Gene expression profiling in the leukemic stem cell-enriched CD34+ fraction identifies target genes that predict prognosis in normal karyotype AML
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ABSTRACT: Mononuclear cells from AML patients (n=46) were sorted into CD34+ and CD34- subfractions and genome-wide expression analysis was performed using Illumina BeadChip Arrays (HT12 v3). Of 2 AML samples only the CD34+ fraction could be analyzed. AML CD34+ and CD34- gene expression was compared to a large group of normal CD34+ bone marrow cells (n=31).
Project description:Mononuclear cells from AML patients (n=46) were sorted into CD34+ and CD34- subfractions and genome-wide expression analysis was performed using Illumina BeadChip Arrays (HT12 v3). Of 2 AML samples only the CD34+ fraction could be analyzed. AML CD34+ and CD34- gene expression was compared to a large group of normal CD34+ bone marrow cells (n=31). Mononuclear cells from AML patients (n=46) were sorted into CD34+ (46) and CD34- (44) subfractions and genome-wide expression analysis was performed using Illumina BeadChip Arrays (HT12 v3). AML CD34+ and CD34- gene expression was compared to a large group of normal CD34+ bone marrow cells (n=31).
Project description:To comprehensibly understand the genes and pathways associated with TMIGD2 expression in CD34-expressing leukemia cells, RNA-seq was conducted on FACS-purified CD34+TMIGD2+ and CD34+TMIGD2- subfractions of six primary AML specimens.
Project description:CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT#L and TPO for 48 hrs. Cells were transduced with control MiNR1 or STAT5A-ER in three rounds over 48 hrs. Hematopoietic stem cells (HSCs), common myeloid progenitors (CMPs), granulocyte/macrophage progenitors (GMPs), and megakaryocyte/erythroid progenitors (MEPs) were sorted (for details see Blood 2011, Fatrai et al). cells were stimulated with 100 ng/ml 4OHT for 24 hrs after which RNA was isolated for Illumina beadhchiop arrays HT12 v3 CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT#L and TPO for 48 hrs. Cells were transduced with control MiNR1 or STAT5A-ER in three rounds over 48 hrs. Hematopoietic stem cells (HSCs), common myeloid progenitors (CMPs), granulocyte/macrophage progenitors (GMPs), and megakaryocyte/erythroid progenitors (MEPs) were sorted (for details see Blood 2011, Fatrai et al). cells were stimulated with 100 ng/ml 4OHT for 24 hrs after which RNA was isolated for Illumina beadhchiop arrays HT12 v3
Project description:CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT#L and TPO for 48 hrs. Cells were transduced with control MiNR1 or STAT5A-ER in three rounds over 48 hrs. Hematopoietic stem cells (HSCs), common myeloid progenitors (CMPs), granulocyte/macrophage progenitors (GMPs), and megakaryocyte/erythroid progenitors (MEPs) were sorted (for details see Blood 2011, Fatrai et al). cells were stimulated with 100 ng/ml 4OHT for 24 hrs after which RNA was isolated for Illumina beadhchiop arrays HT12 v3
Project description:AML with mutated NPM1 usually carries normal karyotype (NK) but it may harbor chromosomal aberrations whose significance remains unclear. We addressed this question in 631 AML patients with mutated/cytoplasmic NPM1. An abnormal karyotype (AK) was present in 93/631 cases (14.7%), the most frequent abnormalities being +8, +4, -Y, del(9q), +21. Chromosome aberrations in NPM1-mutated AML were similar to, but occurred less frequently than additional chromosome changes found in other AML with recurrent cytogenetic abnormalities according to WHO classification. Four of the 31 NPM1-mutated AML patients karyotyped at different time points had NK at diagnosis but AK at relapse: del(9q) (n=2), t(2;11) (n=1), inv(12) (n=1). NPM1-mutated AML with NK or AK showed overlapping morphological, immunophenotypic (CD34-negativity) and gene expression profile (downregulation of CD34 and upregulation of HOX genes). No difference in survival was observed among NPM1-mutated AML patients independently of whether they carried a normal or abnormal karyotype, the NPM1-mutated/FLT3-ITD negative cases showing the better prognosis. Findings in our patients point to chromosomal aberrations as secondary events, reinforce the concept that NPM1 mutation is a founder genetic lesion and indicate that NPM1-mutated AML should be clinically handled as one entity, irrespective of the karyotype.
Project description:High expression of CDK7, a cell cycle regulator and transcriptional modulator, correlates with poor outcomes in acute myeloid leukemia (AML). We report that TGN-1062, a novel CDK7 inhibitor, exhibits significant antileukemic effects by inhibiting cell growth and inducing apoptosis in AML cell lines and primary CD34+CD38- blasts (enriched for leukemia stem cells; LSCs), while sparing normal CD34+CD38- cells (enriched for hematopoietic stem cells; HSCs). Our study revealed that TGN-1062 treatment in primary CD34+CD38- AML blasts suppress RNA m6A modification by downregulating METTL3/14 proteins, key components of the m6A methyltransferase complex that regulate RNA stability and translation. Decrease in METTL proteins reduced BCL-2 m6A RNA modification and led to increased BCL-2 mRNA decay and protein levels. BCL-2 downregulation resulted in disruption of mitochondrial metabolism and mitofusion in LSCs through decrease of HMGB1/HSPB1 and NRF2/DRP1 signaling, respectively. In vivo, TGN-1062 significantly reduced leukemia burden and prolonged survival in a murine MllPTD/WT/Flt3ITD/ITD AML model and in FLT3-WT and inv(16) AML patient-derived xenografts (PDXs). Increased survival in secondary transplant experiments supported TGN-1062 activity on LSCs. Of note, we proved that TGN-1062 synergized with the BCL-2 inhibitor, venetoclax in eliminating LSCs in both murine and PDX AML models, underscoring its potential as a promising therapeutic approach for AML patients.
Project description:Leukemia is characterized by genetic and epigenetic mutations resulting in selection of cancer stem cells, which are unable to differentiate. While genetic alterations are difficult to target, the epigenome is intrinsically dynamic and readily offers new therapeutic strategies. Thus, identifying cancer-specific context-dependent targets and unraveling their biological function may open up new therapeutic perspectives. Here, we identify bromodomain-containing protein 9 (BRD9) as a critical target required in acute myeloid leukemia (AML). We show that BRD9 is overexpressed in AML cells including ex vivo primary blasts compared to CD34+. By targeting BRD9 expression in AML, we observed an alteration in proliferation and survival, ultimately resulting in the induction of apoptosis. Intriguingly, genome-wide profiling revealed that BRD9 binds enhancer regions in a cell type-specific manner, regulating cell type-related processes. We unveil a novel BRD9-sustained STAT5 pathway activation via regulation of SOC3 expression levels. Our findings identify a previously undescribed BRD9-STAT5 axis as critical for leukemia maintenance, suggesting BRD9 as a potential therapeutic target.
Project description:AML with mutated NPM1 usually carries normal karyotype (NK) but it may harbor chromosomal aberrations whose significance remains unclear. We addressed this question in 631 AML patients with mutated/cytoplasmic NPM1. An abnormal karyotype (AK) was present in 93/631 cases (14.7%), the most frequent abnormalities being +8, +4, -Y, del(9q), +21. Chromosome aberrations in NPM1-mutated AML were similar to, but occurred less frequently than additional chromosome changes found in other AML with recurrent cytogenetic abnormalities according to WHO classification. Four of the 31 NPM1-mutated AML patients karyotyped at different time points had NK at diagnosis but AK at relapse: del(9q) (n=2), t(2;11) (n=1), inv(12) (n=1). NPM1-mutated AML with NK or AK showed overlapping morphological, immunophenotypic (CD34-negativity) and gene expression profile (downregulation of CD34 and upregulation of HOX genes). No difference in survival was observed among NPM1-mutated AML patients independently of whether they carried a normal or abnormal karyotype, the NPM1-mutated/FLT3-ITD negative cases showing the better prognosis. Findings in our patients point to chromosomal aberrations as secondary events, reinforce the concept that NPM1 mutation is a founder genetic lesion and indicate that NPM1-mutated AML should be clinically handled as one entity, irrespective of the karyotype. All bone marrow samples were obtained from untreated patients at the time of diagnosis. Cells used for microarray analysis were collected from the purified fraction of mononuclear cells after Ficoll density centrifugation.
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+).