 24 MALT lymphomas (15 translocation-positive, 9 translocation-negative). Gene set enrichment analysis (GSEA) of the NF-κB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions showed that translocation-positive MALT lymphomas are characterized by an enhanced expression of NF-κB target genes, particularly TLR6, CCR2, CD69 and BCL2, while translocation-negative cases were featured by active inflammatory and immune responses, such as IL8, CD86, CD28 and ICOS. Separate analyses of the genes differentially expressed between translocation-positive and negative cases and measurement of gene ontology term in these differentially expressed genes by hypergeometric test reinforced the above findings by GSEA. Finally, expression of TLR6, in the presence of TLR2, enhanced both API2-MALT1 and BCL10 mediated NF-κB activation in vitro. Our findings provide novel insights into the molecular mechanism of MALT lymphomas with and without translocation, potentially explaining their different clinical behaviors. This study compares MALT with other lymphomas, namely follicular lymphomas (FL) and mantle cell lymphomas (MCL), and investigates the molecular mechanisms of the lymphomagenesis between translocation-positive versus -negative MALT lymphoma cases in order to derive the pathways leading to MALT lymphoma pathogenesis. The study uses fresh frozen tissues from 24 MALT lymphoma cases with 7 FL and 7 MCL. Samples were run on the HG-U133A, HG-U133B, and HG-U133 plus2 GeneChips.
Project description:MALT lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH and t(14;18)(q32;q21)/IGH-MALT1, which commonly activate the NF-κB pathway. Gastric MALT lymphomas harboring such translocation do not respond to H. pylori eradication, while those without translocation can be cured by antibiotics. To understand the molecular mechanism of these different MALT lymphoma subgroups, we performed gene expression profiling analysis of 24 MALT lymphomas (15 translocation-positive, 9 translocation-negative). Gene set enrichment analysis (GSEA) of the NF-κB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions showed that translocation-positive MALT lymphomas are characterized by an enhanced expression of NF-κB target genes, particularly TLR6, CCR2, CD69 and BCL2, while translocation-negative cases were featured by active inflammatory and immune responses, such as IL8, CD86, CD28 and ICOS.
Project description:MALT lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH and t(14;18)(q32;q21)/IGH-MALT1, which commonly activate the NF-κB pathway. Gastric MALT lymphomas harboring such translocation do not respond to H. pylori eradication, while those without translocation can be cured by antibiotics. To understand the molecular mechanism of these different MALT lymphoma subgroups, we performed gene expression profiling analysis of 24 MALT lymphomas (15 translocation-positive, 9 translocation-negative). Gene set enrichment analysis (GSEA) of the NF-κB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions showed that translocation-positive MALT lymphomas are characterized by an enhanced expression of NF-κB target genes, particularly TLR6, CCR2, CD69 and BCL2, while translocation-negative cases were featured by active inflammatory and immune responses, such as IL8, CD86, CD28 and ICOS. Separate analyses of the genes differentially expressed between translocation-positive and negative cases and measurement of gene ontology term in these differentially expressed genes by hypergeometric test reinforced the above findings by GSEA. Finally, expression of TLR6, in the presence of TLR2, enhanced both API2-MALT1 and BCL10 mediated NF-κB activation in vitro. Our findings provide novel insights into the molecular mechanism of MALT lymphomas with and without translocation, potentially explaining their different clinical behaviors. This study compares MALT with other lymphomas namely follicular and mantle cell lymphomas, and investigates the molecular mechanisms of the lymphomagenesis between translocation positive versus negative MALT lymphoma cases in order to derive the pathways leading to MALT lymphoma pathogenesis using GSEA, GO, dynamic pathway analysis as well as other bioinformatics analysis. Samples were run on the Affymetrix HG-U133A and HG-U133 plus2 GeneChips.
Project description:MALT lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH and t(14;18)(q32;q21)/IGH-MALT1, which commonly activate the NF-κB pathway. Gastric MALT lymphomas harboring such translocation do not respond to H. pylori eradication, while those without translocation can be cured by antibiotics. To understand the molecular mechanism of these different MALT lymphoma subgroups, we performed gene expression profiling analysis of 24 MALT lymphomas (15 translocation-positive, 9 translocation-negative). Gene set enrichment analysis (GSEA) of the NF-κB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions showed that translocation-positive MALT lymphomas are characterized by an enhanced expression of NF-κB target genes, particularly TLR6, CCR2, CD69 and BCL2, while translocation-negative cases were featured by active inflammatory and immune responses, such as IL8, CD86, CD28 and ICOS. Separate analyses of the genes differentially expressed between translocation-positive and negative cases and measurement of gene ontology term in these differentially expressed genes by hypergeometric test reinforced the above findings by GSEA. Finally, expression of TLR6, in the presence of TLR2, enhanced both API2-MALT1 and BCL10 mediated NF-κB activation in vitro. Our findings provide novel insights into the molecular mechanism of MALT lymphomas with and without translocation, potentially explaining their different clinical behaviors.
Project description:Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by reduced activity of the exocrine glands (principally the salivary and lacrimal glands) due to chronic lymphocytic infiltration. pSS has been closely associated with an enhanced risk of mucosa-associated lymphoid tissue (MALT) lymphoma. However, the dynamic epigenetic changes in gland cells accompanied with this pathogenesis are not fully understood. In present study, the labial gland (LG) and parotid gland (PG) tissues from two pSS patients with lymphoma were harvested including LG with negative anti-SSA/SSB and LG with positive anti-SSA/SSB at the first diagnosis of pSS, as well as PG with and without lymphoma tissues at the second diagnosis of MALT. ChIP-seq of H3K4/9/27/36/79me3 were performed. This data is benefit to advanced understanding the dynamic development of MALT from pSS, emphasizing the importance of epigenetic alterations in regulating transcription during the pathologic process.
Project description:Comparison of gene expression profiling analysis of bone marrow isolated CD34+ cells from patients with MALT lymphoma vs. healthy individuals revealed a large number of differentially expressed genes that included NF-kB target genes, genes involved in inflamatory signalling and immunoglobulin genes, suggesting an early lymphoid B-cell priming. Chromosomal translocations involving MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. However, targeting these translocations to mouse B-cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1+Lin- hematopoietic stem/progenitor cells (HS/PCs), leading to the development of tumors recapitulating the clinical, histopathological and molecular features of human MALT lymphomas. Ablation of the p53 gene induced transformation of MALT lymphoma to diffuse large-cell lymphoma of activated B-cell type (ABC-DLBCL). Human CD34+ cells isolated from MALT lymphoma patients displayed an abnormal transcriptional program that was shared by MALT lymphoma cells, transgenic mouse Sca1+Lin- cells and Sca1-MALT1-induced lymphomas. Our study shows that MALT lymphoma can be modeled in mice by targeting MALT1 oncogene to HS/PCs.
Project description:Attempts at modeling chromosomal translocations involving MALT1 gene, hallmarks of human mucosa-associated lymphoid tissue (MALT) lymphoma, have failed to reproduce the disease in mice. Here we describe a transgenic model in which MALT1 expression was targeted to mouse hematopoietic stem/progenitor cells. In Sca1-MALT1 mice, MALT1 deregulation activated the NF-kappaB pathway in Sca1+ cells, promoting selective B-cell differentiation and mature lymphocyte accumulation in extranodal tissues, progressively leading to the development of clonal B-cell lymphomas. These tumors recapitulated the histopathological features of human MALT lymphomas, presenting typical lymphoepithelial lesions and plasmacytic differentiation. Transcriptional profiling of Sca1-MALT1 murine lymphomas revealed overlapping molecular signatures with human MALT lymphomas, including MALT1-mediated NFkappaB activation, pro-inflammatory signaling and XBP1-induced plasmacytic differentiation. Moreover, murine Malt1 showed proteolytic activity by cleaving Bcl10 in Sca1-MALT1 lymphomas. Our novel technological approach has allowed modeling human MALT lymphoma in mice, which represent unique tools study MALT lymphoma biology and evaluate anti-MALT1 therapies. Keywords: Genetic modification, wt vs. transgenic, disease analysis, MALT lymphoma