Epigenetic mechanisms contribute to deregulated gene expression of hematopoietic progenitors in Myelodysplastic Syndromes (MDS). Hypomethylating agents are able to improve peripheral cytopenias in MDS patients. To identify critical gene expression changes induced by hypomethylating agents, we analyzed gene expression profiling (GEP) of myelodysplastic and normal CD34+ hematopoietic stem cells treated in vitro with or without decitabine. Four MDS and two untreated early stage Hodgkins lymphomas were analyzed for GEP. Mock treated CD34+ stem cells segregate according to diagnosis and karyotype. After decitabine treatment, gene expression changes were more consistent on MDS CD34+ cells with abnormal kayotype. Comparing decitabine-induced genes with those found down-regulated in mock-treated MDS cells, we identified a list of candidate tumor suppressor genes in MDS. By real-time RT-PCR we confirmed expression changes for three selected genes CD9, CXCR4 and GATA2 in 12 MDS patients and 4 controls. CD9 was widely repressed in most MDS CD34+ cell samples, although similar levels of methylation were found in both normal and MDS total bone marrows. CXCR4 promoter methylation was absent in total bone marrows from 36 MDS patients. In conclusion, changes in gene expression changes induced by hypomethylating treatment are more pronounced in CD34+ cells from abnormal karyotype.
Gene expression profiling of myelodysplastic CD34+ hematopoietic stem cells treated in vitro with decitabine.
Sex, Age, Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Muscle Expression of SOD1(G93A) Modulates microRNA and mRNA Transcription Pattern Associated with the Myelination Process in the Spinal Cord of Transgenic Mice.
Age, Specimen part
View SamplesEpigenetic changes play a role in the pathogenesis of myeloid malignancies and hypomethylating agents have shown efficacy in these diseases. We studied the apoptotic effect, the genome-wide methylation and gene expression profiles in HL60 cells following decitabine treatment, using micro-array technologies. Decitabine treatment resulted in a decrease in global DNA methylation, corresponding to 4876 probeset IDs with significantly reduced methylation levels, while expression of 2583 IDs was induced. The integrated analysis identified 160 genes demethylated and upregulated by decitabine, mainly including development and differentiation pathways genes. Genes target of polycomb group protein regulation were overrepresented in this group. Apoptosis was induced by decitabine and apoptosis-specific PCR arrays more precisely indicated decitabine-induced upregulation of 13 apoptosis-related genes, in particular Dap-kinase 1 and Bcl2L10. Correspondingly, in primary patient samples, BCL2L10 was hypermethylated in 45% of AML, 43% of therapy-related myeloid neoplasms, 12% of MDS and in none of the controls.
Analysis of genome-wide methylation and gene expression induced by 5-aza-2'-deoxycytidine identifies BCL2L10 as a frequent methylation target in acute myeloid leukemia.
Specimen part
View SamplesExpression profiling of lumbar spinal cord from MLC/SOD1G93A mice and age matched controls at 120 days of age. We used Affymetrix GeneChip Mouse Gene expression 2.0 st Array to determine differential gene expression.
No associated publication
Age, Specimen part
View SamplesBackground: Glioblastoma multiforme (GBM) is the most aggressive and most lethal primary malignant brain tumor, correlated with survival rates of less than one year from the time of diagnosis. Current surgical procedure attempts to remove the bulk of the tumor mass, whereas GBM frequently recurs within 1-3cm from the primary tumor resection site. Molecular mechanisms involved in the recurrence of the tumor are still poorly understood. The aim of the study was to define the molecular signature of GBM surrounding white matter (WM) in order to better understand the molecular mechanisms involved with tumor relapse.
Gene expression profile of glioblastoma peritumoral tissue: an ex vivo study.
No sample metadata fields
View SamplesBACKGROUND: Several in vitro assays have been used to identify cancer stem cells (CSC), including expression of cell surface markers and Hoechst dye efflux properties. However, each of these methods has potential pitfalls that complicate interpretation of the results. Focusing on colon cancers (CC), the CD133 antigen has been proposed as a marker of colon CSC. However, conflicting results have been reported in the literature indicating the need of a systematic analysis of CSC within CC and a complete validation of markers for the isolation of these cells.
No associated publication
Specimen part, Cell line
View SamplesH69M cells derive from H69 small cell lung cancer cells subjected to prolonged treatment with HGF. Among the whole population of cells, a subset of more fibroblastic cells was isolated (H69M-mesenchymal). In this experiment we compared expression profiles of both cell lines
Targeting epithelial-to-mesenchymal transition with Met inhibitors reverts chemoresistance in small cell lung cancer.
Specimen part, Cell line
View SamplesIn rice (Oryza sativa L.), the haplotype at the multigenic SUBMERGENCE 1 (SUB1) locus determines survival of prolonged submergence. SUB1 encodes two or three group VII Ethylene Response Factor (ERF) family transcription factors, SUB1A, SUB1B and SUB1C. A highly submergence-inducible SUB1A allele is present in lines that are submergence tolerant. This gene is the determinant of submergence tolerance. Here, the heterologous ectopic expression of rice SUB1A and SUB1C in Arabidopsis thaliana was employed to assess the transcriptional network mobilized by ectopic expression of SUB1A and SUB1C.
Expression of rice SUB1A and SUB1C transcription factors in Arabidopsis uncovers flowering inhibition as a submergence tolerance mechanism.
Specimen part
View SamplesSymptoms of the dopamine dysregulation syndrome in patients with Parkinsons disease (PD) are close to those observed in psychostimulant addiction. This suggests that dopamine replacement therapy shares some properties with potentially addictive drugs. A remaining challenge is to understand the neuroadaptations leading to compulsive dopaminergic medication use.
No associated publication
Sex, Specimen part, Treatment
View SamplesTemporal changes of the expression levels of the complete human transcriptome during the first 24 hours following infection of IFN-pre-treated macrophages. This approach has allowed us to identify genes involved in the IFN signaling that have an impact on HIV-1 infection of macrophages
TRAF6 and IRF7 control HIV replication in macrophages.
Specimen part, Time
View Samples