Effective Targeting of Quiescent Chronic Myelogenous Leukemia Stem Cells by Histone Deacetylase Inhibitors in Combination with Imatinib Mesylate
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE20876 | GEO | 2010/05/20
SECONDARY ACCESSION(S): PRJNA124671
REPOSITORIES: GEO
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Project description:We investigated the ability of HDAC inhibitors (HDACi) to target CML stem cells. Treatment with HDACi combined with IM effectively induced apoptosis in quiescent CML progenitors resistant to elimination by IM alone, and eliminated CML stem cells capable of engrafting immunodeficient mice. In vivo administration of HDACi with IM markedly diminished LSC in a transgenic mouse model of CML. The interaction of IM and HDACi inhibited genes regulating hematopoietic stem cell maintenance and survival. HDACi treatment represents a novel and effective strategy to target LSC in CML patients receiving tyrosine kinase inhibitors. CML CD34+CD38- cells were selected using flow cytometry sorting and treated with IM, LBH and the combination of IM and LBH or cultured without exposure to drugs (controls) for 24 hours (n=3 each). Total RNA from 5000 cells was extracted using the RNeasy kit (Qiagen), amplified and labeled using GeneChip Two-Cycle Target Labeling and Control Reagents (Affymetrix, Santa Clara, CA). 15 µg cRNA from each sample was hybridized to Affymetrix GeneChip Human Genome U133 Plus 2.0 Arrays. Microarray data analyses were performed using R (version 2.9) with genomic analysis packages from Bioconductor (version 2.4). Expression data were normalized using the robust multiarray average (RMA) algorithm, with background adjustment, quantile normalization and median polish summarization. Probesets with low expression levels or low variability across samples were filtered. For genes with multiple probesets, the gene level expression was set to be the median of the probesets. Linear regression was used to model the gene expression with the consideration of 2x2 factorial design and matched samples. Differentially expressed genes were identified by calculating empirical Bayes moderated t-statistic, and p-values were adjusted by FDR using the âLIMMAâ package. Gene Set Enrichment Analyses (GSEA) was performed using GSEA software version 2.04 [http://www.broadinstitute.org/gsea/] to detect enrichment of predetermined gene sets using t-scores and gene sets in C2 (curated gene sets) category from the Molecular Signature Database (MsigDB). Gene sets representing common functional categories were categorized and grouped. We also analyzed enrichment of gene sets with common transcription factor binding sites (586 sets) from MsigDB.
2010-06-08 | E-GEOD-20876 | biostudies-arrayexpress
Project description:Leukemia stem cells (LSC) in chronic myelogenous leukemia (CML) resist elimination with tyrosine kinase inhibitors (TKI) and persist as a source of disease recurrence. LSC populations are heterogeneous, but the most primitive, drug-resistant subsets are not well characterized. Previous studies indicate that variable cell-surface expression of the c-Kit receptor identifies heterogeneous hematopoietic stem cells (HSC) populations. We found that c-Kit expression is reduced on CML LSC compared to normal HSC. Long-term engraftment and leukemia generation capacity was restricted to low c-Kit expressing (c-KitLow) LSC, which showed increased quiescence and inflammatory gene signatures expression. The c-Kit ligand, stem cell factor (SCF), expanded normal HSC but drove maturation of CML LSC. The proportion of c-Kitlow LT-HSC was increased with TKI treatment. Supplementary SCF treatment enhanced elimination of committed but not primitive CML LT-HSC in TKI-treated mice. Low c-Kit expression identifies primitive, treatment-resistant LSC subpopulations with distinct regulatory characteristics, that are critical therapeutic targets.
2022-11-29 | GSE180496 | GEO
Project description:ABL1 kinase inhibitors such as imatinib mesylate (IM) are effective in managing chronic myelogenous leukemia (CML) but incapable of eliminating leukemia stem cells (LSCs), suggesting that kinase−independent pathways support LSC survival. Given that the bone marrow hypoxic microenvironment supports hematopoietic stem cells, we investigated if hypoxia similarly contributes to LSC persistence. Importantly, we found that while BCR−ABL1 kinase remained effectively inhibited by IM under hypoxia, apoptosis became partially suppressed. Furthermore, hypoxia enhanced the clonogenicity of CML cells, as well as their efficiency in repopulating immunodeficient mice, both in the presence and absence of IM. HIF1−α, which is the master regulator of the hypoxia transcriptional response is expressed in the bone marrow specimens of CML individuals. In vitro, HIF1−α is stabilized during hypoxia and its expression and transcriptional activity can be partially attenuated by concurrent IM treatment. Expression analysis demonstrates at the whole transcriptome level that hypoxia and IM regulate distinct subsets of genes. Functionally, knockdown of HIF1−α abolished the enhanced clonogenicity during hypoxia. Taken together, our results suggest that in the hypoxic microenvironment, HIF1−α signaling supports LSC persistence independently of BCR−ABL1 kinase activity. Thus targeting HIF1−α and its pathway components may be therapeutically important for the complete eradication of LSCs.
2014-06-03 | GSE48294 | GEO
Project description:Chronic myelogenous leukemia (CML) is a malignant stem cell disease characterized by a reciprocal translocation between chromosome 9 and 22. The selective bcr-abl tyrosine-kinase inhibitor Imatinib has become the therapy of choice for patients with newly diagnosed CML including those previously considered candidates for allogeneic haematopoietic stem cell transplantation. The tyrosine-kinase inhibitor Nilotinib is a derivate of Imatinib with higher potency. To examine the molecular and functional effects of Nilotinib and Imatinib in chronic myelogenous leukemia, we performed gene expression and functional analyses in K562 cells following treatment with the two tyrosine kinase inhibitors.
2009-12-19 | GSE19567 | GEO
Project description:Using a CML mouse model, we identified differences in gene expression between leukemic compared with non-leukemic LTHSC, including increased expression of the thrombopoietin (THPO) receptor MPL. LTHSC expressing high levels of MPL showed enhanced JAK/STAT signaling and proliferation in response to THPO in vitro, and increased leukemogenic capacity in vivo compared to LTHSC with low MPL expression. Although both G0 and S-phase subpopulations were increased in MPL expressing LTHSC, LSC capacity was restricted to quiescent cells. Inhibition of MPL expression in CML LTHSC resulted in reduced THPO-induced JAK/STAT signaling and leukemogenic potential. Similar observations were made with LTHSC from CML patients. MPL expressing LTHSC demonstrated reduced sensitivity to BCR-ABL TKI treatment but demonstrated increased sensitivity to JAK inhibitors. Our studies identify MPL expression levels as a key determinant of heterogeneous leukemia-initiating capacity and drug sensitivity of CML LTHSC, and suggest that MPL-expressing CML stem cells are critical targets for therapy. To evaluate heterogeneity in LSC potential, donor LTHSC from SCL-tTA/BCR-ABL mice (200 cells/mouse) were transplanted into a cohort of congenic FVBN mice. Recipient mice were followed for engraftment of donor CML cells and development of CML. LTHSCs were isolated from leukemic and non-leukemic recipient mice and global gene expression was analyzed using RNA-Seq.
2016-06-01 | E-GEOD-76123 | biostudies-arrayexpress
Project description:ABL1 kinase inhibitors such as imatinib mesylate (IM) are effective in managing chronic myelogenous leukemia (CML) but incapable of eliminating leukemia stem cells (LSCs), suggesting that kinaseM-bM-^HM-^Rindependent pathways support LSC survival. Given that the bone marrow hypoxic microenvironment supports hematopoietic stem cells, we investigated if hypoxia similarly contributes to LSC persistence. Importantly, we found that while BCRM-bM-^HM-^RABL1 kinase remained effectively inhibited by IM under hypoxia, apoptosis became partially suppressed. Furthermore, hypoxia enhanced the clonogenicity of CML cells, as well as their efficiency in repopulating immunodeficient mice, both in the presence and absence of IM. HIF1M-bM-^HM-^RM-NM-1, which is the master regulator of the hypoxia transcriptional response is expressed in the bone marrow specimens of CML individuals. In vitro, HIF1M-bM-^HM-^RM-NM-1 is stabilized during hypoxia and its expression and transcriptional activity can be partially attenuated by concurrent IM treatment. Expression analysis demonstrates at the whole transcriptome level that hypoxia and IM regulate distinct subsets of genes. Functionally, knockdown of HIF1M-bM-^HM-^RM-NM-1 abolished the enhanced clonogenicity during hypoxia. Taken together, our results suggest that in the hypoxic microenvironment, HIF1M-bM-^HM-^RM-NM-1 signaling supports LSC persistence independently of BCRM-bM-^HM-^RABL1 kinase activity. Thus targeting HIF1M-bM-^HM-^RM-NM-1 and its pathway components may be therapeutically important for the complete eradication of LSCs. 24 samples consisting CD34+ bone marrow aspirates of 3 chronic phase patients that were subjected to 24h or 96h of DMSO/Normoxia (21% oxygen, 5% carbon dioxide) control, 2 M-BM-5M Imatinib, hypoxia (0.5% oxygen, 5% carbon dioxide) or combined Imatinib/hypoxia treatments in triplicate cultures.
2014-06-03 | E-GEOD-48294 | biostudies-arrayexpress
Project description:An approximately 40% of chronic myeloid leukemia (CML) patients who discontinued imatinib (IM) therapy maintained undetectable minimal residual disease (UMRD) for more than one year (STOP-IM). We set out to examine plasma miRNAs expression in CML patients who could discontinue IM, to seek the possible distinguishable biomarker in STOP-IM CML patients. We compared CML patients who sustained UMRD for more than one year after discontinuation of imatinib (STOP-IM group) with healthy volunteers (controls).
2016-03-31 | GSE75391 | GEO
Project description:An approximately 40% of chronic myeloid leukemia (CML) patients who discontinued imatinib (IM) therapy maintained undetectable minimal residual disease (UMRD) for more than one year (STOP-IM). We therefore set out to examine exosomal miRNAs expression in CML patients who could discontinue IM, to seek the possible distinguishable biomarker in STOP-IM CML patients. We compared CML patients who sustained UMRD for more than one year after discontinuation of imatinib (STOP-IM group) with healthy volunteers (controls).
2016-03-31 | GSE75389 | GEO
Project description:The outcome of treating chronic myeloid leukemia (CML) with imatinib mesylate (IM) is inferior when therapy is commenced in late chronic or accelerated phase as compared to early chronic phase. This may be attributed to additional genomic alterations that accumulate during disease progression. We sought to identify such lesions in patients showing suboptimal response to IM by performing array-CGH analysis on 39 sequential samples from 15 CML patients. Seventy-four cumulative copy number alterations (CNAs) consisting of 35 losses and 39 gains were identified. Alterations flanking the ABL1 and BCR genes on chromosomes 9 and 22, respectively, were the most common identified lesions with 5 patients losing variable portions of 9q34.11 proximal to ABL1. Losses involving 1p36, 5q31, 17q25, Y and gains of 3q21, 8q24, 22q11, Xp11 were among other recurrent lesions identified. Aberrations were also observed in individual patients, involving regions containing known leukemia-associated genes; CDKN2A/2B, IKZF1, RB1, TLX1, AFF4. CML patients in late stages of their disease, harbor pre-existing and evolving sub-microscopic CNAs that may influence disease progression and IM response.
2011-03-15 | GSE23946 | GEO
Project description:Tyrosine kinase inhibitors (TKI) are highly effective in treatment of chronic myeloid leukemia (CML) but do not eliminate leukemia stem cells (LSC), which remain a potential source of relapse. TKI treatment effectively inhibits BCR-ABL kinase activity in CML LSC, suggesting that additional kinase-independent mechanisms contribute to LSC preservation. We investigated whether signals from the bone marrow (BM) microenvironment protect CML LSC from TKI treatment. Coculture with human BM mesenchymal stromal cells (MSC) significantly inhibited apoptosis and preserved CML stem/progenitor cells following TKI exposure, maintaining colony forming ability and engraftment potential in immunodeficient mice. We found that the N-Cadherin receptor plays an important role in MSC-mediated protection of CML progenitors from TKI. N-Cadherin-mediated adhesion to MSC was associated with increased cytoplasmic N-Cadherin-M-NM-2-catenin complex formation, as well as enhanced M-NM-2-catenin nuclear translocation and transcriptional activity. Increased exogenous Wnt-mediated M-NM-2-catenin signaling played an important role in MSC-mediated protection of CML progenitors from TKI treatment. Our results reveal a close interplay between N-Cadherin and the Wnt-M-NM-2-catenin pathway in protecting CML LSC during TKI treatment. Importantly, these results reveal novel mechanisms of resistance of CML LSC to TKI treatment, and suggest new targets for treatment designed to eradicate residual LSC in CML patients. RNA was obtained from CML CD34+ cells treated with or without IM (5M-NM-<M) and MSC for 96 hours, amplified, labeled and hybridized to GeneChip 1.0 arrays (Affymetrix, Santa Clara, CA). Microarray data analysis was performed using R (version 2.9) with genomic analysis packages from Bioconductor (version 2.4). The 33297 probes represented on the microarray were filtered by cross-sample mean, and for standard deviation of greater than the 25% quantile, yielding 18624 probes representing 12553 genes. Linear regression was used to model the gene expression with the consideration of a 2x2 factorial design and matched samples. Differentially expressed genes were identified by calculating empirical Bayes moderated t-statistic, and p-values were adjusted by FDR using the M-bM-^@M-^\LIMMAM-bM-^@M-^] package. Gene Set Enrichment Analysis (GSEA) was performed using GSEA software version 2.04 to detect enrichment of predetermined gene sets using t-scores from all genes for 1263 gene sets in the C2 (curated gene sets) category from the Molecular Signature Database (MsigDB).
2013-01-01 | E-GEOD-43225 | biostudies-arrayexpress