The chromosomal translocation t(11;14)(q13;q32) leading to cyclin-D1 over-expression plays an essential role in the development of mantle cell lymphoma (MCL), an aggressive tumor that remains incurable with current therapies. Cyclin-D1 has been postulated as an effective therapeutic target, but its evaluation has been hampered by our incomplete understanding of its oncogenic functions and by the lack of valid MCL murine models. To address these issues, we generated a cyclin-D1-driven mouse model whereby cyclin-D1 expression can be externally regulated. These mice developed lymphomas capable of recapitulating most features of human MCL. We found that cyclin-D1 inactivation was not sufficient to induce lymphoma regression in vivo. However, using a combination of in vitro and in vivo assays, we identified a novel pro-survival cyclin-D1 function in MCL cells. Specifically, we demonstrate that cyclin-D1 sequestrates the pro-apoptotic protein BAX, thereby favoring BCL2 anti-apoptotic function. Accordingly, cyclin-D1 inhibition sensitized the lymphoma cells to apoptosis through BAX release. Thus, genetic or pharmacologic targeting of cyclin-D1 combined with a pro-apoptotic BH3 mimetic synergistically killed murine lymphomas and human MCL cells. Our study identifies a novel role of cyclin-D1 in deregulating apoptosis and highlights the potential benefit of simultaneously targeting cyclin-D1 and survival pathways in patients with MCL.
A cyclin-D1 interaction with BAX underlies its oncogenic role and potential as a therapeutic target in mantle cell lymphoma.
Specimen part, Cell line
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High-throughput sequencing analysis of the chromosome 7q32 deletion reveals IRF5 as a potential tumour suppressor in splenic marginal-zone lymphoma.
Specimen part, Disease, Disease stage
View SamplesUsing high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Notably, deletion or uniparental disomy of chromosome 7q were detected in 39% of SMZLs but in only 9 of 170 (5%) mature B-cell lymphomas (p<10-6). The presence of unmutated IgVH genes, genomic complexity, 17p13-P53 deletion and 8q gain including MYC gene, but not 7q deletion, were correlated with shorter overall survival. Extensive mapping analyses narrowed down the commonly deleted region to 2.7 Mb. in 7q32.1-q32.2 from SND1 to COPG2 genes. High-throughput sequencing analysis of the 7q32 deleted segment in SMZL cells did not identify bi-allelic deletions, insertions or clear pathogenic mutations, but detected six single nucleotide changes in IRF5 (n=2), TMEM209 (n=2), CALU (n=1) and ZC3HC1 (n=1). Comparative expression analysis found that IRF5, TMEM209 and CALU genes had down-regulated expression in lymphomas with 7q32 deletion vs. non-deleted tumors. Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased cell proliferation and induced apoptosis. These results indicate that small deletions, insertions and/or point mutations inactivating genes within 7q32 are not common events in SMZL. Further studies are required to evaluate the putative role of IRF5 in SMZL pathogenesis.
High-throughput sequencing analysis of the chromosome 7q32 deletion reveals IRF5 as a potential tumour suppressor in splenic marginal-zone lymphoma.
Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.
Sex, Specimen part, Cell line
View SamplesHistone deacetylases (HDACs) have been identified as therapeutic targets due to regulatory function in DNA structure and organization. We have analyzed the role of the LBH589, a novel pan inhibitor of class I and II HDACs, in Acute Lymphoblastic Leukemia. In vitro, LBH589 was shown to induce a dose dependent antiproliferative and apoptotic effect which was associated with an increase in the acetylation of H3 and H4 histone acetylation which was uniformly in every genetic subgroup of ALL. In vivo administration of LBH589 in BALB/c-RAG2-/-c-/- mice in which T and B-cell leukemic cell lines were injected induced a significant reduction in tumor growth (TOM-1, p<0.01 and MOLT-4 p<0.05). Leukemic cells from patients were employed to establish a xenograft model of human leukemia in BALB/c-RAG2-/-c-/- mice and further transplanted in consecutive generations of mice. Treatment of these xenografts with LBH589 induced an increase in the acetylation of H3 and H4 and prolonged the survival of mice in comparison with the animals treated with Vincristine and Dexametasone (p<0.05) and this effect was significantly higher when LBH589 was combined with Vincristine and Dexametasone (p<0.001). Our results that the use of LBH589 in combination with standard chemotherapy represents an attractive option for treatment of patients with ALL.
Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.
Cell line
View SamplesGene expression analyis of primary MCL including IGHV mutated and unmutated cases
Molecular subsets of mantle cell lymphoma defined by the IGHV mutational status and SOX11 expression have distinct biologic and clinical features.
Specimen part, Disease, Disease stage
View Samplesp63 mutations have been associated with several human hereditary disorders characterized by ectodermal dysplasia such as EEC syndrome, ADULT syndrome and AEC syndrome . The location and functional effects of the mutations that underlie these syndromes reveal a striking genotype-phenotype correlation. Unlike EEC and ADULT that result from missense mutations in the DNA-binding domain of p63, AEC is solely caused by missense mutations in the SAM domain of p63. We report a study on the TAp63a isoform, the first to be expressed during development of the embryonic epithelia, and on its naturally occurring Q540L mutant derived from an AEC patient. To assess the effects of the Q540L mutation, we generated stable cell lines expressing TAp63a wt, DeltaNp63 alpha or the TAp63 alpha-Q540L mutant protein and used them to systematically compare the cell growth regulatory activity of the mutant and wt p63 proteins and to generate, by microarray analysis, a comprehensive profile of differential gene expression. We found that the Q540L substitution impairs the transcriptional activity of TAp63a and causes misregulation of genes involved in the control of cell growth and epidermal differentiation.
The Hay Wells syndrome-derived TAp63alphaQ540L mutant has impaired transcriptional and cell growth regulatory activity.
No sample metadata fields
View SamplesIn a pilot experiment to reprogramme MEF into endoderm, we infected MEF with the Yamanakas factors (O: Oct4, K: Klf4, S: Sox2, M:Myc), FoxA2 (F) and Gata4 (G). Global gene expression of isolated clones was performed.
Gata4 blocks somatic cell reprogramming by directly repressing Nanog.
No sample metadata fields
View SamplesAnti-retroviral therapy (ART) has transformed human immunodeficiency virus (HIV) infection from a fatal illness to a chronic condition by controlling viral replication and restoring immune function. However, chronic T-cell activation can be observed in 20-35% of individuals on ART, resulting in an immune reconstitution inflammatory syndrome (IRIS) [1-3]. IRIS involving the CNS can result in permanent disability and death [4]. Tat is a viral protein produced in HIV-infected cells and released into the extracellular space [5]. We show that the secreted-Tat protein activated uninfected T-cells in an antigen-independent manner without inducing proliferation. Notably, Tat induced the secretion of IL-17 from T-cells and increased the percentage of T-cells with a Th17 phenotype. T-cell activation was independent of the T-cell receptor but dependent on endocytosis of Tat and activation of vascular endothelial growth factor receptor 2 (VEGFR2). Tat induced global changes in histone acetylation and increased HIV infection in non-replicating T-cells. Furthermore, in an individual with CNS IRIS, Tat expressing infiltrates and secretion of IL-17 was detected in the absence of viral replication in the brain. Thus Tat can induce T-cell activation in a paracrine and autocrine manner resulting in propagation of inflammation and increased virulence.
Induction of IL-17 and nonclassical T-cell activation by HIV-Tat protein.
Specimen part, Treatment, Time
View SamplesWe treated intestinal enteroids continuously for 6 days with or without TgfbR1/2 inhibitor (LY2109761) or Tgfb1 ligand
Single cell lineage tracing reveals a role for TgfβR2 in intestinal stem cell dynamics and differentiation.
Specimen part
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