Project description:Treatment for acute myeloid leukemia (AML) remains suboptimal and many patients remain refractory or relapse upon standard chemotherapy based on nucleoside analogs plus anthracyclines. The crosstalk between AML cells and the bone marrow (BM) stroma is a major mechanism underlying therapy resistance in AML. Lenalidomide and pomalidomide, a new generation immunomodulatory drugs (IMiDs), possess pleiotropic anti-leukemic properties including potent immune-modulating effects and are commonly used in hematological malignances associated with intrinsic dysfunctional BM such as myelodysplastic syndromes and multiple myeloma. Whether IMiDs may improve the efficacy of current standard treatment in AML remains understudied. Here, we have exploited in vitro and in vivo preclinical AML models to analyze whether IMiDs potentiate the efficacy of AraC/Iradubicin (standard AML chemotherapy) by interfering with the BM stroma-mediated chemoresistance. We report that lenalidomide and pomalidomide have cytotoxic effects on neither AML cells nor BM-MSCs, but they increase the immunosuppressive/immunomodulatory properties of BM-MSCs. When combined with AraC and Idarubicin, IMiDs fail to circumvent BM stroma-mediated resistance of AML cells in vitro and in vivo but induce robust extramedullary mobilization of AML cells. When administered as a single agent, lenalidomide highly mobilizes AML cells, but not healthy CD34+ cells, to peripheral blood (PB) likely through specific downregulation of CXCR4 in AML blasts. Global gene expression profiling supports a migratory/mobilization gene signature in lenalidomide-treated AML blasts but not in CD34+ cells. Collectively, IMiDs mobilize AML blasts to PB through downregulation of CXCR4 but do not improve AraC/Idarubicin activity in a preclinical model of AML.
Project description:miRNA expression in a patient with AML comparing with pooled CD34 hematopoietic progenitor cells from 5 healthy volunteers RNA from bone marrow of a patient with AML with more than 90% blast and RNA pooled from 5 volunteers with CD34+ cells selected by automacs from bone marrow
Project description:To evaluate the transcriptome and splicing repertoire of bulk CD34+ sorted bone marrow progenitors we performed RNA-Seq. These data highlight an AML prognostic splicing signature that is present in healthy donors at equivalent frequencies to that found in AML bone marrow.
Project description:AML blasts and CD34+ normal progenitors were treated with SAHA, and gene expression profiles were compared to 6-hours treatments. The analysis revealed commonly regulated genes in these systems by HDACi.
Project description:Acute myeloid leukemia (AML) is one of the most common and deadly forms of hematopoietic malignancies. We hypothesized that microarray studies could identify previously unrecognized expression changes that only occur only in AML blasts. We were particularly interested in those genes with increased expression in AML, believing that these genes may be potential therapeutic targets. Experiment Overall Design: We compared gene expression profiles between normal hematopoietic cells from 38 healthy donors and leukemic blasts from 26 AML patients. Normal hematopoietic samples included CD34+ selected cells (N = 18), unselected bone marrows (N = 10), and unselected peripheral bloods (N = 10).
Project description:In patients with mast cell leukemia, the CD34+ bone marrow fraction contains a subset of disease-initiating and propagating cells. The aim of this study was to compare the gene expression profile of these cells with that of CD34+ cells obtained from the bone marrow of healthy donors, in order to find aberrantly expressed genes and pathways.
Project description:mRNA samples from bone marrow CD34+ cells (HSC) from healthy donors after co-culture assays (Control condition, with hMSCs and CD34+ cells from healthy donors; and AML condition, with hMSCs-AML and CD34+ cells from donors) were amplified, labeled and hybridized to the ClariomTM S Array human (Thermo Scientific, USA). Normalization and analysis of microarray data was performed using the Transcriptome Analysis Console (TAC) software (Affymetrix, USA).
Project description:The label-free quantitative proteome was generated for 42 primary AML patient samples enriched for CD34+ cells (or mononuclear cells in the case of NPMcyt sameples) and as controls 6 mobilized peripheral blood CD34+ cells were included. Furthermore, 6 AML cell lines were included, and also primary mesenchymal stem cells grown under normaoxia or hypoxia were included.
Project description:Control group is an essential part of the research design which provide a baseline by elimating variables, bias and other factors that skew the data. Human CD34+ cells are generally used as controls to study myeloid malignancies. This study determines whether fresh or short term cytokine induced CD34+ HSPCs can provide a more appropriate normal control (compared to AML blasts) for target discovery studies. We here determine that the GEP of CD34+ cells that do not undergo ex vivo expansion best match the GEP of minimally differentiated AML blasts and would serve as a better control to identify novel targets in the AML blast population.