Targeting Acute Myeloid Leukemia Stem Cells by MUC1-C Subunit Inhibition

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 848-848 ◽  
Author(s):  
Dina Stroopinsky ◽  
Jacalyn Rosenblatt ◽  
Keisuke Ito ◽  
Li Yin ◽  
Hasan Rajabi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Colony Formation ◽  
Myeloid Leukemia ◽  
Muc1 Expression ◽  
Hematopoietic Stem ◽  
Flow Cytometric ◽  
Control Peptide ◽  
Cd34 Cells ◽  
Acute Myeloid

Abstract Abstract 848 Introduction: Acute myeloid leukemia (AML) arises from a malignant stem cell population that is resistant to cytotoxic therapy and represents a critical reservoir of conferring disease recurrence. A major focus of investigation is the identification of unique markers on leukemia stem cells (LSCs) that differentiate them from normal hematopoietic stem cells and thereby serve as potential therapeutic targets. MUC1 is a high molecular weight transmembrane glycoprotein that is aberrantly expressed in many epithelial tumors and confers cell growth and survival. We have developed an inhibitor of the MUC1-C receptor subunit that blocks oligomer formation and nuclear localization. In the present study, we have examined expression of MUC1 on LSCs as compared to normal hematopoietic stem cells and studied the effect of MUC1-C inhibition on the functional properties of LSCs. Methods and Results: Using multichannel flow cytometric analysis, we isolated the LSC compartment as defined by CD34+/CD38-/lineage- cells from bone marrow specimens obtained from patients with active AML. The majority of LSCs strongly expressed MUC1 with a mean percentage of 77% (n=6). These findings were confirmed by immunocytochemical staining of LSCs isolated by flow cytometric sorting. MUC1 expression was not detectable on the CD34- fraction of AML cells, but was present on the granulocyte-macrophage progenitor (GMP) fraction (CD34+/CD38+ cells) (mean=83%; n=6). In contrast, MUC1 expression was not observed on CD34+ progenitors isolated from normal donors (18%, n=6). In concert with these findings, RT-PCR analysis for MUC1 RNA demonstrated expression in CD34+ cells isolated from AML patients, but not normal volunteers. Notably, we also found that MUC1 expression selectively identifies malignant hematopoietic progenitors in a patient with chimerism between normal and leukemia derived stem cells. The presence of MUC1+CD34+ cells was detected in a patient with AML who achieved a morphologic complete remission following sex mismatched allogeneic transplantation. Using Bioview technology, we found that MUC1 is expressed only in the recipient (XX) CD34+ cells, representing residual malignant cells, whereas the donor (XY) derived CD34+ cells, representing the majority of the progenitors, lacked MUC1 expression. We subsequently examined the effects of MUC1-C inhibition on the capacity of leukemic progenitors to proliferate and support colony formation. MUC1-C inhibition with the GO-203 cell-penetrating peptide resulted in downregulation of the β-catenin pathway, an important modulator of cell division and survival, which is known to support the LSC phenotype. No significant change was detected with a control peptide, or with MUC1-C inhibition of progenitors isolated from a normal control. Furthermore, MUC1-C inhibition resulted in apoptosis, as demonstrated by flow cytometric staining for AnnexinV in AML CD34+ cells, but not in CD34+ progenitors isolated from normal volunteers (mean Annexin positive cells 53% and 5%, respectively, n=4). Consistent with these findings, the MUC1-C inhibitor, but not the control, peptide resulted in cell death of CD34+ cells isolated from AML patients, but not normal controls. Most significantly, exposure of CD34+ AML cells to the MUC1-C inhibitor resulted in loss of their capacity for colony formation in vitro with mean colonies of 4 and 40 for those cells exposed to the MUC1 inhibitor and a control peptide (n=2). In contrast, colony formation by normal hematopoietic stem cells was unaffected. Conclusions: MUC1 is selectively expressed by leukemic progenitors and may be used to differentiate malignant from normal hematopoietic stem cell populations. MUC1-C receptor subunit inhibition results in (i) downregulation of b-catenin signaling, (ii) induction of apoptosis and cell death, and (iii) disruption of the capacity to induce leukemia colony formation. Disclosures: Stone: genzyme: Consultancy; celgene: Consultancy; novartis: Research Funding. Kufe:Genus Oncology: Consultancy, Equity Ownership.

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.

MicroRNA-29a Is An Oncogene in Acute Myeloid Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 683-683
Author(s):  
Christopher Y. Park ◽  
Yoon-Chi Han ◽  
Govind Bhagat ◽  
Jian-Bing Fan ◽  
Irving L Weissman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Mirna Expression ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Abstract microRNAs (miRNAs) are short, non-protein encoding RNAs that bind to the 3′UTR’s of target mRNAs and negatively regulate gene expression by facilitating mRNA degradation or translational inhibition. Aberrant miRNA expression is well-documented in both solid and hematopoietic malignancies, and a number of recent miRNA profiling studies have identified miRNAs associated with specific human acute myeloid leukemia (AML) cytogenetic groups as well as miRNAs that may prognosticate clinical outcomes in AML patients. Unfortunately, these studies do not directly address the functional role of miRNAs in AML. In fact, there is no direct functional evidence that miRNAs are required for AML development or maintenance. Herein, we report on our recent efforts to elucidate the role of miRNAs in AML stem cells. miRNA expression profiling of AML stem cells and their normal counterparts, hematopoietic stem cells (HSC) and committed progenitors, reveals that miR-29a is highly expressed in human hematopoietic stem cells (HSC) and human AML relative to normal committed progenitors. Ectopic expression of miR-29a in mouse HSC/progenitors is sufficient to induce a myeloproliferative disorder (MPD) that progresses to AML. During the MPD phase of the disease, miR-29a alters the composition of committed myeloid progenitors, significantly expedites cell cycle progression, and promotes proliferation of hematopoietic progenitors at the level of the multipotent progenitor (MPP). These changes are manifested pathologically by marked granulocytic and megakaryocytic hyperplasia with hepatosplenomegaly. Mice with miR-29a-induced MPD uniformly progress to an AML that contains a leukemia stem cell (LSC) population that can serially transplant disease with as few as 20 purified LSC. Gene expression analysis reveals multiple tumor suppressors and cell cycle regulators downregulated in miR-29a expressing cells compared to wild type. We have demonstrated that one of these genes, Hbp1, is a bona fide miR-29a target, but knockdown of Hbp1 in vivo does not recapitulate the miR-29a phenotype. These data indicate that additional genes are required for miR-29a’s leukemogenic activity. In summary, our data demonstrate that miR-29a regulates early events in normal hematopoiesis and promotes myeloid differentiation and expansion. Moreover, they establish that misexpression of a single miRNA is sufficient to drive leukemogenesis, suggesting that therapeutic targeting of miRNAs may be an effective means of treating myeloid leukemias.

TIM-3 Is a Promising Target to Eradicate Acute Myeloid Leukemia Stem Cells Sparing Normal Hematopoietic Stem Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 559-559
Author(s):  
Toshihiro Miyamoto ◽  
Yoshikane Kikushige ◽  
Takahiro Shima ◽  
Koichi Akashi
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Myeloid Leukemia ◽  
Leukemia Cell ◽  
Cytotoxic Activities ◽  
Antibody Treatment ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Abstract Abstract 559 Acute myeloid leukemia (AML) originates from self-renewing leukemic stem cells (LSCs), an ultimate therapeutic target for permanent cure. To selectively kill AML LSCs sparing normal hematopoietic stem cells (HSCs), one of the most practical approaches is to target the AML LSCs-specific surface or functionally indispensable molecules. Based on differential transcriptome analysis of prospectively-purified CD34+CD38− LSCs from AML patient samples and normal HSCs, we found that T-cell immunoglobulin mucin-3 (TIM-3) was highly expressed in AML LSCs but not in normal HSCs (Kikushige et al., Cell Stem Cell, 2010). In normal hematopoiesis, TIM-3 is mainly expressed in mature monocytes and a fraction of NK cells, but not in granulocytes, T cells or B cells. In the bone marrow, TIM-3 is expressed only in a fraction of granulocyte/macrophage progenitors (GMPs) at a low level, but not in HSCs, common myeloid progenitors, or megakaryocyte/erythrocyte progenitors. In contrast, in human AML, TIM-3 was expressed on cell surface of the vast majority of CD34+CD38− LSCs and CD34+CD38+ leukemic progenitors in AML of most FAB types, except for acute promyelocytic leukemia (M3). FACS-sorted TIM-3+ but not TIM-3− AML cells reconstituted human AML in the immunodeficient mice, indicating that the TIM-3+ population contains most of functional LSCs. To selectively eradicate TIM-3-expressing AML LSCs, we established an anti-human TIM-3 mouse IgG2a antibody, ATIK2a, possessing antibody-dependent cellular cytotoxic and complement-dependent cytotoxic activities in leukemia cell lines transfected with TIM-3. We first tested the effect of ATIK2a treatment on reconstitution of normal HSCs in a xenograft model. ATIK2a was intraperitoneally injected to the mice once a week after 12 hours of transplantation of human CD34+ cells. Injection of ATIK2a did not affect reconstitution of normal human hematopoiesis except removing TIM-3-expressing mature monocytes. In contrast, injection of TIM-3 to the mice transplanted with human AML samples markedly reduced leukemic repopulation. In some mice transplanted with AML bone marrow, only normal hematopoiesis was reconstituted after anti-TIM-3 antibody treatment, suggesting that the antibody selectively killed AML cells, sparing residual normal HSCs. To further test the inhibitory effect of ATIK2a on established human AML, eight weeks after transplantation of human AML cells, engraftment of human AML cells was confirmed by blood sampling and thereafter ATIK2a was injected to these mice. In all cases tested, ATIK2a treatment significantly reduced human TIM-3+ AML fraction as well as the CD34+CD38− LSCs fraction. In addition, to verify the anti-AML LSCs effect of ATIK2a treatment, human CD45+AML cells from the primary recipients were re-transplanted into secondary recipients. All mice transplanted from primary recipients treated with control IgG developed AML, whereas none of mice transplanted with cells from ATIK2a-treated primary recipients developed AML, suggesting that functional LSCs were effectively eliminated by ATIK2a treatment in primary recipients. Thus, TIM-3 is a promising surface molecule to target AML LSCs. Our experiments strongly suggest that targeting this molecule by monoclonal antibody treatment is a practical approach to eradicate human AML. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Clonal Evolution of Preleukemic Hematopoietic Stem Cells Precedes Human Acute Myeloid Leukemia

2012 ◽  
Vol 4 (149) ◽  
pp. 149ra118-149ra118 ◽  
Author(s):  
M. Jan ◽  
T. M. Snyder ◽  
M. R. Corces-Zimmerman ◽  
P. Vyas ◽  
I. L. Weissman ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Myeloid Leukemia ◽  
Clonal Evolution ◽  
Hematopoietic Stem ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

scholarly journals Self-Renewal Pathways in Acute Myeloid Leukemia Stem Cells

2020 ◽  
Author(s):  
Jonason Yang ◽  
Nunki Hassan ◽  
Sheng Xiang Franklin Chen ◽  
Jayvee Datuin ◽  
Jenny Y. Wang
Keyword(s):  
Stem Cells ◽  
Monoclonal Antibody ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Myeloid Leukemia ◽  
Leukemia Stem Cells ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Clinical Potential ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a difficult-to-treat blood cancer. A major challenge in treating patients with AML is relapse, which is caused by the persistence of leukemia stem cells (LSCs). Self-renewal is a defining property of LSCs and its deregulation is crucial for re-initiating a new leukemia after chemotherapy. Emerging therapeutic agents inhibiting aberrant self-renewal pathways, such as anti-RSPO3 monoclonal antibody discovered in our recent study, present significant clinical potential that may extend beyond the scope of leukemogenesis. In this chapter, we provide an overview of normal and malignant hematopoietic stem cells, discuss current treatments and limitations, and review key self-renewal pathways and potential therapeutic opportunities in AML.

scholarly journals Acute myeloid leukemia cells secrete microRNA-4532-containing exosomes to mediate normal hematopoiesis in hematopoietic stem cells by activating the LDOC1-dependent STAT3 signaling pathway

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Chen Zhao ◽  
Feng Du ◽  
Yang Zhao ◽  
Shanshan Wang ◽  
Ling Qi
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Signaling Pathway ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Stat3 Phosphorylation ◽  
Acute Myeloid

Abstract Background MicroRNA (miR)-containing exosomes released by acute myeloid leukemia (AML) cells can be delivered into hematopoietic progenitor cells to suppress normal hematopoiesis. Herein, our study was performed to evaluate the effect of exosomal miR-4532 secreted by AML cells on hematopoiesis of hematopoietic stem cells. Methods Firstly, differentially expressed miRs related to AML were identified using microarray analysis. Subsequently, AML cell lines were collected, and CD34+ HSCs were isolated from healthy pregnant women. Then, miR-4532 expression was measured in AML cells and AML cell-derived exosomes and CD34+ HSCs, together with evaluation of the targeting relationship between miR-4532 and LDOC1. Then, AML cells were treated with miR-4532 inhibitor, and exosomes were separated from AML cells and co-cultured with CD34+ HSCs. Gain- and loss-function approaches were employed in CD34+ HSCs. Colony-forming units (CFU) and expression of dickkopf-1 (DKK1), a hematopoietic inhibiting factor associated with pathogenesis of AML, were determined in CD34+ HSCs, as well as the extents of JAK2 and STAT3 phosphorylation and LDOC1 expression. Results miR-4532 was found to be upregulated in AML cells and AML cell-derived exosomes, while being downregulated in CD34+ HSCs. In addition, exosomes released by AML cells targeted CD34+ HSCs to decrease the expression of CFU and increase the expression of DKK1. miR-4532 was delivered into CD34+ HSCs to target LDOC1 via AML cell-released exosomes. AML cell-derived exosomes containing miR-4532 inhibitor increased CFU but reduced DKK1 in CD34+ HSCs. Inhibition of miR-4532 or JAK2, or ectopic expression of LDOC1 upregulated CFU and downregulated DKK1 expression as well as the extents of JAK2 and STAT3 phosphorylation in CD34+ HSCs. Conclusion In conclusion, AML cell-derived exosomes carrying miR-4532 repress normal HSC hematopoiesis via activation of the LDOC1-dependent STAT3 signaling pathway.

Impaired Hematopoietic Differentiation of iPSCs Derived From Patients with FPD/AML

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 767-767
Author(s):  
Masatoshi Sakurai ◽  
Hiroyoshi Kunimoto ◽  
Naohide Watanabe ◽  
Yumi Fukuchi ◽  
Ken Sadahira ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Pluripotent Stem Cells ◽  
Myeloid Leukemia ◽  
Hematopoietic Differentiation ◽  
Hematopoietic Stem ◽  
Differentiation Capacity ◽  
Cd34 Cells ◽  
Acute Myeloid

Abstract Abstract 767 Somatic mutation of RUNX1 has been implicated in a variety of hematopoietic malignancies including myelodysplastic syndrome and acute myeloid leukemia, and previous studies using mouse models disclosed its critical roles in hematopoiesis. During embryonic development, Runx1 is absolutely essential in the emergence of hematopoietic stem and progenitor cells through hemogenic endothelium. In contrast, conditional disruption of Runx1 in adult hematopoietic system revealed that it was critical in the differentiation of megakaryocytes and lymphocytes as well as in the function of hematopoietic stem cells (HSCs). However, these results were derived from gene-disruption studies in mouse models, and the role of RUNX1 in human hematopoiesis has never been tested in experimental settings. Familial platelet disorder/ acute myeloid leukemia (FPD/AML) is a rare autosomal dominant disorder caused by germline mutation of RUNX1, marked by thrombocytopenia and propensity to acute leukemia. To investigate the physiological function of RUNX1 in human hematopoiesis and the pathophysiology of FPD/AML, we derived induced pluripotent stem cells (iPSCs) from three distinct FPD/AML pedigrees (FPD-iPSCs) and examined their defects in hematopoietic differentiation. These pedigrees have distinct heterozygous mutations in RUNX1 gene, two in the N-terminal RUNT domain affecting its DNA-binding activity and one in the C-terminal region affecting its transactivation capacity. After obtaining informed consent from the affected patients, we established iPSCs from their peripheral T cells by infecting Sendai viruses expressing four reprogramming factors (OCT3/4, SOX2, KLF4 and c-MYC). FPD-iPSCs could be established in comparable frequency as the one from normal individuals (WT-iPSCs). Initial characterization of FPD-iPSCs revealed that the established clones retained typical characteristics of pluripotent stem cells such as the expression of Nanog, Oct3/4, SSEA-3, SSEA-4, Tra-1-60 or Tra-1-81, and the teratoma formation in immunodeficient mice. Next we examined the hematopoietic differentiation capacity of FPD-iPSCs by co-culturing on AGMS-3 cells, a stromal cell line established from aorta-gonad-mesonephros (AGM) region. FPD-iPSCs and WT-iPSCs were dispersed and plated on inactivated AGM-S3 cells and were co-cultured in the presence of vascular endothelial growth factor. On day 10 through day 14 of co-culture, cells were collected and analyzed for the emergence of hematopoietic progenitors (HPCs) by flow cytometry. Interestingly, FPD-iPSCs generated CD34+ cells or CD45+ cells in significantly lower frequencies as compared to WT-iPSCs. To evaluate the differentiation capacity of HPCs generated from iPSCs, CD34+ cells were sorted by flow cytometry and subjected to colony forming assays. This revealed that CD34+ cells derived from FPD-iPSCs generated significantly fewer colonies as compared to those from WT-iPSCs in all colony types examined, showing that differentiation capacity of HPCs were impaired by RUNX1 mutation. Furthermore, CD34+ cells from FPD-iPSCs generated CD41a+CD42b+ megakaryocytes (MgK) in significantly lower frequencies as compared to WT in in vitro liquid culture with stem cell factor (SCF) and thrombopoietin (TPO). Of note, MgKs differentiated from FPD-iPSCs are smaller in size as evidenced by mean-FSC by flow cytometry. These results indicate that differentiation of MgKs is impaired both quantitatively and qualitatively. Importantly, all three FPD-iPSC lines share the same phenotype in the above-described assays, suggesting that N-terminal and C-terminal RUNX1 mutations impose similar defects in hematopoietic differentiation of FPD-iPSCs. Taken together, this study, for the first time, demonstrated that mutation of RUNX1 leads to the defective differentiation of hematopoietic cells in human settings. The phenotype observed in this study, at least in part, recapitulates the ones previously reported in Runx1-homozygously deficient mice, suggesting that the mutations of RUNX1 seen in FPD/AML indeed act in dominant negative manner. Disclosures: No relevant conflicts of interest to declare.

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