Previous studies in our laboratory demonstrated that the azurophil granule protease neutrophil elastase (NE) cleaves PML-RARA (PR), the fusion protein that initiates acute promyelocytic leukemia (APL). Further, NE deficiency reduces the penetrance of APL in a murine model of this disease. We therefore predicted that NE-mediated PR cleavage might be important for its ability to initiate APL. To test this hypothesis, we generated a mouse expressing NE-resistant PR. These mice developed APL indistinguishable from wild type PR, but with significantly reduced latency (median leukemia-free survival of 274 days versus 473 days for wild type PR, p<0.001). Resistance to proteolysis may increase the abundance of full length PR protein in early myeloid cells, and our previous data suggested that non-cleaved PR may be less toxic to early myeloid cells. Together, these effects appear to increase the leukemogenicity of NE-resistant PR, contrary to our previous prediction. We conclude that NE deficiency may reduce APL penetrance via indirect mechanisms that are still NE dependent.
A protease-resistant PML-RAR{alpha} has increased leukemogenic potential in a murine model of acute promyelocytic leukemia.
Cell line
View SamplesTo better understand the pathogenesis of acute promyelocytic leukemia (APL, FAB M3 AML), we identified genes that are expressed differently in APL cells compared to other acute myeloid leukemia subtypes, and to normal promyelocytes. Comparative gene expression analysis of 14 M3, 62 other AML (M0, M1, M2 and M4) and 5 enriched normal promyelocyte samples revealed a signature of 1,121 genes that are specifically dysregulated in M3 samples relative to other AML, and that do not simply represent normal promyelocyte expression (M3-specific signature). We used a novel, high throughput digital platform (Nanostring's nCounter system) to evaluate a subset of the most significantly dysregulated genes in 30 AML samples; 33 of 37 evaluable gene expression patterns were validated. In an additional analysis, we selected only genes that are dysregulated in M3 both compared to other AML subtypes, and to purified normal CD34+ cells, promyelocytes, and/or neutrophils, thereby isolating a 478 gene "composite M3 dysregulome". Surprisingly, the expression of only a few of these genes was significantly altered in PR-9 cells after PML-RARA induction, suggesting that most of these genes are not direct targets of PML-RARA. Comparison of the M3-specific signature to our previously described murine APL dysregulome revealed 33 commonly dysregulated genes, including JUN, EGR1, and TNF. Collectively, these results suggest that PML-RARA initiates a transcriptional cascade which generates a unique downstream expression signature in both primary human and mouse APL cells.
High throughput digital quantification of mRNA abundance in primary human acute myeloid leukemia samples.
Sex, Race
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Distinct Gene Regulatory Pathways for Human Innate versus Adaptive Lymphoid Cells.
Specimen part
View SamplesInnate lymphoid cells (ILCs) serve as sentinels in mucosal tissues, sensing release of soluble inflammatory mediators, rapidly communicating danger via cytokine secretion, and functioning as guardians of tissue homeostasis. Although ILCs have been studied extensively in model organisms, little is known about these first responders in humans, especially their lineage and functional kinships to cytokine-secreting T helper cell (Th) counterparts. Here, we report gene regulatory circuitries for four human ILCTh counterparts derived from mucosal environments, revealing that each ILC subset diverges as a distinct lineage from Th and circulating natural killer cells, but shares circuitry devoted to functional polarization with their Th counterparts. Super-enhancers demarcate cohorts of cell identity genes in each lineage, uncovering new modes of regulation for signature cytokines, novel molecules that likely impart important functions to ILCs, and potential mechanisms for autoimmune disease SNP associations within ILCTh subsets.
Distinct Gene Regulatory Pathways for Human Innate versus Adaptive Lymphoid Cells.
Specimen part
View SamplesMost B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation. Overall design: Expression profiles of follicular lymphoma, centrocyte and peripheral blood B cells were generated by deep sequencing, using Illumina Hi-Seq 2000.
NKG2D-NKG2D Ligand Interaction Inhibits the Outgrowth of Naturally Arising Low-Grade B Cell Lymphoma In Vivo.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Enhancer sequence variants and transcription-factor deregulation synergize to construct pathogenic regulatory circuits in B-cell lymphoma.
Sex, Age, Specimen part
View SamplesMost B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation.
Enhancer sequence variants and transcription-factor deregulation synergize to construct pathogenic regulatory circuits in B-cell lymphoma.
Sex, Age, Specimen part
View SamplesTo identify signature genes that help distinguish (1) sepsis from non-infectious causes of systemic inflammatory response syndrome, (2) between Gram-positive and Gram-negative sepsis.
Gene-expression profiling of peripheral blood mononuclear cells in sepsis.
No sample metadata fields
View SamplesActivating mutations in tyrosine kinase (TK) genes (e.g. FLT3 and KIT) are found in more than 30% of patients with de novo acute myeloid leukemia (AML); many groups have speculated that mutations in other TK genes may be present in the remaining 70%. We performed high-throughput re-sequencing of the kinase domains of 26 TK genes (11 receptor TK and 15 cytoplasmic TK) that are expressed in most AML patients, using genomic DNA from the bone marrow (tumor) and matched skin biopsy samples (germline) from 94 patients with de novo AML; sequence variants were validated in an additional 94 AML tumor samples (14.3 million base pairs of sequence were obtained and analyzed). We identified known somatic mutations in FLT3, KIT, and JAK2 TK genes at the expected frequencies, and found four novel somatic mutations, JAK1V623A, JAK1T478S, DDR1A803V and NTRK1S677N, once each in four respective patients out of 188 tested. We also identified novel germline sequence changes encoding amino acid substitutions (i.e. non-synonymous changes) in 14 TK genes, including TYK2, which had the largest number of non-synonymous sequence variants (11 total detected). Additional studies will be required to define the roles that these somatic and germline TK gene variants play in AML pathogenesis.
Somatic mutations and germline sequence variants in the expressed tyrosine kinase genes of patients with de novo acute myeloid leukemia.
Sex, Age, Specimen part, Race
View SamplesOsteoarthritis (OA) is a degenerative joint disease that involves destruction of articular cartilage and eventually leads to disability. Mesenchymal stem cells (MSCs) reside in healthy and diseased cartilage, and through their chondrogenic potential may provide a strategy for cartilage repair. To this end, we performed an image-based, high throughput screen and identified the small molecule, kartogenin, that promotes selective MSC differentiation into chondrocytes (EC50=100nM), shows chondroprotective effects in vitro, and is efficacious in two OA animal models. Kartogenin binds filamin A and induces chondrogenesis by regulating the CBFbeta-RUNX1 transcriptional program. This work provides new insights into the control of chondrogenesis that may ultimately lead to an effective stem-cell based therapy for osteoarthritis.
A stem cell-based approach to cartilage repair.
Specimen part
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