Dysregulation of different classes of tRNA fragments in chronic lymphocytic leukemia
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE138889 | GEO | 2019/11/11
REPOSITORIES: GEO
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Project description:B cell chronic lymphocytic leukemia (CLL) is often preceded by a benign monoclonal or oligoclonal CD5+ B cell lymphocytosis. We have generated transgenic mice expressing a catalytically inactive, dominant-negative recombination activating gene 1 (dnRAG1 mice) in the periphery. These animals develop an early-onset indolent CD5+ B cell lymphocytosis, caused in part by a defect in secondary V(D)J rearrangements initiated to alter autoreactive B cell receptor specificity. Hypothesizing that the CD5+ B cells accumulating in dnRAG1 mice represent a CLL precursor, we crossed dnRAG1 mice with CLL-prone Eµ-TCL1 mice to determine whether dnRAG1 expression in Eµ-TCL1 mice accelerates the onset of CLL-like disease. We find that CD5+ B cell expansion and CLL progression occurs more rapidly and uniformly in double-transgenic mice (DTG mice) compared to Eµ-TCL1 mice, but with similar phenotypic and leukemogenic features. To gain insight into genes or pathways responsible for CD5+ B cell accumulation in the transgenic mice, we performed comparative gene expression profiling studies using normal and CD5+ B cells isolated from wild-type and transgenic mice at either 12 weeks of age (pre-leukemia) or at CLL onset in DTG mice (using age-matched wild-type and single-transgenic mice as controls). These analyses confirm the upregulation of tolerogenic genes in CD5+ B cells and reveal a possible role for prolactin signaling in the regulation of receptor editing. This study suggests that a failure to remodel B cell antigen receptor genes in response to autoreactivity may promote the benign accumulation of CD5+ B cells, which may then be subjected to secondary genetic lesions that promote CLL progression. dnRAG1 mice were bred to Eµ-TCL1 mice to obtain cohorts of wild-type (WT), single-transgenic (dnRAG1 and Eµ-TCL1), and DTG mice. Splenic CD19+B220hiCD5- B cells from WT mice or CD19+CD5+ B cells from transgenic mice were purified using fluorescence activated cell sorting (FACS). Biotin end-labeled cDNA prepared from the sorted cells was hybridized to Mouse Gene 1.0 ST Arrays. These experiments were performed two independent times: once with a cohort of 12-week-old mice, and once with older mice (>34 weeks old) consisting of two ill DTG mice and their age-matched counterparts. At least two biological replicates were used where possible.
2013-06-04 | E-GEOD-44940 | biostudies-arrayexpress
Project description:Analysis of Hoechst dye 33342-effluxing side population (SP) cells from B-CLL peripheral blood mononuclear cells. 9 biological replicates from B-CLL patients sorted into CD5+CD19+ SP and non-SP subsets. Two color comparative gene expression using Agilent microarrays.
2011-09-26 | E-GEOD-30171 | biostudies-arrayexpress
Project description:B cell chronic lymphocytic leukemia (CLL) is often preceded by a benign monoclonal or oligoclonal CD5+ B cell lymphocytosis. We have generated transgenic mice expressing a catalytically inactive, dominant-negative recombination activating gene 1 (dnRAG1 mice) in the periphery. These animals develop an early-onset indolent CD5+ B cell lymphocytosis, caused in part by a defect in secondary V(D)J rearrangements initiated to alter autoreactive B cell receptor specificity. Hypothesizing that the CD5+ B cells accumulating in dnRAG1 mice represent a CLL precursor, we crossed dnRAG1 mice with CLL-prone Eµ-TCL1 mice to determine whether dnRAG1 expression in Eµ-TCL1 mice accelerates the onset of CLL-like disease. We find that CD5+ B cell expansion and CLL progression occurs more rapidly and uniformly in double-transgenic mice (DTG mice) compared to Eµ-TCL1 mice, but with similar phenotypic and leukemogenic features. To gain insight into genes or pathways responsible for CD5+ B cell accumulation in the transgenic mice, we performed comparative gene expression profiling studies using normal and CD5+ B cells isolated from wild-type and transgenic mice at either 12 weeks of age (pre-leukemia) or at CLL onset in DTG mice (using age-matched wild-type and single-transgenic mice as controls). These analyses confirm the upregulation of tolerogenic genes in CD5+ B cells and reveal a possible role for prolactin signaling in the regulation of receptor editing. This study suggests that a failure to remodel B cell antigen receptor genes in response to autoreactivity may promote the benign accumulation of CD5+ B cells, which may then be subjected to secondary genetic lesions that promote CLL progression.
2013-06-04 | GSE44940 | GEO
Project description:Chronic lymphocytic leukemia (CLL) is one of the most diagnosed forms of leukemia worldwide and it is usually classified into two forms: indolent and aggressive. These two forms are characterized by distinct molecular features that drive different responses to treatment and clinical outcomes. In this context, a better understanding of the molecular landscape of the CLL forms may potentially lead to the development of new drugs or the identification of novel biomarkers. Human Endogenous Retroviruses (HERVs) are a class of transposable elements that have been associated with the development of different human cancers, including different forms of leukemias. However, no studies about HERVs in CLL have ever been reported so far. Here, we present the first locus-specific profiling of HERV expression in both the aggressive and indolent forms of CLL. Our analyses revealed several dysregulations in HERV expression occurring in CLL and some of them were specific for either the aggressive or indolent form of CLL. Such results were also validated by analyzing an external cohort of CLL patients and by RT-qPCR. Moreover, in-silico analyses have shown relevant signaling pathways associated with them suggesting a potential involvement of the dysregulated HERVs in these pathways and consequently in CLL development.
2024-04-17 | GSE233157 | GEO
Project description:The cellular origin of chronic lymphocytic leukemia (CLL) is debated. Transcriptome analysis of CLL and normal peripheral blood and splenic B cell subsets displayed highest similarity of CLL to mature CD5+ B cells. We identified a distinct CD5+CD27+ post-germinal center B cell subset, and revealed that immunoglobulin V gene mutated CLL are more similar to mutated CD5+ B cells, whereas unmutated CLL are more related to unmutated CD5+ B cells. Stereotyped immunoglobulin V gene rearrangements were significantly enriched among CD5+ B cells, providing further genetic evidence for a derivation of CLL from CD5+ B cells. Moreover, we identified deregulated expression patterns providing novel insights into the pathophysiology of CLL, including downregulation of EBF1 and KLF family members. Transcriptome profiling of CLL and healthy human blood and splenic mature B cell subsets. Identification of deregulated transcription patterns with implications on CLL pathobiology.
2012-09-27 | GSE36907 | GEO
Project description:The cellular origin of chronic lymphocytic leukemia (CLL) is debated. Transcriptome analysis of CLL and normal peripheral blood and splenic B cell subsets displayed highest similarity of CLL to mature CD5+ B cells. We identified a distinct CD5+CD27+ post-germinal center B cell subset, and revealed that immunoglobulin V gene mutated CLL are more similar to mutated CD5+ B cells, whereas unmutated CLL are more related to unmutated CD5+ B cells. Stereotyped immunoglobulin V gene rearrangements were significantly enriched among CD5+ B cells, providing further genetic evidence for a derivation of CLL from CD5+ B cells. Moreover, we identified deregulated expression patterns providing novel insights into the pathophysiology of CLL, including downregulation of EBF1 and KLF family members. Transcriptome profiling of CLL and healthy human blood and splenic mature B cell subsets. Identification of deregulated transcription patterns with implications on CLL pathobiology. Human mature B cell subsets and CLL with mutated (mCLL) and unmutated V gene status (uCLL) were purified from peripheral blood and spleen. Samples of 5 to 7 donors each were collected and processed in three batches in a two rounded in vitro transcription protocol. Retrieved data were batch corrected and subjected to analysis. Human mature CD5+ B cell subsets and CLL with mutated (mCLL) and unmutated V gene status (uCLL) were purified from peripheral blood.
2012-09-27 | E-GEOD-36907 | biostudies-arrayexpress
Project description:Chronic Lymphocytic Leukaemia (CLL) is the most common leukemia in adults in the Western world. B cell receptor (BCR) signalling is known to be crucial for the pathogenesis and maintenance of CLL cells develop from mature CD5+ B cells. BCR signalling is regulated by the inhibitory co-receptor Siglec-G and Siglec-G-deficient mice have an enlarged CD5+ B1a cell population. Here, we determine how Siglec-G expression influences the severity of CLL.
2023-05-03 | GSE227678 | GEO
Project description:B-cell chronic lymphocytic leukemia (CLL) is a common type of leukemia, characterized by the progressive accumulation of CD5+ “mature” monoclonal B lymphocytes in peripheral blood, bone marrow and lymphoid tissues. Although circulating CLL cells are non-dividing cells, prone to spontaneous apoptosis, their progressive accumulation is the result of a dynamic balance between cell death and proliferation and a high turn-over rate has been related to a poor prognosis. Indeed, CLL cells are protected from apoptosis and proliferate in specific niches within the lymphoid tissues and the bone marrow. By gene-expression profiling we found out that IL-21 modulates the expression of several genes including cytokine and chemokine genes and genes involved in cell survival and apoptosis in CD40-activated CLL cells. To gain information of the possible mechanisms involved in the regulation of these genes we tested the possibility that IL-21 may act through specific miRNA regulation. PBMCs were isolated from heparinized blood obtained from 13 untreated patients diagnosed with CLL on the basis of clinical and immunophenotypic criteria. PBMCs were isolated by Ficoll density gradient centrifugation and characterized by immunofluorescence and FACS analysis. When residual non B-cells exceeded 10%, B cells were enriched by negative selection with antibody-coated magnetic beads (CD2-beads, Dynal, Oslo, Norway) to obtain a >95% pure CD19+/CD5+ B cell population. B-CLL cells were pre-activated on adherent CD40L-transduced L cells for 48-36h and then stimulated with IL-21 or medium only for additional 18h. Total RNA was isolated from samples using TriZol (Invitrogen) reagent. This Series represents 9 of the 13 cases.
2013-09-01 | E-GEOD-42160 | biostudies-arrayexpress
Project description:B-cell chronic lymphocytic leukemia (CLL) is a common type of leukemia, characterized by the progressive accumulation of CD5+ “mature” monoclonal B lymphocytes in peripheral blood, bone marrow and lymphoid tissues. Although circulating CLL cells are non-dividing cells, prone to spontaneous apoptosis, their progressive accumulation is the result of a dynamic balance between cell death and proliferation and a high turn-over rate has been related to a poor prognosis. Indeed, CLL cells are protected from apoptosis and proliferate in specific niches within the lymphoid tissues and the bone marrow. CLL cells show variable expression of IL-21R that can be up-regulated by cell activation via CD40. CD40-activated CLL cells phosphorylate STAT-1 and STAT-3 and undergo apoptosis in response to IL-21 stimulation. By gene-expression profiling we found out that IL-21 modulates the expression of several genes including cytokine and chemokine genes and genes involved in cell survival and apoptosis in CD40-activated CLL cells. PBMCs were isolated from heparinized blood obtained from 13 untreated patients diagnosed with CLL on the basis of clinical and immunophenotypic criteria. PBMCs were isolated by Ficoll density gradient centrifugation and characterized by immunofluorescence and FACS analysis. When residual non B-cells exceeded 10%, B cells were enriched by negative selection with antibody-coated magnetic beads (CD2-beads, Dynal, Oslo, Norway) to obtain a >95% pure CD19+/CD5+ B cell population. B-CLL cells were pre-activated on adherent CD40L-transduced L cells for 48-36h and then stimulated with IL-21 or medium only for additional 18h. Total RNA was isolated from samples using TriZol (Invitrogen) reagent.
2013-09-01 | E-GEOD-42158 | biostudies-arrayexpress
Project description:This work shows that signaling-lymphocytic-activation-molecule-1 (SLAMF1), a co-stimulatory molecule and a microbial sensor, is expressed by normal CD19+/CD5+ B-lymphocytes. Its expression is lost in a subset of patients with chronic lymphocytic leukemia (CLL) characterized by an aggressive form of the disease, with shorter time to first treatment and overall survival. Silencing of SLAMF1 in the CLL-like Mec-1 cell line (constitutively SLAMF1+) modulated pathways connected to cell migration, cytoskeletal organization and intracellular vesicle formation/recirculation. Loss of SLAMF1 was associated to increased expression of CXCR4, CD38 and CD44, positively affecting chemotactic responses to CXCL12. Ligation of SLAMF1 with an agonistic monoclonal antibody promoted the autophagic flux, by increasing reactive oxygen species (ROS) accumulation and inducing phosphorylation of p38, JNK1/2 and bcl-2. The direct consequence was the assembly of the autophagy macro-complex that included SLAMF1, the scaffold protein Beclin1 and the enzyme Vps34. Consistently, SLAMF1-silenced cells or SLAMF1low primary CLL cells were resistant to autophagy-activating therapeutic agents, such as fludarabine or the BH3 mimetic ABT-737. These results indicate that loss of SLAMF1 expression modulates genetic pathways regulating chemotaxis and autophagy and potentially affecting drug responses, thus providing a likely explanation for the unfavorable clinical outcome experienced by this patient subset.
2015-05-23 | GSE69165 | GEO