The clinical course of patients with chronic lymphocytic leukemia (CLL) is heterogeneous. Several prognostic factors have been identified that can stratify patients into groups that differ in their relative tendency for disease progression and/or survival. Here, we pursued a subnetwork-based analysis of gene expression profiles to discriminate between groups of patients with disparate risks for CLL progression.
Subnetwork-based analysis of chronic lymphocytic leukemia identifies pathways that associate with disease progression.
Specimen part
View SamplesWe examined the microRNAs (miRNAs) expressed in chronic lymphocytic leukemia (CLL) and identified miR-150 as the most abundant, but with leukemia-cell-expression levels that varied among patients. CLL cells that expressed ZAP-70 or that used unmutated IGHV each had a median expression-level of miR-150 that was significantly lower than that of ZAP-70-negative CLL cells or those that used mutated IGHV. In samples stratified for expression of miR-150, CLL cells with low-level miR-150 expressed relatively higher levels of forkhead box P1 (FOXP1) and GRB2-associated binding protein 1 (GAB1), genes with 3 UTRs having evolutionary-conserved binding sites for miR-150. High-level expression of miR-150 could repress expression of these genes, which encode proteins that may enhance B-cell receptor (BCR) signaling, a putative CLL-growth/survival signal. Also, high-level expression of miR-150 levels was a significant independent predictor of longer treatment-free-survival (TFS) or overall survival (OS), whereas an inverse association was observed for high-level expression of GAB1 or FOXP1 for OS. This study demonstrates that expression of miR-150 can influence the relative expression of GAB1 and FOXP1 and the signaling potential of the B-cell receptor (BCR), thereby possibly accounting for the noted association of expression of miR-150 and disease outcome.
miR-150 influences B-cell receptor signaling in chronic lymphocytic leukemia by regulating expression of GAB1 and FOXP1.
Specimen part, Disease stage
View SamplesIGHV mutation status is a well-established prognostic factor in chronic lymphocytic leukemia, and also provides crucial insights into tumor cell biology and function. Currently, determination of IGHV transcript sequence, from which mutation status is calculated, requires a specialized laboratory procedure. RNA sequencing is a method that provides high resolution, high dynamic range transcriptome data that can be used for differential expression, isoform discovery, and variant determination. In this paper, we demonstrate that unselected next-generation RNA sequencing can accurately determine the IGH@ sequence, including the complete sequence of the complementarity-determining region 3 (CDR3), and mutation status of CLL cells, potentially replacing the current method which is a specialized, single-purpose Sanger-sequencing based test. Overall design: CLL cells were sequenced by mRNA-seq on the Illumina platform then subjected to the costom bioinformatic pipeline Ig-ID which yields IGH data
Immunoglobulin transcript sequence and somatic hypermutation computation from unselected RNA-seq reads in chronic lymphocytic leukemia.
No sample metadata fields
View SamplesWe used the microarrays to obtain the cancerous signatures of T-cell, B-cell, erythroid and megakaryoblastic leukemias in mice.
Gene profiling of the erythro- and megakaryoblastic leukaemias induced by the Graffi murine retrovirus.
No sample metadata fields
View SamplesTDP-43 is an RNA/DNA-binding protein implicated in transcriptional repression and mRNA processing. Inclusions of TDP-43 are hallmarks of frontotemporal dementias and amyotrophic lateral sclerosis. Besides aggregation of TDP-43, loss of nuclear localization is observed in disease. To identify relevant targets of TDP-43, we performed an expression profiling study. Thereby, histone deacetylase 6 (HDAC6) downregulation was discovered upon TDP-43 silencing on mRNA and protein level in human embryonic kidney HEK293E and neuronal SH-SY5Y cells. This was accompanied by accumulation of the major HDAC6 substrate, acetyl-tubulin. Expression of wild-type but neither RNA-binding- nor nuclear-localization-deficient TDP-43 restored HDAC6 expression. Moreover, TDP-43 bound specifically to HDAC6 mRNA arguing for a direct functional interaction. Importantly, in vivo validation in TDP-43 knockout Drosophila melanogaster also showed HDAC6 mRNA decrease. HDAC6 is necessary for protein aggregate formation and degradation. Indeed, downregulation of HDAC6 reduced aggregate formation and increased cytotoxicity of expanded poly-glutamine ataxin-3 in TDP-43 silenced cells. This was completely restored by co-transfection with HDAC6. In conclusion, loss of functional TDP-43 causes HDAC6 downregulation and might thereby contribute to pathogenesis.
Knockdown of transactive response DNA-binding protein (TDP-43) downregulates histone deacetylase 6.
Cell line
View SamplesThe lipocalin Apolipoprotein D (ApoD), known to protect the nervous system against oxidative stress (OS) in model organisms, is up-regulated early in the mouse brain in response to the ROS generator paraquat (PQ). However, the processes triggered by this up-regulation have not been explored.
Apolipoprotein D alters the early transcriptional response to oxidative stress in the adult cerebellum.
Sex, Specimen part
View SamplesIn the adult mammalian testis, spermatogenic differentiation starts from a minute population of spermatogonial stem cells (SSCs). SSCs are generated after birth from the fetal gonocytes, themselves derived from the primordial germ cells (PGCs), which are specified during the first days after implantation. Transcriptome profiling of purified preparations evidenced the preferential accumulation in SSCs of transcripts of PU.1 (Sfpi1), a regulatory gene previously identified in hematopoietic progenitors. In situ immunolabeling and RNA determination showed a complex pattern of expression in the adult testis, first in SSCs and early spermatogonia followed by de novo expression in pachytene spermatocytes.
PU.1 (Sfpi1), a pleiotropic regulator expressed from the first embryonic stages with a crucial function in germinal progenitors.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An international standardization programme towards the application of gene expression profiling in routine leukaemia diagnostics: the Microarray Innovations in LEukemia study prephase.
No sample metadata fields
View SamplesAn International Multi-Center Study to Define the Clinical Utility of MicroarrayBased Gene Expression Profiling in the Diagnosis and Sub-classification of Leukemia (MILE Study)
An international standardization programme towards the application of gene expression profiling in routine leukaemia diagnostics: the Microarray Innovations in LEukemia study prephase.
Disease
View SamplesAn international standardization program towards the application of gene expression profiling in routine leukaemia diagnostics: The MILE study pre-phase.
An international standardization programme towards the application of gene expression profiling in routine leukaemia diagnostics: the Microarray Innovations in LEukemia study prephase.
No sample metadata fields
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