Abstract LB-45: High aldehyde dehydrogenase activity is a marker for normal hematopoietic stem cells but not leukemic stem cells in acute myeloid leukemia: novel therapeutic implications.

2011 ◽  
Author(s):  
Gerrit Jan Schuurhuis ◽  
Lisa A. Min ◽  
Michael H. Meel ◽  
Rolf Wouters ◽  
Monique Terwijn ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Aldehyde Dehydrogenase ◽  
Myeloid Leukemia ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Therapeutic Implications ◽  
Acute Myeloid ◽  
Novel Therapeutic ◽  
Aldehyde Dehydrogenase Activity

Gfi1b-A Novel Tumor Suppressor In Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3795-3795
Author(s):  
Lacramioara Botezatu ◽  
Judith Hönes ◽  
Amos Zeller ◽  
Lars C. Michel ◽  
Andre Görgens ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Transcription Factors ◽  
Tumor Suppressor ◽  
Myeloid Leukemia ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Blast Cells ◽  
Leukemia Development ◽  
Acute Myeloid

Abstract The proper differentiation of hematopoietic stem cells is regulated by a concert of different so called transcription factors. Growth Factor Independence 1b (Gfi1b) is a repressing transcription factor, which is pivotal for the proper emergence and maturation of erythrocytes and platelets. Furthermore, Gfi1b controls quiescence as well as cell cycle progression of hematopoietic stem cells and early progenitor cells. It has been shown for other transcription factors that a disturbed function of these transcription factors can be the basis of malignant diseases such acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). MDS is characterized by disturbed differentiation of one or several hematopoietic lineages. The accumulation of malignant blast cells, which are arrested in their development, is a key feature of AML. Since transcription factors play a role in AML development, we sought to investigate whether Gfi1b might also play a role in the development and progression of AML. Based on published gene expression arrays and own patient samples, we observed that Gfi1b is expressed at a lower level in leukemic blasts and leukemic stem cells compared to the non-malignant control cells. We correlated Gfi1b expression level in blast cells of patients from Essen and we found out that patients with high Gfi1b levels had a poor prognosis and an increased risk of relapse. In contrast low levels of Gfi1b expression were associated with a good prognosis. To test how different levels of Gfi1b might influence initiation of AML we have mouse strains available expressing Gfi1b at different expression levels. We have Gfi1b wt mice with one allele of Gfi1b deleted (Gfi1b het) and Gfi1b conditional mice, in which the expression of Gf1b (Mx Cre tg Gfi1b fl/fl) can be abrogated after injecting these mice with pIpC. To explore the role of Gfi1b in leukemia development, we used different murine AML models, resembling human leukemia. First these mice were crossed with Nup98HoxD13 transgenic mice, a mouse strain that develops a disease similar to the human MDS. We observed that Gfi1b heterozygosity (n=15) accelerated AML development (p=0,03) compared to wt mice (n=16). More importantly, complete absence of Gfi1b (n=8) results in a substantially earlier onset of AML, with a median survival time of about 50 days (p=0.002). To confirm our findings, we used a different murine AML model. Recurrent so called oncofusion proteins such as AML1-Eto9a, CBFbeta-Myh11 or MLL-AF9 are characteristic for certain subtypes of AML. We transduced Lineage negative (Lin-) bone marrow cells from wt, Gfi1b heterozygous (Gfi1b het) and Gfi1b deficient (MxCre Gfi1b fl/fl) mice with retroviruses encoding either AML1-Eto9a or MLL-AF9 oncofusion -proteins. Transduced Gfi1b heterozygous or Gfi1b deficient cells generated more colonies and higher cell number than wt transduced cells. We also used mice transgenically expressing CBFbeta-Myh11. Deletion of Gfi1b accelerated leukemia formation in these mice compared to mice in which Gfi1b was still expressed. On a molecular level, we found that loss of Gfi1b leads to increased levels of ROS level. It has been shown by other groups, that increased levels of Gfi1b contribute to leukemia development. In addition, Gfi1b represses the expression of Integrin beta 3 (ITGB3). Absence of Gfi1b leads to higher expression level of ITGB3. ITGB3 has been shown to promote growth and expansion of leukemic stem cells, which play an important role in AML development. Thus we report here that Gfi1b acts as a novel tumor suppressor in AML development. Disclosures: No relevant conflicts of interest to declare.

Targeting of Acute Myeloid Leukemia by Cytokine-Induced Killer Cells Redirected with a Novel CD123-Specific Chimeric Antigen Receptor.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3010-3010 ◽  
Author(s):  
Sarah Tettamanti ◽  
Virna Marin ◽  
Irene Pizzitola ◽  
Chiara Francesca Magnani ◽  
Greta Maria Paola Giordano Attianese ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Cytotoxicity Assay ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Cik Cells ◽  
Acute Myeloid

Abstract Abstract 3010 Current therapeutic regimens for Acute Myeloid Leukemia (AML) are still associated with high rates of relapse. In the last years, great interest has been focused on the identification of surface molecules that are preferentially expressed by AML cells and leukemic stem cells (LSCs), in order to selectively target the tumor population, whilst sparing the normal counterpart of hematopoietic stem/progenitor cells (HSPC), and possibly impeding disease recurrence. Immunotherapy with T-cells genetically modified to express chimeric antigen receptors (CARs) represents a valid and innovative cell therapy approach for hematological malignancies. In this study we developed a new CAR molecule specific for the IL-3Rα (CD123) target antigen, which is overexpressed on AML blasts, CD34+ leukemic progenitors, and leukemic stem cells (AML-LSCs) compared to normal hematopoietic stem/progenitor cells (HSPCs), and whose overexpression is associated with poor prognosis. Cytokine Induced Killer (CIK) cells, ex-vivo expanded T cells with spontaneous antitumoral activity, were transduced with an SFG-retroviral vector encoding an anti-CD123.CAR and CAR functionality has been evaluated by short-term cytotoxicity assay. Transduced CIK cells strongly killed CD123+ THP-1 cell line (60%±5.4%, Effector:Target –E:T- ratio of 5:1, n=3), as well as primary AML blasts (59%±5.4%, E:T ratio of 3:1, n=4). With the aim to better characterize the ability of anti-CD123.CAR+CIK cells to kill leukaemia cells over time we performed long-term cytotoxicity assay, observing a leukemic cell recovery for THP-1 of 3.5%±1.5% (n=5) and for primary AML cells of 2.4%±1.4% (n=3) when co-cultured with CIK cells expressing anti-CD123.CAR, compared to an average target survival of up to 80%, when co-cultured with unmanipulated (NT) CIK cells. Interestingly, secondary colonies experiments after co-culture of healthy donor cord blood-derived HSPCs (Lin-) with anti-CD123.CAR+CIK cells demonstrated that this newly generated CAR molecule better preserved the normal haematopoietic reconstitution in contrast to a previously generated anti-CD33.CAR (total number of colonies of 146.8±6.6, 66.4±5.1, 117.6±4.6, for Lin- cells co-cultured with NT CIK cells, anti-CD33.CAR+CIK cells, anti-CD123.CAR+CIK cells respectively, n=4), while keeping identical cytotoxicity profile towards AML. Furthermore, a limited killing of normal CD123 expressing monocytes and CD123-low expressing endothelial cells was measured, accompanied by a lesser release of stimulatory cytokines such as IFN-gamma, TNF-alfa and TNF-beta when compared to the levels released after stimulation with CD123+ leukemic cells (THP-1 and AML), thus indicating a low toxicity profile of the anti-CD123.CAR. Taken together, our results indicate that CD123-specific CAR strongly enhances anti-leukemic CIK functions towards AML, while sparing HSPCs and normal CD123-expressing tissues, paving the way for the development of novel immunotherapy approaches for the treatment of resistant forms of AML, particularly for a precocious intervention in presence of minimal residual disease, in the context of early relapse after HSCT. Disclosures: No relevant conflicts of interest to declare.

scholarly journals CD9, a potential leukemia stem cell marker, regulates drug resistance and leukemia development in acute myeloid leukemia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yongliang Liu ◽  
Guiqin Wang ◽  
Jiasi Zhang ◽  
Xue Chen ◽  
Huailong Xu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Drug Resistance ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Stem Cell Marker ◽  
Hematopoietic Stem ◽  
Chemotherapy Drugs ◽  
And Migration ◽  
Acute Myeloid

Abstract Background Leukemia stem cells (LSCs) are responsible for the initiation, progression, and relapse of acute myeloid leukemia (AML). Therefore, a therapeutic strategy targeting LSCs is a potential approach to eradicate AML. In this study, we aimed to identify LSC-specific surface markers and uncover the underlying mechanism of AML LSCs. Methods Microarray gene expression data were used to investigate candidate AML-LSC-specific markers. CD9 expression in AML cell lines, patients with AML, and normal donors was evaluated by flow cytometry (FC). The biological characteristics of CD9-positive (CD9+) cells were analyzed by in vitro proliferation, chemotherapeutic drug resistance, migration, and in vivo xenotransplantation assays. The molecular mechanism involved in CD9+ cell function was investigated by gene expression profiling. The effects of alpha-2-macroglobulin (A2M) on CD9+ cells were analyzed with regard to proliferation, drug resistance, and migration. Results CD9, a cell surface protein, was specifically expressed on AML LSCs but barely detected on normal hematopoietic stem cells (HSCs). CD9+ cells exhibit more resistance to chemotherapy drugs and higher migration potential than do CD9-negative (CD9−) cells. More importantly, CD9+ cells possess the ability to reconstitute human AML in immunocompromised mice and promote leukemia growth, suggesting that CD9+ cells define the LSC population. Furthermore, we identified that A2M plays a crucial role in maintaining CD9+ LSC stemness. Knockdown of A2M impairs drug resistance and migration of CD9+ cells. Conclusion Our findings suggest that CD9 is a new biomarker of AML LSCs and is a promising therapeutic target.

scholarly journals Evidence for malignant transformation in acute myeloid leukemia at the level of early hematopoietic stem cells by cytogenetic analysis of CD34+ subpopulations

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 2906-2912 ◽  
Author(s):  
D Haase ◽  
M Feuring-Buske ◽  
S Konemann ◽  
C Fonatsch ◽  
C Troff ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Malignant Transformation ◽  
Cell Sorting ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Leukemic Cells ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a heterogenous disease according to morphology, immunophenotype, and genetics. The retained capacity of differentiation is the basis for the phenotypic classification of the bulk population of leukemic blasts and the identification of distinct subpopulations. Within the hierarchy of hematopoietic development and differentiation it is still unknown at which stage the malignant transformation occurs. It was our aim to analyze the potential involvement of cells with the immunophenotype of pluripotent stem cells in the leukemic process by the use of cytogenetic and cell sorting techniques. Cytogenetic analyses of bone marrow aspirates were performed in 13 patients with AML (11 de novo and 2 secondary) and showed karyotype abnormalities in 10 cases [2q+, +4, 6p, t(6:9), 7, +8 in 1 patient each and inv(16) in 4 patients each]. Aliquots of the samples were fractionated by fluorescence-activated cell sorting of CD34+ cells. Two subpopulations, CD34+/CD38-(early hematopoietic stem cells) and CD34+/CD38+ (more mature progenitor cells), were screened for karyotype aberations as a marker for leukemic cells. Clonal abnormalities and evaluable metaphases were found in 8 highly purified CD34+/CD38-populations and in 9 of the CD34+/CD38-specimens, respectively. In the majority of cases (CD34+/CD38-, 6 of 8 informative samples; CD34+/CD38+, 5 of 9 informative samples), the highly purified CD34+ specimens also contained cytogenetically normal cells. Secondary, progression-associated chromosomal changes (+8, 12) were identified in the CD34+/CD38-cells of 2 patients. We conclude that clonal karyotypic abnormalities are frequently found in the stem cell-like (CD34+/CD38-) and more mature (CD34+/CD38+) populations of patients with AML, irrespective of the phenotype of the bulk population of leukemic blasts and of the primary or secondary character of the leukemia. Our data suggest that, in AML, malignant transformation as well as disease progression may occur at the level of CD34+/CD38-cells with multilineage potential.

scholarly journals 7-Ketocholesterol Promotes Oxiapoptophagy in Bone Marrow Mesenchymal Stem Cell from Patients with Acute Myeloid Leukemia

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 482 ◽  
Author(s):  
Jessica Liliane Paz ◽  
Debora Levy ◽  
Beatriz Araujo Oliveira ◽  
Thatiana Correia de Melo ◽  
Fabio Alessandro de Freitas ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cholesterol Oxidation ◽  
Specific Cell ◽  
Hematopoietic Stem ◽  
Shh Pathway ◽  
Number Of Cells ◽  
Acute Myeloid

7-Ketocholesterol (7-KC) is a cholesterol oxidation product with several biological functions. 7-KC has the capacity to cause cell death depending on the concentration and specific cell type. Mesenchymal stem cells (MSCs) are multipotent cells with the ability to differentiate into various types of cells, such as osteoblasts and adipocytes, among others. MSCs contribute to the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases, such as leukemia, to a yet unknown extent. Here, we describe the effect of 7-KC on the death of bone marrow MSCs from patients with acute myeloid leukemia (LMSCs). LMSCs were less susceptible to the death-promoting effect of 7-KC than other cell types. 7-KC exposure triggered the extrinsic pathway of apoptosis with an increase in activated caspase-8 and caspase-3 activity. Mechanisms other than caspase-dependent pathways were involved. 7-KC increased ROS generation by LMSCs, which was related to decreased cell viability. 7-KC also led to disruption of the cytoskeleton of LMSCs, increased the number of cells in S phase, and decreased the number of cells in the G1/S transition. Autophagosome accumulation was also observed. 7-KC downregulated the SHh protein in LMSCs but did not change the expression of SMO. In conclusion, oxiapoptophagy (OXIdative stress + APOPTOsis + autophagy) seems to be activated by 7-KC in LMSCs. More studies are needed to better understand the role of 7-KC in the death of LMSCs and the possible effects on the SHh pathway.

scholarly journals Gpr44 Mediates the Selenium-Dependent Anti-Leukemic Effect in Acute Myeloid Leukemia

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1835-1835
Author(s):  
Fenghua Qian ◽  
Fenghua Qian ◽  
Diwakar Tukaramrao ◽  
Jiayan Zhou ◽  
Nicole Palmiero ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Murine Model ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Pparγ Agonist ◽  
Acute Myeloid

Abstract Objectives The relapse of acute myeloid leukemia (AML) remains a significant concern due to persistent leukemia stem cells (LSCs) that are not targeted by existing therapies. LSCs show sensitivity to endogenous cyclopentenone prostaglandin J (CyPG) metabolites that are increased by dietary trace element selenium (Se), which is significantly decreased in AML patients. We investigated the anti-leukemic effect of Se supplementation in AML via mechanisms involving the activation of the membrane-bound G-protein coupled receptor 44 (Gpr44) and the intracellular receptor, peroxisome proliferator-activated receptor gamma (PPARγ), by endogenous CyPGs. Methods A murine model of AML generated by transplantation of hematopoietic stem cells (HSCs- WT or Gpr44−/−) expressing human MLL-AF9 fusion oncoprotein, in the following experiments: To investigate the effect of Se supplementation on the outcome of AML, donor mice were maintained on either Se-adequate (Se-A; 0.08–0.1 ppm Se) or Se-supplemented (Se-S; 0.4 ppm Se) diets. Complete cell counts in peripheral blood were analyzed by hemavet. LSCs in bone marrow and spleen were analyzed by flow cytometry. To determine the role of Gpr44 activation in AML, mice were treated with Gpr44 agonists, CyPGs. LSCs in bone marrow and spleen were analyzed. Mice transplanted with Gpr44−/- AML cells were compared with mice transplanted with wild type AML cells and the progression of the disease was followed as above. To determine the role of PPARγ activation in AML, PPARγ agonist (Rosiglitazone, 6 mg/kg, i.p, 14 d) and antagonist (GW9662, 1 mg/kg, i.p. once every other day, 7 injections) were applied to Se-S mice transplanted with Gpr44−/- AML cells and disease progression was followed. Results Se supplementation at supraphysiological levels alleviated the disease via the elimination of LSCs in a murine model of AML. CyPGs induced by Se supplementation mediate the apoptosis in LSCs via the activation of Gpr44 and PPARγ. Conclusions Endogenous CyPGs produced upon supplementation with Se at supraphysiological levels improved the outcome of AML by targeting LSCs to apoptosis via the activation of two receptors, Gpr44 and PPARg. Funding Sources NIH DK 07,7152; CA 175,576; CA 162,665. Office of Dietary Supplements, USDA Hatch funds PEN04605, Accession # 1,010,021 (KSP, RFP).

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