The role of aldehyde dehydrogenase (ALDH) isoform 1A3 in the pathogenesis of human acute myeloid leukemia (AML)

2011 ◽  
Author(s):  
Chiu-yin So
Keyword(s):  
Acute Myeloid Leukemia ◽  
Aldehyde Dehydrogenase ◽  
Myeloid Leukemia ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

scholarly journals Disruption of SIRPα signaling in macrophages eliminates human acute myeloid leukemia stem cells in xenografts

2012 ◽  
Vol 209 (10) ◽  
pp. 1883-1899 ◽  
Author(s):  
Alexandre P.A. Theocharides ◽  
Liqing Jin ◽  
Po-Yan Cheng ◽  
Tatiana K. Prasolava ◽  
Andrei V. Malko ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cell Function ◽  
Leukemia Stem Cell ◽  
Tumor Surveillance ◽  
Human Acute Myeloid Leukemia ◽  
Differential Ability ◽  
Acute Myeloid

Although tumor surveillance by T and B lymphocytes is well studied, the role of innate immune cells, in particular macrophages, is less clear. Moreover, the existence of subclonal genetic and functional diversity in some human cancers such as leukemia underscores the importance of defining tumor surveillance mechanisms that effectively target the disease-sustaining cancer stem cells in addition to bulk cells. In this study, we report that leukemia stem cell function in xenotransplant models of acute myeloid leukemia (AML) depends on SIRPα-mediated inhibition of macrophages through engagement with its ligand CD47. We generated mice expressing SIRPα variants with differential ability to bind human CD47 and demonstrated that macrophage-mediated phagocytosis and clearance of AML stem cells depend on absent SIRPα signaling. We obtained independent confirmation of the genetic restriction observed in our mouse models by using SIRPα-Fc fusion protein to disrupt SIRPα–CD47 engagement. Treatment with SIRPα-Fc enhanced phagocytosis of AML cells by both mouse and human macrophages and impaired leukemic engraftment in mice. Importantly, SIRPα-Fc treatment did not significantly enhance phagocytosis of normal hematopoietic targets. These findings support the development of therapeutics that antagonize SIRPα signaling to enhance macrophage-mediated elimination of AML.

The Role of Monocytes in Phagocytosis and Mixed Leukocyte Reactivity in Human Acute Myeloid Leukemia

1979 ◽  
Vol 8 (3) ◽  
pp. 279-301 ◽  
Author(s):  
Thomas D. Miale ◽  
Leif Å. L. Stenke ◽  
Marta Penchansky ◽  
Toini Lehtinen ◽  
Peter G. Reizenstein
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

Rethinking the role of osteopontin in human acute myeloid leukemia

2016 ◽  
Vol 58 (6) ◽  
pp. 1494-1497 ◽  
Author(s):  
Annette K. Brenner ◽  
Elise Aasebø ◽  
Maria Hernandez-Valladares ◽  
Frode Selheim ◽  
Frode Berven ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

MicroRNA Profiling of Human Acute Myeloid Leukemia and Normal Hematopoietic Stem/Progenitor Cells Reveals a Leukemia Stem Cell Signature.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 779-779
Author(s):  
Christopher Y. Park ◽  
Yulei Wang ◽  
Susan Prohaska ◽  
Diane Tseng ◽  
Irving L. Weissman
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Supervised Clustering ◽  
Differentially Expressed Mirnas ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

Abstract While numerous studies have contributed important insights into the molecular origins of human acute myeloid leukemia (AML), many may not accurately reflect molecular pathways critical to AML development or maintenance because they ignore the inherent heterogeneity among AML blasts. One subset of blasts - leukemia stem cells (LSCs) - exhibits the unique ability to self-renew and to engraft disease in immunodeficient mouse hosts, suggesting that their elimination is critical to developing curative therapies. In addition, there is little information regarding the role of microRNAs (miRNAs) in regulating gene expression or biologic function in AML. In order to assess the potential contribution of miRNAs to AML LSC biology, we have evaluated the expression profile of 315 mature miRNAs in FACS-purified AML LSC and compared it to both non-LSC blasts as well as normal human bone marrow (BM) derived hematopoietic stem cells (HSC) and committed progenitors using a multiplexed TaqMan-based real-time PCR strategy. SAM analysis with stringent criteria (at least 25% samples with Ct <30, FDR <1%) reveals that AML LSC and non-LSC blasts are more similar to one another than to normal HSC or committed progenitors. Among the BM populations tested, AML LSC and non-LSC populations are most similar to the granulocyte-macrophage progenitor (GMP). A set of miRNAs distinguishes AML LSC and non-LSC from normal HSC and committed progenitors, including 35 miRNAs that are under-expressed and 33 miRNAs that are over-expressed in both AML fractions versus the normal populations; many of these differentially expressed miRNAs show a range of expression exceeding 3 orders of magnitude. Supervised clustering analysis of AML LSC and non-LSC blasts reveals an LSC signature composed of 89 miRNAs, with nearly all differentially expressed miRNAs (86/89) exhibiting lower expression levels in AML LSC than non-LSC blasts. Finally, supervised clustering identifies a “stem-cell” signature composed of 17 miRNAs that are over-expressed in AML LSC and HSC versus committed progenitors. This group of miRNAs does not include miRNAs previously described as being highly expressed in embryonic stem cells. Together, these studies represent the first direct comparison of miRNA expression in a human cancer stem cell to its normal counterpart, thereby identifying miRNAs that may regulate AML LSC and/or normal HSC/committed progenitor function. Initial functional studies in vivo using LNA knockdown strategies indicate that a subset of miRNAs highly expressed in HSC and LSC is important in regulating normal HSC function. We are currently expanding these studies to test the role of these miRNAs in maintaining engrafted AMLs in the xenotransplant setting.

Down-Regulation of Microrna 223 and 148a Mediates Resistance of Human Acute Myeloid Leukemia Cells to Pan-Histone Deacetylase (HDAC) Inhibitors.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2401-2401
Author(s):  
Jianguang Chen ◽  
Veena Kandaswamy ◽  
Warren Fiskus ◽  
Yongchao Wang ◽  
Rekha Rao ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Histone Deacetylase ◽  
Myeloid Leukemia ◽  
Hdac Inhibitors ◽  
Ectopic Expression ◽  
K562 Cells ◽  
Methyl Transferase ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

Abstract Abstract 2401 Poster Board II-378 MicroRNA (miR) alterations are highly involved in the pathogenesis of leukemia. However, the role of miRs in de novo or acquired resistance of cancer cells to therapeutic agents has not been fully elucidated. Recently, we reported the isolation and characterization of HL-60/LR cells, derived from human acute myeloid leukemia HL-60 cells, that are resistant to pan-histone deacetylase (HDAC) inhibitors (HDIs), including vorinostat and panobinostat (Blood. 2008; 112: 2896). To explore the role of miRs in acquiring resistance to HDIs, we performed a miR microarray analysis of the parental HL-60 and HL-60/LR cells. Compared to HL-60 cells, expression of thirteen microRNAs were discovered to be significantly increased (> 4-fold) and fourteen miRs were markedly down-regulated (> 4-fold) in HL-60/LR cells. Alterations in the expression of three of the most promising upregulated (miR-21, miR-126 and miR-146a) and down-regulated (miR-223, miR-148a and miR-342) miRs were confirmed by Q-PCR in HL-60/LR cells. The expression of miR-223, miR-148a and miR-342 was also significant lower in the relatively HDI-resistant K562 cells as compared to HDI-sensitive U937 and HL-60 cells. Conversely, miR-126 and miR-146a expressions were higher in K562 cells compared to U937 and HL-60 cells. Short term (24 hours) treatment with panobinostat (10 to 50 nM) did not alter the expression of miR-223 or miR-148a expression in HL-60 cells. As compared to treatment with either agent alone, co-treatment with the histone methyl transferase EZH2 antagonist 3-deazaneplanocin (DZnep, 1.0 uM) and DNA methyl transferase inhibitor decitabine (2.0 uM) induced miR-223 and miR-148a levels and mediated apoptosis of HL-60/LR cells, suggesting that an epigenetic silencing mechanism(s) may be involved in the down-modulation of miR-223 and miR-148a in HL-60/LR cells. To determine whether the alterations in the miR levels were mechanistically involved in conferring resistance to HDIs, we engineered through retroviral transduction stable ectopic expressions of miR-223, miR-148a and miR-342 into HL-60/LR cells and miR-21 and miR-146a into HL-60 cells. Ectopic expression of miR-223 and miR-148a significantly increased the sensitivity of HL-60/LR cells to panobinostat and vorinostat. In contrast, re-expression of miR-342 had an insignificant effect on HDI sensitivity. Increased expression of miR-21 and miR-146a did not confer resistance to the HDIs in HL-60 and U937 cells. Next, by Western analyses, we compared the expression levels of several of the predicted target proteins of miR-223 and miR-148a, (as predicted by the computer programs TargetScan and picTAR), in HL-60 versus HL-60/LR cells, as well as in the HL-60/LR cells with stable ectopic expression of miR-223 and miR-148a. Several candidate proteins including GRP94, Ribosomal protein S6 kinase MSK1, MEF2C and DNMT1 showed higher level of expression in HL-60/LR versus HL-60 and were down-regulated in miR-223 or miR-148a transduced HL-60/LR cells, suggesting that these proteins may confer resistance against HDI. Parenthetically, miR-223 was shown to be a myeloid-specific miR which negatively regulates progenitor proliferation and granulocyte differentiation and activation. miR-223 mutant mice have an expanded granulocytic compartment resulting from an increase in the number of granulocyte progenitors. In summary, our observations indicate that high miR-223 and miR-148a levels may be predictive biomarkers for sensitivity to HDIs in human AML cells. Additionally, induction of miR-223 and miR-148a by EZH2 antagonist may increase sensitivity and overcome resistance to HDIs in human AML cells. Targeting the levels and/or activity of the miR-223 and miR-148a target proteins may also be an effective strategy in enhancing the activity of HDI based combination therapy against AML. Disclosures: Atajada: Novartis: Employment. Bhalla:Merck: Honoraria; Novartis: Honoraria, Research Funding.

Role of FLT3 gene mutations in acute myeloid leukemia: effect on course of disease and results of therapy

2019 ◽  
Vol XIV (1) ◽  
Author(s):  
A.M. Radzhabova ◽  
S.V. Voloshin ◽  
I.S. Martynkevich ◽  
A.A. Kuzyaeva ◽  
V.A. Shuvaev ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Course Of Disease ◽  
Acute Myeloid
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