LAA expression profiles on LSC compared to other tissues
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE68172 | GEO | 2015/04/23
SECONDARY ACCESSION(S): PRJNA281951
REPOSITORIES: GEO
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Project description:Leukemic stem cells (LSC) might be the source for leukemic disease self-renewal and account for disease relapse after treatment, which makes them a critical target for further therapeutic options. Leukemia associated antigens (LAA) might be suitable structures to be attacked by immunotherapeutic agents. We performed primary AML sample enrichment and microarray studies to define LAA expression levels in AML. We compared the LAA expression in the enriched CD34+CD38- AML fraction to that of enriched HSC of healthy donors and AML bulk cells (CD34+CD38+, CD34-CD38+ and CD34-CD38). Furthermore, we investigated the expression patterns of co-stimulatory molecules in LSC, bulk AML cells and enriched HSC, Conclusion: We demonstrated the differential expression of several LAA in LSC, and their suitability as target structures. We enriched primary AML samples using CD34 and CD38 as markers to compare LAA expression levels of LSC, HSC and AML bulk. LAA expression profiles comparing LSC, HSC and leukemic bulk AML citation: Leukemic progenitor cells are susceptible to targeting by stimulated cytotoxic T cells against immunogenic leukemia-associated antigens Vanessa Schneider, Lu Zhang, Markus Rojewski, Natalie Fekete, Hubert Schrezenmeier, Alexander Erle, Lars Bullinger, Susanne Hofmann, Marlies Götz, Konstanze Döhner, Susann Ihme, Hartmut Döhner, Christian Buske, Michaela Feuring-Buske, Jochen Greiner
2015-04-23 | E-GEOD-68172 | biostudies-arrayexpress
Project description:Tumors contain a fraction of cancer stem cells that maintain the propagation of the disease. The CD34CD38_ cells, isolated from acute myeloid leukemia (AML), were shown to be enriched leukemic stem cells (LSC). We isolated the CD34CD38_ cell fraction from AML and compared their gene expression profiles to the CD34CD38 cell fraction, using microarrays. We found 409 genes that were at least twofold over- or underexpressed between the two cell populations. These include underexpression of DNA repair, signal transduction and cell cycle genes, consistent with the relative quiescence of stem cells, and chromosomal aberrations and mutations of leukemic cells. Comparison of the LSC expression data to that of normal hematopoietic stem cells (HSC) revealed that 34% of the modulated genes are shared by both LSC and HSC, supporting the suggestion that the LSC originated within the HSC progenitors. We focused on the Notch pathway since Jagged-2, a Notch ligand was found to be overexpressed in the LSC samples. We show that DAPT, an inhibitor of gamma-secretase, a protease that is involved in Jagged and Notch signaling, inhibits LSC growth in colony formation assays. Identification of additional genes that regulate LSC self-renewal may provide new targets for therapy. Microarrays were used to compare the gene expression patterns between AML CD34+CD38- cells and AML CD34+CD38+
2011-12-01 | E-GEOD-34044 | biostudies-arrayexpress
Project description:Context: In many cancers, specific subpopulations of cells appear to be uniquely capable of initiating and maintaining tumors. The strongest support for this cancer stem cell model comes from transplantation assays in immune-deficient mice indicating that human acute myeloid leukemia (AML) is organized as a cellular hierarchy driven by self-renewing leukemia stem cells (LSC). This model has significant implications for the development of novel therapies, but its clinical significance remains unclear. Objective: To measure associations between a leukemic stem cell expression signature and clinical outcomes in AML. Design, Setting, and Patients: We defined a gene expression signature of LSC-enriched subpopulations from primary AML patient samples and xenografts, based on a functional definition in transplantation assays. Using previously published gene expression data of bulk AML from four independent cohorts totaling 1047 patients, we performed a retrospective cohort study, defining an LSC score and evaluating it for associations with known predictors of risk including cytogenetic subtype and molecular mutations, and as an independent prognostic factor. Main Outcome Measures: Reproducible associations between a leukemic stem cell signature and overall, event-free, and relapse-free survival. Results: The LSC score was similar across most AML subtypes, but was lower in promyelocytic leukemia, and prognostically favorable cases harboring NPM1 or CEBPA mutations. Strikingly, high scores associated with inferior overall (OS), event-free (EFS), and relapse-free survival (RFS) in these independent cohorts, whether considering patients with a normal karyotype [hazard ratio (HR) range for OS 1.13-1.18, p<0.012 in all cases], or those with cytogenetic anomalies (HR range for OS 1.07-1.15, p<0.01 in all cases). In multivariate analysis, the LSC score was associated with poor outcomes independently of age, FLT3 or NPM1 mutations, and cytogenetic risk group, and added to their prognostic value. Conclusions: High expression of a leukemic stem cell gene expression signature is independently associated with adverse outcomes in AML Cellular fractionation and expression profiling of normal and leukemic subsets: Human samples were obtained at the Stanford University Medical Center according to an approved protocol of the Institutional Review Board after informed consent. Normal human bone marrow mononuclear cells were purchased from AllCells Inc. (Emeryville, CA) and human cord blood was obtained from Stanford University. For AML specimens, peripheral blood and/or bone marrow was obtained, and gene expression microarray data were generated using Affymetrix U133 Plus 2.0 microarrays from the following populations purified by fluorescence-activated cell sorting: AML LSC (Lin-CD34+CD38-CD90-, n=7), AML LPC (Lin-CD34+CD38+, n=7), AML Blasts (Lin-CD34-), normal hematopoietic stem cells (HSC, Lin-CD34+CD38-CD90+CD45RA-; bone marrow and cord blood, n=7), multipotent progenitors (Lin-CD34+CD38-CD90-CD45RA-; bone marrow and cord blood, n=7), common myeloid progenitors (Lin-CD34+CD38+CD123+CD45RA-; bone marrow, n=4), granulocyte-monocyte progenitors (Lin-CD34+CD38+CD123+CD45RA+; bone marrow, n=4), and megakaryocyte-erthythrocyte progenitors (Lin-CD34+CD38+CD123-CD45RA-; bone marrow, n=4). Raw data were deposited at the National Center for Biotechnology Information Gene Expression Omnibus (GEO, accession GSE24006). Detailed methods for purification of cellular subsets and clinical features of the corresponding AML patients have been reported previously. Microarray analysis and definition of LSC signature: Fourteen paired LSC and LPC samples from 7 patients described above were combined with 16 paired samples (8 LSC and 8 LPC) from an independent study to produce one dataset for analysis. Individual genes differentially expressed between paired LSC and LPC were identified using Significance Analysis of Microarrays, employing a paired metric (false discovery rate<10%). The ‘LSC signature’ in a given dataset was defined as the first principal component of these genes (the linear weighted sum of gene expression values that summarizes the maximum possible proportion of their total variance) across samples from that dataset. The LSC signature was evaluated across all purified subpopulations described above. To identify biological themes distinguishing LSC from LPC, all genes on microarrays were ranked by their geometric mean difference in expression between paired LSC/LPC samples, and evaluated using Gene Set Enrichment Analysis. Raw microarray data were obtained as Affymetrix CEL files for four publicly available bulk AML gene expression studies from NCBI GEO (GSE12417, n=163 normal-karyotype AML only, with OS outcomes; GSE10358, n=184, OS and EFS; GSE14468, n=527, OS, EFS and RFS) and the National Cancer Institute caArray database (accession willm-00119, n=170 non-FAB M3, OS only). Matrices of re-analyzed data linked below as supplementary files. Ingenuity Pathways Analysis was used to identify interaction networks of genes.
2010-12-22 | E-GEOD-24006 | biostudies-arrayexpress
Project description:In an attempt to identify novel markers and immunologic targets in leukemic stem cells (LSC) in acute myeloid leukemia (AML) and chronic myeloid leukemia (CML), we screened samples of patients with AML, CML, and controls for expression of cell surface antigens on CD34+/CD38− and CD34+/CD38+ cells by multi-color flow cytometry. In addition, we examined mRNA expression profiles in highly purified CD34+/CD38− and CD34+/CD38+ cells by gene array- and qPCR analyses. Aberrantly expressed markers were identified in all patient cohorts examined.
2020-09-21 | GSE138883 | GEO
Project description:We applied a novel approach of parallel transcriptional analysis of multiple, highly fractionated stem and progenitor populations in a genetically defined subset of AML (AML with monosomy 7). We isolated phenotypic long-term HSC (LT-HSC), short-term HSC (ST-HSC), and committed granulocyte-monocyte progenitors (GMP) from individual patients with AML, and measured gene expression profiles of each population, and in comparison to their phenotypic counterparts from age-matched healthy controls. Bone marrow samples from AML patients bearing monosomy 7 and age-matched healthy controls were used in this study. Hematopoietic stem and progenitor compartments were purified by multiparameter-high speed fluorescence-activated cell sorting (FACS) from CD34+ enriched bone marrow to isolate LT-HSC (Lin-/CD34+/CD38-/CD90+), ST-HSC (Lin-/CD34+/CD38-/CD90-), and GMP (Lin-/CD34+/CD38+/CD123+/CD45R+).
2012-09-05 | E-GEOD-35010 | biostudies-arrayexpress
Project description:We applied a novel approach of parallel transcriptional analysis of multiple, highly fractionated stem and progenitor populations from patients with acute myeloid leukemia (AML) and a normal karyotype. We isolated phenotypic long-term HSC (LT-HSC), short-term HSC (ST-HSC), and committed granulocyte-monocyte progenitors (GMP) from individual patients, and measured gene expression profiles of each population, and in comparison to their phenotypic counterparts from age-matched healthy controls. Bone marrow samples from AML patients with normal karyotype and age-matched healthy controls were used in this study. Hematopoietic stem and progenitor compartments were purified by multiparameter-high speed fluorescence-activated cell sorting (FACS) from CD34+ enriched bone marrow to isolate LT-HSC (Lin-/CD34+/CD38-/CD90+), ST-HSC (Lin-/CD34+/CD38-/CD90-), and GMP (Lin-/CD34+/CD38+/CD123+/CD45R+).
2012-09-05 | E-GEOD-35008 | biostudies-arrayexpress
Project description:We performed the first genome-wide expression analysis directly comparing the expression profile of highly enriched normal human hematopoietic stem cells (HSC) and leukemic stem cells (LSC) from patients with acute myeloid leukemia (AML). Comparing the expression signature of normal HSC to that of LSC, we identified 3,005 differentially expressed genes. Using 2 independent analyses, we identified multiple pathways that are aberrantly regulated in leukemic stem cells compared with normal HSC. Several pathways, including Wnt signaling, MAP Kinase signaling, and Adherens Junction, are well known for their role in cancer development and stem cell biology. Other pathways have not been previously implicated in the regulation of cancer stem cell functions, including Ribosome and T Cell Receptor Signaling pathway. This study demonstrates that combining global gene expression analysis with detailed annotated pathway resources applied to highly enriched normal and malignant stem cell populations, can yield an understanding of the critical pathways regulating cancer stem cells. Experiment Overall Design: Total RNAs were isolated from both AML stem cells (9 patients) and normal bone marrow hematopoietic stem cells (HSCs) (4 control subjects).
2009-08-12 | E-GEOD-17054 | biostudies-arrayexpress
Project description:The leukemia stem cell (LSC) populations of acute myeloid leukemia (AML) exhibit phenotypic, genetic and functional heterogeneity that contribute to therapy failure and relapse. Progress towards understanding the mechanistic basis for therapy resistance in LSCs has been hampered by difficulties in isolating cell fractions that enrich for the entire heterogeneous population of LSCs within individual AML samples. We previously reported that CD200 gene expression is upregulated in LSC-containing AML fractions. We demonstrate that CD200 is present on a greater proportion of CD45dim blasts compared to more differentiated CD45high cells in AML patient samples. In 75% of AML cases examined, CD200 was expressed on 10% of CD45dim blasts; of these, CD200 identified LSCs within the blast population in 90% of samples tested in xenotransplantation assays. Notably, CD200 expression captured both CD34- and CD34- LSCs within individual AML samples. Highly purified CD45dimCD200+ LSC-containing blasts were enriched in primitive HSC/progenitor-like signatures, while CD45dimCD200- nonengrafting blasts were enriched in myeloid-like signature. Moreover, analysis of CD45dimCD200+ blasts from NPM1-mutated AMLs also demonstrated an enrichment of primitive gene expression signatures compared to unfractionated (bulk) cells.
2020-10-10 | GSE159322 | GEO
Project description:The leukemia stem cell (LSC) populations of acute myeloid leukemia (AML) exhibit phenotypic, genetic and functional heterogeneity that contribute to therapy failure and relapse. Progress towards understanding the mechanistic basis for therapy resistance in LSCs has been hampered by difficulties in isolating cell fractions that enrich for the entire heterogeneous population of LSCs within individual AML samples. We previously reported that CD200 gene expression is upregulated in LSC-containing AML fractions. We demonstrate that CD200 is present on a greater proportion of CD45dim blasts compared to more differentiated CD45high cells in AML patient samples. In 75% of AML cases examined, CD200 was expressed on 10% of CD45dim blasts; of these, CD200 identified LSCs within the blast population in 90% of samples tested in xenotransplantation assays. Notably, CD200 expression captured both CD34- and CD34- LSCs within individual AML samples. Highly purified CD45dimCD200+ LSC-containing blasts were enriched in primitive HSC/progenitor-like signatures, while CD45dimCD200- nonengrafting blasts were enriched in myeloid-like signature. Moreover, analysis of CD45dimCD200+ blasts from NPM1-mutated AMLs also demonstrated an enrichment of primitive gene expression signatures compared to unfractionated (bulk) cells.
2020-10-10 | GSE159321 | GEO
Project description:The leukemia stem cell (LSC) populations of acute myeloid leukemia (AML) exhibit phenotypic, genetic and functional heterogeneity that contribute to therapy failure and relapse. Progress towards understanding the mechanistic basis for therapy resistance in LSCs has been hampered by difficulties in isolating cell fractions that enrich for the entire heterogeneous population of LSCs within individual AML samples. We previously reported that CD200 gene expression is upregulated in LSC-containing AML fractions. We demonstrate that CD200 is present on a greater proportion of CD45dim blasts compared to more differentiated CD45high cells in AML patient samples. In 75% of AML cases examined, CD200 was expressed on 10% of CD45dim blasts; of these, CD200 identified LSCs within the blast population in 90% of samples tested in xenotransplantation assays. Notably, CD200 expression captured both CD34- and CD34- LSCs within individual AML samples. Highly purified CD45dimCD200+ LSC-containing blasts were enriched in primitive HSC/progenitor-like signatures, while CD45dimCD200- nonengrafting blasts were enriched in myeloid-like signature. Moreover, analysis of CD45dimCD200+ blasts from NPM1-mutated AMLs also demonstrated an enrichment of primitive gene expression signatures compared to unfractionated (bulk) cells.
2020-10-10 | GSE159319 | GEO