Project description:Abnormal NF-kB2 activation has been reported in several types of human leukemia and lymphomas although the exact mechanisms and affected pathways are not clear. We have investigated these questions through the use of a unique transgenic mouse model with lymphocyte-targeted expression of p80HT, a lymphoma associated NF-kB2 mutant. Microarray analysis, verified at the RNA and protein level identified new downstream targets and confirmed established regulatory networks. 201 genes were significantly changed, with 126 being upregulated and 75 downregulated. Pathway analysis uncovered both known and unknown interactions between factors important in the development of human B cell lymphomas and multiple myeloma, including cyclins D1 and D2, TRAF1, CD27, BIRC5/survivin, IL-15 and IL-10. Critical roles for STAT3 and TNF receptors are highlighted. Six target genes of STAT3 were identified: cyclins D1and D2, IL-10, survivin, IL-21 and Blimp1. Interfering with STAT3 signaling induced apoptosis in multiple myeloma cell lines. Novel pathways for NF-kB2 are proposed that involve IL-10 and other genes in the differentiation of plasma cells, evasion of apoptosis and proliferation. These pathways were verified with publically available human microarrays. Several treatment strategies based on these findings are discussed.
Project description:Natural killer/T-cell lymphoma (NKTCL) is a malignant proliferation of CD56+/cytoCD3+ lymphocytes and constitutes a heterogeneous group of aggressive lymphomas prevalent in Asian and South American populations. Molecular pathogenesis of NKTCL remains largely elusive. Here we identified somatic mutations in RNA helicase gene DDX3X. Gene expression profiling revealed an association of DDX3X mutations with activation of NF-kB and MAPK pathways. Together, our work suggests the heterogeneity of gene mutational spectrum in NKTCL.
Project description:Abnormal NF-kB2 activation has been reported in several types of human leukemia and lymphomas although the exact mechanisms and affected pathways are not clear. We have investigated these questions through the use of a unique transgenic mouse model with lymphocyte-targeted expression of p80HT, a lymphoma associated NF-kB2 mutant. Microarray analysis, verified at the RNA and protein level identified new downstream targets and confirmed established regulatory networks. 201 genes were significantly changed, with 126 being upregulated and 75 downregulated. Pathway analysis uncovered both known and unknown interactions between factors important in the development of human B cell lymphomas and multiple myeloma, including cyclins D1 and D2, TRAF1, CD27, BIRC5/survivin, IL-15 and IL-10. Critical roles for STAT3 and TNF receptors are highlighted. Six target genes of STAT3 were identified: cyclins D1and D2, IL-10, survivin, IL-21 and Blimp1. Interfering with STAT3 signaling induced apoptosis in multiple myeloma cell lines. Novel pathways for NF-kB2 are proposed that involve IL-10 and other genes in the differentiation of plasma cells, evasion of apoptosis and proliferation. These pathways were verified with publically available human microarrays. Several treatment strategies based on these findings are discussed. RNA was isolated from the B cells of p80HT transgenic mice on the C57BL/6J x SJL/J background , which produced serum monoclonal immunoglobulin (M-protein) (n=3), and the B cells from wild type (WT) littermates (n=3) using Trizol reagent according to the manufacturerM-bM-^@M-^Ys instructions (Invitrogen, Carlsbad, CA). RNA was further prepared with the Ambion WT Expression kit (Life Techologies Corp., Carlsbad, CA) then run on the Mouse Gene 1.0ST microarray chip (Affymetrix, Santa Clara, CA).
Project description:Nodal marginal zone lymphoma (NMZL) is a small B cell neoplasm whose molecular pathogenesis is still essentially unknown and whose differentiation from other small B cell lymphomas is hampered by the lack of specific markers. We have analyzed gene expression, miRNA profile and copy number data from 15 NMZL cases. For comparison, 16 follicular lymphomas, 9 extranodal marginal zone lymphomas, 8 reactive lymph nodes and B-cell subtypes were included. The results were validated by qRT-PCR in an independent series including 61 paraffin-embedded NMZLs. NMZL signature showed an enriched expression of gene sets identifying interleukins, integrins, CD40, PI3K, NF-kB and TGF-Beta; and included genes expressed by normal marginal zone cells and memory B cells. The most highly overexpressed genes were SYK, TACI, CD74, CD82 and CDC42EP5. Genes linked to G2/M and germinal center were downregulated. Comparison of the gene expression profiles of NMZL and FL showed enriched expression of CHIT1, TGFB1 and TACI in NMZL, and BCL6, LMO2 and CD10 in FL. NMZL displayed increased expression of miR-221, miR-223 and let-7f, while FL strongly expressed miR-494. Our study identifies new candidate diagnostic molecules for NMZL and reveals survival pathways activated in NMZL. We have analyzed gene expression, miRNA profile and copy number data from 15 NMZL cases. For comparison, 16 follicular lymphomas, 9 extranodal marginal zone lymphomas, 8 reactive lymph nodes and B-cell subtypes were included. The results were validated by qRT-PCR in an independent series including 61 paraffin-embedded NMZLs
Project description:Molecular signaling that regulates differentiation, survival and proliferation of the prostate luminal epithelial cells has not been thoroughly understood. Herein, we show that increased canonical Notch1 activity suppresses terminal differentiation of prostate luminal epithelial cells but is insufficient to transform. Augmented Notch1 activity delays anoikis of luminal epithelial cells by augmenting NF-κB activity independent of Hes-1, stimulates luminal cell proliferation by potentiating the PI3K-AKT signaling, and rescues the capacities of a fraction of prostate luminal epithelial cells for unipotent differentiation in vivo and short-term self-renewal in vitro. Epithelial cell-autonomous AR signaling is dispensable for the Notch-mediated cellular survival and proliferation. This study reveals a previously unappreciated role of Notch in prostatic luminal epithelial cell differentiation, supports the presence of a lineage hierarchy within the prostate luminal epithelial cells, and implies a pro-metastatic function of Notch signaling during prostate cancer progression. Two group comparison (WT and Mut)
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. 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:Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma in adults. The disease exhibits a striking heterogeneity in gene expression profiles and clinical outcomes, but its genetic causes remain to be fully defined. Through whole genome and exome sequencing, we characterized the genetic diversity of DLBCL. In all, we sequenced 73 DLBCL primary tumors (34 with matched normal DNA). Separately, we sequenced the exomes of 21 DLBCL cell lines. We identified 322 DLBCL cancer genes that were recurrently mutated in primary DLBCLs. We identified recurrent mutations implicating a number of known and not previously identified genes and pathways in DLBCL including those related to chromatin modification (ARID1A and MEF2B), NF-κB (CARD11 and TNFAIP3), PI3 kinase (PIK3CD, PIK3R1, and MTOR), B-cell lineage (IRF8, POU2F2, and GNA13), and WNT signaling (WIF1). We also experimentally validated a mutation in PIK3CD, a gene not previously implicated in lymphomas. The patterns of mutation demonstrated a classic long tail distribution with substantial variation of mutated genes from patient to patient and also between published studies. Thus, our study reveals the tremendous genetic heterogeneity that underlies lymphomas and highlights the need for personalized medicine approaches to treating these patients. 21 DLBCL cell lines and 70 DLBCL patient samples.
Project description:After exiting the thymus, Foxp3+ regulatory T (Treg) cells undergo further differentiation in the periphery resulting in the generation of effector (e)Treg cells, a process dependent on TCR signaling and the transcription factor IRF4. Here we show tumor necrosis factor receptor super family (TNFRSF) signaling plays a crucial role in the development and maintenance of eTreg cells. TNFRSF signaling activated the NF-κB transcription factor RelA and induced expansion and survival of eTreg cells in lymphoid and non-lymphoid tissues, including RORγt+ resident Treg cells in the small intestine. RelA regulated basic cellular processes in Treg cells, including cell survival and proliferation in response to TNFRSF signaling, but was not required for IRF4 expression or DNA binding, indicating that both pathways operate independently. Importantly, a similar pathway appeared to be active in humans, as patients with a point mutation in NF-κB1, a binding partner of RelA, had severely compromised Treg cells. Therefore, although TCR signaling is essential for eTreg cell differentiation, the TNFRSF-NF-κB axis was additionally required in a non-redundant manner to maintain the pool of eTreg cells.
Project description:After exiting the thymus, Foxp3+ regulatory T (Treg) cells undergo further differentiation in the periphery resulting in the generation of effector (e)Treg cells, a process dependent on TCR signaling and the transcription factor IRF4. Here we show tumor necrosis factor receptor super family (TNFRSF) signaling plays a crucial role in the development and maintenance of eTreg cells. TNFRSF signaling activated the NF-κB transcription factor RelA and induced expansion and survival of eTreg cells in lymphoid and non-lymphoid tissues, including RORγt+ resident Treg cells in the small intestine. RelA regulated basic cellular processes in Treg cells, including cell survival and proliferation in response to TNFRSF signaling, but was not required for IRF4 expression or DNA binding, indicating that both pathways operate independently. Importantly, a similar pathway appeared to be active in humans, as patients with a point mutation in NF-κB1, a binding partner of RelA, had severely compromised Treg cells. Therefore, although TCR signaling is essential for eTreg cell differentiation, the TNFRSF-NF-κB axis was additionally required in a non-redundant manner to maintain the pool of eTreg cells.