Critical Roles Of The IDH2 Mutation In Development and Maintenance Of Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 225-225
Author(s):  
Yoko Ogawara ◽  
Takuo Katsumoto ◽  
Yukiko Aikawa ◽  
Yutaka Shima ◽  
Yuki Kagiyama ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Growth And Survival ◽  
Genes Encoding ◽  
Idh2 Mutation ◽  
Acute Myeloid

Abstract Mutations in genes encoding isocitrate dehydrogenase (IDH) 1 and 2 are frequently observed in numerous cancers including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) and angioimmunoblastic t-cell lymphoma (AITL). The roles of mutant IDHs in tumorigenesis remain unclear because of a lack of appropriate cancer models. Here we established a mouse AML model harboring an IDH2 mutation. IDH1/2 mutations in AML frequently occur simultaneously with mutations in other genes such as NPM, DNMT3A, and FLT3. In accordance with these observations, IDH2/R140Q, NPMc, DNMT3A/R882H and FLT3/ITD cooperatively induced AML in the mouse model. When only three out of the four mutant genes were transduced, the onset of AML was delayed in any combinations. These results clearly indicate that all four mutations are necessary for the efficient induction of AML. Gene-expression analysis indicated that IDH2/R140Q and NPMc cooperatively activate Hoxa9/Meis1 and hypoxia pathways to maintain AML cells in vivo. These two pathways are likely to be important for the IDH2/R140Q-mediated engraftment/survival of NPMc+ cells in mice. DNMT3A/R882H further upregulated the expression levels of Meis1. Furthermore, DNMT3A/R882H promoted the maintenance of cells in an undifferentiated state. Previous studies have shown that FLT3/ITD promotes cell growth and survival. Taken together, our results suggest that multiple signaling pathways are activated in this IDH-mediated AML system. The tumor-associated mutant IDHs catalyze the formation of an oncometabolite 2-hydroxyglutarate (2-HG), which dysregulates a set of α-ketoglutarate-dependent dioxygenases that includes epigenetic regulators (TETs and KDM4A), hypoxic signaling molecule (EGLN) and others (collagen prolyl 4-hydroxylases). Because mutant IDHs act via a mechanism that is completely different from those of previously described oncogenes, it has attracted increasing attention as a new therapeutic target. Small molecules that potently and selectively inhibit the mutant IDHs induced differentiation of cancer cells in vitro. However, it remains unclear whether the mutant IDHs are valid targets for cancer therapy in vivo. Here we report that AML harboring IDH2/R140Q can be blocked by conditional deletion of IDH2/R140Q, even after leukemia has developed. Deletion of IDH2/R140Q blocked 2-HG production and the maintenance of Csf-1r+ and c-Kit+ leukemia stem cells, resulting in survival of the AML mice. These results indicate that the IDH2 mutation is critical for the development and maintenance of AML stem cells, and that mutant IDHs are promising targets for anticancer therapy. Disclosures: No relevant conflicts of interest to declare.

The Mechanisms of Synergistically Cytotoxicity Induced by Homoharringtonine and Aclarubicin in Acute Myeloid Leukemia Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4313-4313
Author(s):  
Lei Wang ◽  
Jie Jin
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Akt Pathway ◽  
Apparent Difference ◽  
Akt Inhibitor ◽  
Simultaneous Exposure ◽  
Acute Myeloid

Abstract Abstract 4313 Previous studies showed HAA regime [HHT (homoharringtonine), cytarabine and ACR (aclarubicin)] resulted in a high complete remission (CR) rate and a better overall survival (OS) rate in patients with primary acute myeloid leukemia. To confirm if a synergistically cytotoxicity was found in AML cells, we investigated the antitumor effect relationship of HHT and ACR against AML cells. Using in vitro system, we demonstrated that simultaneous exposure to HHT and ACR resulted in strong synergistic anti-proliferative effect and apoptosis inducing in AML cells. In vivo, combination of HHT and ACR may be result in a favorable survival in AML xenograft mice. The assay of microarray gene expressing profiling highlighted apparent difference in expression of PI3K gene and WNT3a gene between cells treated by HHT and cells exposure to ACR. Furthermore, decreased expression of PI3K110 and P-AKT protein were observed in AML cells treated with HHT for 3h while no significant change in the expression of two proteins was observed in 90nM of ACR-treated cells. Western Blot analysis also showed ACR could obviously inhibit WNT3a and β-catenin protein levels in AML cells after 3 hours exposure. Although HHT could not inhibit WNT3a protein, it also could apparently down-regulate expression of β-catenin in AML cells. Simultaneous decrease of PI3K signal and WNT3a signal was induced by the combination of HHT and ACR in AML cell lines and primary AML cells. To explore possible targets of synergistically cytotoxity induced by combined HHT/ACR, we silenced wnt3a expression by RNA interference. Then we found suppression of wnt3a expression could enhance the cytotoxity of HHT and AKT inhibitor. Moreover, combining ACR with AKT inhibitor resulted in a synergistically cytotoxic effect too. β-catenin is a shared molecular in both AKT pathway and WNT pathway. Up-regulating of β-catenin expression failed to reduce cell apoptosis induced by HHT plus ACR while partially decrease the growth inhibition rate caused by combining treatment. β-catenin is required for the self-renewal of AML-LSC. Our study also suggests that combining HHT and ACR may synergistically induce apoptosis in LSC-enriched cells. These results indicate that simultaneously inhibiting activity of PI3K/AKT pathway and WNT/β-catenin pathway is a possible mechanism of synergistically cytotoxity induced combinated HHT/ACR in AML cells. Disclosures: No relevant conflicts of interest to declare.

The BTK Inhibitor Ibrutinib Blocks SDF1/CXCR4 Mediated Migration of Acute Myeloid Leukemia Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 915-915
Author(s):  
Stuart A Rushworth ◽  
Lyubov Zaitseva ◽  
Megan Y Murray ◽  
Matthew J Lawes ◽  
David J MacEwan ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Lymphocytic Leukemia ◽  
Cell Trafficking ◽  
Acute Myeloid

Abstract Introduction Despite recent significant progress in the understanding of the biology of acute myeloid leukemia (AML) the clinical outcomes for the majority of patients diagnosed with AML presently remain poor. Consequently, there is an urgent need to identify pharmacological strategies in AML, which are not only effective but can be tolerated by the older, less well patient. Recently our group and others have shown that there is high Bruton’s Tyrosine Kinase (BTK) phosphorylation and RNA expression in AML. Moreover, our recent study described for the first time that ibrutinib and BTK-targeted RNA interference reduced factor-induced proliferation of both AML cell lines and primary AML blasts, as well as reducing AML blast adhesion to bone marrow stromal cells. Inhibition of BTK has been shown to regulate chronic lymphocytic leukemia, mantle cell lymphoma and multiple myeloma cell migration by inhibiting SDF1 (stromal derived factor 1) induced CXCR4 regulated cell trafficking. Here we report that in human AML ibrutinib in addition functions in a similar way to inhibit SDF1/CXCR4-mediated AML migration at concentrations achievable in vivo. Methods To investigate the role of BTK in regulating AML migration we used both pharmacological inhibitor ibrutinib and genetic knockdown using a lentivirus mediated BTK targeted miRNA in primary AML blasts and AML cell lines. We examined migration of AML blasts and AML cells to SDF-1 using Transwell permeable plates with 8.0µM pores. Western blotting was used to examine the role of SDF-1 in regulating BTK, AKT and MAPK activation in primary AML blasts. Results We initially examined the expression of CXCR4 in human AML cell lines and found that 4/4 cell lines were positive for CXCR4 expression. Next we examined the effects of ibrutinib on the migration of the AML cell lines U937, MV4-11, HL60 and THP-1 in response to SDF1. We found that ibrutinib can inhibit the migration of all AML cell lines tested. We tested the in-vitro activity of ibrutinib on SDF-1 induced migration in a spectrum of primary AML blasts from a wide age spectrum of adult patients and across a range of WHO AML subclasses and found that ibrutinib significantly inhibits primary AML blast migration (n=12). Next we found that ibrutinib can inhibit SDF-1 induced BTK phosphorylation and downstream MAPK and AKT signalling in primary AML blast. Finally to eliminate the problems associated with off target ibrutinib activity we evaluated migration of AML cells lines using genetic inhibition of BTK. The introduction of BTK-specific miRNA dramatically inhibited the expression of BTK in THP-1 and HL60 and reduced SDF1 mediated migration confirming that BTK is involved in regulating AML migration in response to SDF1. Conclusions These results reported here provide a molecular mechanistic rationale for clinically evaluating BTK inhibition in AML patients and suggests that in some AML patients the blasts count may initially rise in response to ibrutinib therapy, analgous to similar clinical observations in CLL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Gab2 deficiency prevents Flt3-ITD driven acute myeloid leukemia in vivo

Leukemia ◽  
2021 ◽  
Author(s):  
Corinna Spohr ◽  
Teresa Poggio ◽  
Geoffroy Andrieux ◽  
Katharina Schönberger ◽  
Nina Cabezas-Wallscheid ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Tyrosine Kinases ◽  
Myeloid Leukemia ◽  
Downstream Effector ◽  
Flt3 Inhibitor ◽  
Genes Encoding ◽  
Deficient Mice ◽  
Acute Myeloid

AbstractInternal tandem duplications (ITD) of the FMS-like tyrosine kinase 3 (FLT3) predict poor prognosis in acute myeloid leukemia (AML) and often co-exist with inactivating DNMT3A mutations. In vitro studies implicated Grb2-associated binder 2 (GAB2) as FLT3-ITD effector. Utilizing a Flt3-ITD knock-in, Dnmt3a haploinsufficient mouse model, we demonstrate that Gab2 is essential for the development of Flt3-ITD driven AML in vivo, as Gab2 deficient mice displayed prolonged survival, presented with attenuated liver and spleen pathology and reduced blast counts. Furthermore, leukemic bone marrow from Gab2 deficient mice exhibited reduced colony-forming unit capacity and increased FLT3 inhibitor sensitivity. Using transcriptomics, we identify the genes encoding for Axl and the Ret co-receptor Gfra2 as targets of the Flt3-ITD/Gab2/Stat5 axis. We propose a pathomechanism in which Gab2 increases signaling of these receptors by inducing their expression and by serving as downstream effector. Thereby, Gab2 promotes AML aggressiveness and drug resistance as it incorporates these receptor tyrosine kinases into the Flt3-ITD signaling network. Consequently, our data identify GAB2 as a promising biomarker and therapeutic target in human AML.

SRPK1 Is a Therapeutic Vulnerability in Acute Myeloid Leukemia through Its Effects on Alternative Isoforms of Epigenetic Regulators Including BRD4

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 781-781
Author(s):  
Konstantinos Tzelepis ◽  
Etienne De Braekeleer ◽  
Isaia Barbieri ◽  
Vijay Baskar ◽  
Demetrios Aspris ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Fusion Gene ◽  
Ectopic Expression ◽  
Pharmacological Inhibition ◽  
Epigenetic Regulators ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is an aggressive cancer with a poor prognosis, for which the therapeutic landscape has changed little for decades. Aberrant mRNA splicing plays an important role in cancer development and genes coding for several of the major components of the spliceosome are targeted by somatic mutations in several cancers including myelodysplastic syndromes and AML. Recently, myeloid neoplasms harbouring spliceosome gene mutations were shown to be preferentially susceptible to pharmacological disruption of the spliceosome. Here we report that targeting particular pathways of the spliceosome machinery can also be an effective therapeutic strategy in other types of AML. Recently, we generated a comprehensive catalogue of genetic vulnerabilities in AML using CRISPR-Cas9 genome-wide recessive screens and reported several novel intuitive and non-intuitive therapeutic candidates. Amongst these we identified SRPK1, the gene coding for a serine-threonine kinase that phosphorylates the major spliceosome protein SRSF1. Here, we demonstrate that targeted genetic disruption of SRPK1 in MLL-rearranged AMLs leads to differentiation and apoptosis (Fig. 1A). Additionally, the survival of immunocompromised mice transplanted with human AML cell lines carrying the MLL-AF9 fusion gene, namely MOLM-13 and THP-1, was significantly prolonged by genetic disruption of SRPK1 with CRISPR-Cas9. Similar effects were seen with pharmacological inhibition of SRPK1 in vitro and in vivo, using the novel SRPK1-specific kinase inhibitor SPHINX31 (Fig. 1B-C). Importantly, we go on to demonstrate that, while the SRPK1 kinase activity is required for AML cell survival, it is dispensable for normal hematopoiesis. At the molecular level, we show that genetic or pharmacological inhibition of SRPK1 was associated with widespread changes in the splicing of multiple genes including several with roles in leukemogenesis such as MYB, BRD4 and MED24 . We focused on BRD4 as its splicing isoforms have distinct molecular properties and found that SRPK1 inhibition led to a substantial switch from the short (BRD4S) to the long (BRD4L) isoform at the mRNA and protein levels (Fig. 1D-E). This was associated with BRD4 eviction from genomic loci involved in myeloid leukemogenesis including BCL2 and MYC. Notably, ectopic expression of the short (BRD4S) isoform rescued the phenotype of SRPK1 inhibition suggesting that the observed BRD4 splicing switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Furthermore, we show that the BRD inhibitor iBET-151 synergizes with SRPK1 inhibition to kill human MLL-AF9 -driven AMLs in vitro and in vivo. Collectively our findings reveal that SRPK1 is required for normal splicing of key epigenetic regulators including BRD4 and represents a novel therapeutic vulnerability in AML that can be used alone or in combination with clinically relevant epigenetic drugs to enhance their anti-leukemic effects. Disclosures No relevant conflicts of interest to declare.

Vgamma9Vdelta2 T Cells-Based Immunotherapy Targeting BTN3 Molecules in Acute Myeloid Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3726-3726
Author(s):  
Daniel Olive ◽  
Audrey Benyamine ◽  
Aude Le Roy ◽  
Rémy Castellano ◽  
Julie Gertner-Dardenne ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Mevalonate Pathway ◽  
Conflicts Of Interest ◽  
Tumor Burden ◽  
Acute Myeloid

Abstract As they can kill Acute Myeloid Leukemia (AML) blasts in vitro and in vivo, Vg9Vd2T cells are key players in the design of new strategies of immunotherapy. AminoBisphonates (NBP) can enhance their activation in vitro and in vivo. Their combination with low-dose IL2 has shown promising results in 2 patients with AML who underwent partial remission. NBP treatment of blasts inhibits the Mevalonate pathway. The subsequent accumulation of Isopentenyl Diphosphate sensitize AML blasts to Vg9Vd2T cells killing but some AML cell lines blasts are resistant to this TCR mediated-lysis. Butyrophilin 3 A1 (BTN3A1) has been shown to be involved in IPP recognition and Vg9Vd2 T cells activation. Agonist monoclonal antibodies (mAb) recognizing the 3 isoforms of BTN3, can trigger BTN3 on tumor cell lines and sensitize them to Vg9Vd2 T cells lysis. We show that primary AML blasts from patient at diagnosis are heterogeneously killed by allogenic-IL-2-NBP-expanded Vg9Vd2 T. Some are resistant to this lysis and/or poorly sensitized by NBP. BTN3 molecules are highly expressed by blasts of AML cell lines and primary AML samples. We show that treatment of primary AML blasts with agonist anti-BTN3 mAb can overcome the resistance to Vg9Vd2 cells lysis in vitro. We assess this effect in vivo, showing that the addition of agonist anti-BTN3 mAb to Vg9Vd2 cells infusion decreased the tumor burden and increased the survival of NOG mice xenografted with luciferase-transduced U937 cell line. We confirm this effect in a model of mice xenografted with primary AML blasts, showing that treatment with anti-BTN3 mAb added to Vg9Vd2 cells infusion can decrease the number of blastic cells in the spleen, bone marrow and the blood, without requiring additional cytokine infusion. This drastic effect on sensitization of primary AML blasts to Vg9Vd2T cells killing could be of great interest especially in cases of refractory or relapsing AML. Disclosures No relevant conflicts of interest to declare.

scholarly journals Targeting AXL Kinase Sensitizes Acute Myeloid Leukemia Stem and Progenitor Cells to Venetoclax Treatment

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 20-20
Author(s):  
Katharina Rothe ◽  
Xiaojia Niu ◽  
Min Chen ◽  
Rick Li ◽  
Sungeun Nam ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Treatment Strategy ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Specific Treatment ◽  
Specific Gene ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a heterogeneous haematological cancer characterized phenotypically by the rapid clonal growth of myeloid cells and an accumulation of blasts in the peripheral blood and bone marrow of patients. Despite the major progress that has been made in categorizing different genetic and molecular AML subgroups, therapies and long-term patient outcomes have not changed significantly over the past four decades. Recently, venetoclax (ABT-199), a BH3-mimetic and selective BCL-2 inhibitor, was approved for the treatment of older patients with AML. However, the limited efficacy, drug resistance in complex karyotype AML and disease progression on venetoclax as well as the inherent resistance of leukemic stem cells (LSCs) to therapy pose significant clinical challenges, warranting identification of novel targets and improved treatment strategies. One candidate target is AXL, a member of the TYRO3/AXL/MER (TAM) family of receptor tyrosine kinases. AXL and its ligand growth arrest-specific gene 6 (GAS6) are elevated in AML patients and LSCs, and associated with poor prognosis. To test whether targeting of the AXL/GAS6 pathway is a feasible treatment strategy for AML, in particular to eradicate LSCs, we developed SLC-391, a novel, potent and selective AXL inhibitor. In vitro and in vivo evaluations of the pharmaceutical properties of SLC-391 indicated reasonable solubility, excellent metabolic stability as well as desirable bioavailability in mice and rats. In silico molecular docking analysis showed that SLC391 can adopt a conformation with surface and charge complementary to the active site of the AXL kinase, potentially engaging in hydrophobic ring-mediated interactions. Further, cell-based studies discovered that SLC-391 targets AML cells with high AXL/GAS6 expression, particularly MLL+ AML cells, and synergizes with venetoclax in cell viability and apoptosis assays (CI<0.6). In addition, simultaneous AXL and BCL-2 inhibition reduced the clonal short- and long-term growth of primitive AML patient cells in CFC re-plating and LTC-IC assays compared to single or control treatments (20-95% inhibition). Moreover, a combination of AXL inhibition and venetoclax treatment was able to target LSCs and AML blasts in two different preclinical patient-derived xenotransplantation (PDX) models, extending the mean survival of these mice by 14-30 days compared to single agents (P<0.025). Mechanistically, single-cell RNA-sequencing and functional validation studies revealed that AXL inhibition perturbs oxidative metabolism, and differentially targets signaling pathways to synergize with venetoclax in leukemic cell killing. Importantly, the combination of AXL inhibition plus venetoclax treatment was not toxic to normal BM cells from healthy donors. Hence, our findings identify a promising, improved and specific treatment strategy for AML, particularly patients with high AXL/GAS6 expression. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Role of Gata2 in Murine Models of Acute Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1516-1516
Author(s):  
Taylor Yamauchi ◽  
Etienne Danis ◽  
Xi Zhang ◽  
Simone Riedel ◽  
Hua Huang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Murine Models ◽  
Self Renewal ◽  
Genetic Inactivation ◽  
Acute Myeloid

Abstract The importance of stem cell and self-renewal programs in Acute Myeloid Leukemia (AML) is generally accepted, but the molecular details are incompletely understood. The master transcriptional regulator GATA2 is highly expressed in hematopoietic stem cells (HSCs) and has critically important roles in the hematopoietic system. Gata2 is required for murine HSC development and maintenance, and heterozygous loss of Gata2 compromises murine HSC- and progenitor cell-function. High levels of GATA2-expression have been correlated with adverse prognosis in human AML. GATA2 is also overexpressed in human chronic myeloid leukemia. These data suggest an important role for GATA2 in normal stem cells and in leukemia. However, genetic lesions resulting in compromised GATA2 function can lead to MDS and in some cases AML. In a murine AML model driven by Flt3-ITD and inactivation of Tet2, Gata2 is strongly downregulated. Furthermore, mouse models of leukemia suggest that high-level forced expression of Gata2 can have a tumor suppressor role. To clarify the role of Gata2in AML we used homozygous genetic inactivation in established murine models of leukemia, using a a conditional allele. We initially tested the role of Gata2 in a murine leukemia mediated by forced expression of Meningioma1 (MN1). This model has a HoxA9/Meis1 transcriptional program. We recently found that MN1-driven leukemia depends on the histone methyltransferase Dot1l (J Clin Invest. 2016 Feb 29. pii: 80825). Lineage marker negative (Lin-), Sca1+, Kit-positive (LSK) bone marrow cells from mice with a floxed exon 5 in the Gata2 gene, and a ROSA26-YFP Cre-reporter allele were transduced with an MSCV-based ecotropic retroviral vector expressing MN1 and linked via an internal ribosomal entry site (IRES) the selectable marker GFP. Floxed Gata2-sequences were excised using transduction with a self-excising Cre-expressing vector (HR-Cre). Cells were sorted and plated in methylcellulose. The GFP/YFP double positive Gata2ko cells showed a replating defect compared to GFP single positive Gata2-floxed cells, both with regard to colony number and colony size. Next, we tested the role of Gata2 in disease maintenance in vivo. We established MN1 Gata2ff leukemias in primary recipients. Primary leukemias were transduced with Cre-expressing vector and Gata2ko and Gata2ff MN1 cells were transplanted. While all mice in the Gata2ffgroup developed leukemia with a median survival of 35 days, the mice in the Gata2ko cohort developed leukemia with incomplete penetrance with a latency of 249 days (p=0.0005). These data suggest an important role for Gata2in MN1 leukemia in vitro and in vivo. Genetic inactivation of Gata2 resulted in increased protein levels of p53 in vitro as detected by Western blot. Furthermore, MN1-transduced cells showed accentuated p53 stabilization and apoptosis in response to the Mdm2-antagonist and p53 stabilizer Nutlin3. We next tested the role of Gata2 in leukemia driven by the oncogenic fusion MLL-AF9. In contrast to the MN1 model, recipients of Gata2koleukemias only showed a trend towards prolonged latency in secondary recipients (median survival Gata2ff=48 days vs. Gata2ko=62 days, p=0.09). In this model, we also did not observe a substantial effect of Gata2-inactivation on p53 activation. We are currently characterizing the underlying molecular mechanisms. Our data document an important role for Gata2 in AML mediated by MN1 and to a lesser degree, MLL-AF9. The role of Gata2 in leukemia is complex and depends on expression levels and cellular context. A more detailed understanding of leukemic self-renewal, including the role of Gata2, will inform the development of more efficacious and less toxic therapies for this difficult-to-treat malignancy. Disclosures Bernt: Epizyme: Patents & Royalties: patent filed. Neff:Epizyme: Patents & Royalties: patent filed; Bristol Myers Squibb: Other: Travel; Janssen: Other: Travel.

CXCR4 Inhibitors Selectively Eliminate CXCR4 Expressing Human Acute Myeloid Leukemia Cells in NOG Mouse Model

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1881-1881
Author(s):  
Yanyan Zhang ◽  
Satyananda Patel ◽  
Monika Wittner ◽  
Stephane De Botton ◽  
Eric Solary ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Leukemic Cell ◽  
Cxcr4 Expression ◽  
Leukemic Cells ◽  
Acute Myeloid Leukemia Cells ◽  
Acute Myeloid

Abstract Abstract 1881 The chemokine receptor CXCR4 favors the interaction of acute myeloid leukemia (AML) cells with their niche but the extent to which it participates to pathogenesis is unclear. Here we show that CXCR4 expression at the surface of leukemic cells allowed distinguishing CXCR4high (25/47; 53%) from CXCR4neg/low (22/47, 47%) AML patients. Leukemic engraftment in NOD/Shi-scid/IL-2Rnull (NOG) mice was observed for both the CXCR4high and CXCR4neg/low groups. When high levels of CXCR4 are expressed at the surface of AML cells, blocking the receptor function with small molecule inhibitors could promote leukemic cell death and reduce NOG leukemia-initiating cells (LICs). Conversely, these drugs had no efficacy when AML cells do not express CXCR4 or when they do not respond to CXCL12. Mechanisms of this anti-leukemic effect included interference with the retention of LICs with their supportive bone marrow microenvironment niches, as indicated by a mobilization of LICs in response to drugs, and increased apoptosis of leukemic cells in vitro and in vivo. CXCR4 expression level on AML blast cells and their migratory response to CXCL12 are therefore predictive of the response to the inhibitors and could be used as biomarkers to select patients that could potentially benefit from the drugs. Disclosures: No relevant conflicts of interest to declare.

scholarly journals AZD1152 Rapidly and Negatively Affects the Growth and Survival of Human Acute Myeloid Leukemia Cells In vitro and In vivo

2009 ◽  
Vol 69 (10) ◽  
pp. 4150-4158 ◽  
Author(s):  
Adedayo Oke ◽  
Daniel Pearce ◽  
Robert W. Wilkinson ◽  
Claire Crafter ◽  
Rajesh Odedra ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Growth And Survival ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid Leukemia Cells ◽  
Acute Myeloid

scholarly journals Extracellular ATP and CD39 Regulates Mitochondrial Function and Cytarabine Resistance through Intrinsic PKA-ATF-PGC1a Pathway in Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2737-2737
Author(s):  
Jean-Emmanuel Sarry ◽  
Christian Recher ◽  
Nesrine Aroua
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Leukemic Cells ◽  
Nucleoside Triphosphate ◽  
Preclinical Model ◽  
Acute Myeloid

Abstract Relapses in acute myeloid leukemia (AML) are caused by chemoresistant leukemic populations and new therapeutic approaches that specifically target these cells are urgently needed. Based on transcriptomic analyses of relevant PDX preclinical model of the resistance to cytarabine (AraC) and of the residual disease in patients, we identified ecto-nucleoside triphosphate diphosphohydrolase-1 CD39 (ENTPD1) overexpressed in the residual leukemic cells in vivo after chemotherapy. By flow cytometry, we confirmed that AraC increased cell surface CD39 expression in AML cell lines in vitro and in vivo as well as in 24 diverse patient-derived xenograft models. We further observed this increase in 100 patients at 35-days post-intensive chemotherapy compared to their respective diagnosis. Interestingly, high CD39 expression on AML patients was associated with a worse response to AraC in vivo. Furthermore, we showed that FACS-sorted CD39high AML cells had increased mitochondrial mass and activity, and were resistant to AraC in vitro and in vivo. We demonstrated that CD39 downstream signaling pathway was dependent on cAMP-PKA-PGC1a-TFAM axis and its inhibition by H89 sensitized AML cells to AraC through the inhibition of mitochondrial OxPHOS biogenesis and function. Finally, pharmacological inhibition of CD39 ATP hydrolase activity or genetic invalidation of CD39 protein using two inhibitors or shRNA markedly enhanced AraC cytotoxicity in AML cell lines and primary patient samples in vitro and in vivo. Together, these results indicate CD39 as a new player of the intrinsic chemoresistance pathway and a new therapeutic target to specifically overcome AraC resistance and eradicate these leukemic cells responsible for relapses in AML. Disclosures No relevant conflicts of interest to declare.

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