Acquired imatinib resistance in chronic myelogenous leukemia (CML) can be the consequence of mutations in the kinase domain of BCR-ABL or increased protein levels. However, as in other malignancies, acquired resistance to cytostatic drugs is a common reason for treatment failure or disease progression. As a model for drug resistance, we developed a CML cell line resistant to cyclophosphamide (CP). Using oligonucleotide arrays, we examined changes in global gene expression. Selected genes were also examined by real-time PCR and flow cytometry. Neither the parent nor the resistant lines had mutations in their ATP binding domain. Filtering genes with a low-base line expression, a total of 239 genes showed significant changes (162 up- and 77 down-regulated) in the resistant clone. Most of the up-regulated genes were associated with metabolism, signal transduction, or encoded enzymes. The gene for aldehyde dehydrogenase 1 was over-expressed more than 2000 fold in the resistant clone. BCR-ABL was expressed in both cell lines to a comparable extent. When exposed to the tyrosine kinase inhibitors imatinib and nilotinib, both lines were sensitive. In conclusion, we found multiple genetic changes in a CML cell line resistant to CP related to metabolism, signal transduction or apoptosis. Despite these changes, the resistant cells retained sensitivity to tyrosine kinase inhibitors.
Comparative gene expression analysis of a chronic myelogenous leukemia cell line resistant to cyclophosphamide using oligonucleotide arrays and response to tyrosine kinase inhibitors.
No sample metadata fields
View SamplesIn order to characterize defense responses not only cytologically, but also on the transcript level, genome-wide sequencing of mRNA isolated from non-infected control leaves and from leaves inoculated either with the WT or with GLS1 overexpressing strains was performed, using Illumina Next Generation Sequencing Technology. In order to identify transcripts specifically induced in leaves infected by ß-1,3-glucan-exposing strains, transcript patterns of leaves inoculated with GLS1 overexpressing PtrpC:GLS1 strains were compared with those of the WT. In PtrpC:GLS1-inoculated leaves, a total of 2179 genes were more than 2.5-fold increased, with many genes known as genes typically up-regulated in PAMP-triggered defense responses. These genes include genes encoding PR proteins enzymes involved in cell wall re-inforcemen, and terpene synthases possibly involved in phytoalexin synthesis. Furthermore, increased transcript abundance of genes encoding serine-threonine receptor-like kinases calmodulin, as well as zinc-finger and WRKY transcription factors have been identified. Other up-regulated genes encode proteins involved in protein degradation, i.e. proteases, ubiquitin ligases, as well as enzymes involved in synthesis of auxin or cytokinin phytohormones. In comparison, 2164 genes were more than 2.5-fold down-regulated in maize leaves infected by PtrpC:GLS1 strains, as compared to WT-infected leaves. Several of the encoded proteins are known susceptibility factors. Forty-six down-regulated genes code for proteins containing iron or manganese, or are involved in uptake of these ions, suggesting major re-arrangement of the redox-status in maize leaves after ß-glucan perception. Overall design: Examination of plant defense responses in maize plants inoculated with 2 different Colletotrichum graminicola strains.
Infection structure-specific expression of β-1,3-glucan synthase is essential for pathogenicity of Colletotrichum graminicola and evasion of β-glucan-triggered immunity in maize.
Age, Subject, Time
View SamplesWe analyzed expression changes between JAK2V617F positive bone marrow cells and JAK2V617F negative cells
Autocrine Tnf signaling favors malignant cells in myelofibrosis in a Tnfr2-dependent fashion.
Specimen part, Treatment
View SamplesThis is a class prediction experiment, where the class is the response status to imatinib (also called Gleevec), a drug used to treat patients with chronic myelogenous leukemia (CML). There are two data sets, a training set (from Leipzig, 8 Responders and 5 Non-Responders) and a validation set (from Mannheim, 8 Responders and 7 Non-Responders). The objective is to identify differentially regulated genes between CML patients who respond and those who do not respond to imatinib and confirm the results in the validation data set. The samples from blood or bone marrow of CML patients were hybridized to Affymetrix HG-U95Av2 chip and RMA was used to generate the normalized signal values.
In chronic myeloid leukemia white cells from cytogenetic responders and non-responders to imatinib have very similar gene expression signatures.
No sample metadata fields
View SamplesThe miR-155-dependent differences in gene expression in the HSPC compartment of FLT3-ITD mice is unknown. In this experiment, we performed RNA sequencing on FLT3-ITD and FLT3-ITD miR-155-/- mouse LKS cells. Overall design: RNA sequencing was performed on RNA extracted from Lin-, cKit+, Sca1+ cells isolated via flow cytometry from FLT3-ITD and FLT3-ITD miR-155-/- mice. 3 samples were submitted for sequencing for each experimental group. Each sample contains RNA from 3 mice, in order to get enough RNA from this rare stem cell population.
miR-155 promotes FLT3-ITD-induced myeloproliferative disease through inhibition of the interferon response.
Specimen part, Subject
View SamplesBackground: In multiple sclerosis (MS), immune up-regulation is coupled to subnormal immune response to interferon-β (IFN-β) and low serum IFN-β levels. The relationship between the defect in IFN signalling and acute and long-term effects of IFN-β on gene expression in MS is inadequately understood. Methods: We profiled IFN-β-induced transcriptome shifts, using high-resolution microarrays on 227 mononuclear cell samples from IFN-β-treated MS Complete Responders (CR) stable for five years, and stable and active Partial Responders (PR), stable and active untreated MS, and healthy controls. Findings: IFN-β injection induced short-term changes in 1,200 genes compared to baseline expression after 4-day IFN washout. Pre-injection after washout, and in response to IFN-β injections, PR more frequently had abnormal gene expression than CR. Surprisingly, short-term IFN-β induced little shift in Th1/Th17/Th2 gene expression, but up-regulated immune-inhibitory genes (ILT, IDO1, PD-L1). Expression of 8,800 genes was dysregulated n therapy-naïve compared to IFN-β-treated patients. These long-term changes in protein-coding and long non-coding RNAs affect immunity, synaptic transmission, and CNS cell survival, and correct the disordered therapy-naïve transcriptome to near-normal. In keeping with its impact on clinical course and brain repair in MS, long-term IFN-β treatment reversed the overexpression of proinflammatory and MMP genes, while enhancing genes involved in the oligodendroglia-protective integrated stress response, neuroprotection, and immunoregulation. In the rectified long-term signature, 277 transcripts differed between stable PR and CR patients.
Interferon-β corrects massive gene dysregulation in multiple sclerosis: Short-term and long-term effects on immune regulation and neuroprotection.
Age, Specimen part
View SamplesNewly diagnosed chronic phase chronic myeloid leukemia (CML) patients with a major cytogenetic response (MCyR) after 12 months of imatinib therapy have an excellent long-term outcome, while patients without MCyR have a high progression risk. Since patients with primary cytogenetic resistance may benefit from more intensive therapy up-front, we sought to identify biomarkers to predict MCyR.
A gene expression signature of CD34+ cells to predict major cytogenetic response in chronic-phase chronic myeloid leukemia patients treated with imatinib.
No sample metadata fields
View SamplesCoordinated BCR-ABL1 kinase-dependent and -independent mechanisms convert p27 from a nuclear tumor suppressor to a cytoplasmic oncogene. Persistence of oncogenic p27 functions despite effective inhibition of BCR-ABL1 may contribute to resistance to tyrosine kinase inhibitors. Overall design: BCR-ABL1 induced p27 versus knockout, controlling with Empty vector p27 versus knock out
BCR-ABL1 promotes leukemia by converting p27 into a cytoplasmic oncoprotein.
No sample metadata fields
View SamplesMYC is induced early in human adipose stem cells in response to a standard MDIR adipogenic cocktail. The objective of this experiment was to identify key gene networks impacted by MYC loss-of-function in a mixed donor pool of human derived adipose stem cells.
MYC is an early response regulator of human adipogenesis in adipose stem cells.
Sex, Race
View SamplesProjection-dependent ribosome profling from mouse mPFC.
Molecular and Circuit-Dynamical Identification of Top-Down Neural Mechanisms for Restraint of Reward Seeking.
Specimen part
View Samples