Analysis of Prognostic Factors in Chinese Pediatric Acute Myeloid Leukemia

Abstract Objective: To describe the epidemiological profile, cytogenetic and molecular aberrations and the survival rate of patients with acute myeloid leukemia (AML) in a province reference pediatric hospital and explore their clinical features and prognosis. Patients and Methods: This is aretrospective Clinical-epidemiological study. The cohort of this study included cases of newly-diagnosed pediatric patients with non-M3- AML between 2010 and 2015, with the age younger than 14 years. The clinical characteristics such as gender, age, subtype of FAB, blood routine, bone marrow blast at the first visit, cytogenetics and molecular markers were analyzed in correlation with their prognosis between different characteristics groups. Survival analyses were calculated by Kaplan-Meier survival curves and the log rank test. Multivariate analyses on categorized data were performed using Cox proportional hazards model. Results: Of the 165 patients studied, 42.4% were females and 57.6%, males, with a age younger than 1 year in 4.8%, from 1 to 10 years in 73.4%, and older than 10 years in 21.8% ( median age 6.8 years ). According to FAB subtype, the majority subtypes were M2, M4 and M5, for 42%, 21.3% , and 26% respectively. 40.6% of patients presented a WBC count below 10 X 109/L at diagnosis while 12.7% of patients higher than 100 X 109/L. 77.0% of patients had less than 90g/L hemoglobin, and 47.9% of patients had less than 50 X 109/L platelets. In 70.0% of patients, the percentage of blasts in bone marrow was higher than 50% at diagnosis. The most common cytogenetic abnormalities in these children, including t(8;21)(q22;q22), inv(16)(p13.1q22) and 11q23/MLL-rearranged abnormalities were detected, with the occurrence of 34.1% , 12.2% and 14.0% respectively. The recurrent gene mutations rates are as the follows: 2.0% FLT3-ITD negative and NPM1 mutated, 4.9% FLT3-ITD positive and NPM1 wild type, 2.0% FLT3-ITDpositive and NPM1mutated, 3.9% FLT3-TKDpositive, 18.6% c-KIT mutation, and 2.9% PTPN11 mutation. Among the 165 cases of non-M3-AML patients, 114 cases achieved complete remission (CR) (69.1%) after one course of chemotherapy, 36 cases were relapsed, and 51 patients accepted hematopoietic stem cell transplantation (HSCT). The 3-year relapse-free survival (RFS) and overall survival (OS) rates were (62.5±3.5)% and (70.6%4±4.6)%, respectively. We failed to correlate the OS with the clinical parameters, such as gender, age, WBC, hemoglobin, blasts in BM, cytogenetic abnormalities except MLL-rearrangements, and gene mutations except FLT3-ITD and PTPN11 mutations . The patients with high platelet count, MLL -rearrangements, FLT3-ITD or PTPN11 mutation exhibited a significantly low OS rate (P£¼£¼(Table 1). Meanwhile, the RFS rate was correlated with the platelet count, FLT3-ITDand HSCT. respectively (Table 1). Multivariate analysis demonstrated that higher platelet count at diagnosis, MLL-rearrangements, FLT3-ITD and PTPN11 mutation were risk prognostic factors in childhood AML, while HSCT was a favorable factor. Conclusion:Higher platelet count at diagnosis, MLL-rearranged abnormalities, FLT3-ITD and PTPN11 mutation were poor prognostic markers in pediatric AML. HSCT could effectively improve the clinical outcome of AML patients. Table 1 Table 1. Disclosures No relevant conflicts of interest to declare.

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A leukemic stem cell with intrinsic drug efflux capacity in acute myeloid leukemia

Blood ◽

10.1182/blood.v98.4.1166 ◽

2001 ◽

Vol 98 (4) ◽

pp. 1166-1173 ◽

Cited By ~ 240

Author(s):

Gerald G. Wulf ◽

Rui-Yu Wang ◽

Ingrid Kuehnle ◽

Douglas Weidner ◽

Frank Marini ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Stem Cell ◽

Myeloid Leukemia ◽

Side Population ◽

Fluorescence Emission ◽

Drug Efflux ◽

Hematopoietic Stem ◽

Immunodeficient Mice ◽

Acute Myeloid

The hematopoietic stem cell underlying acute myeloid leukemia (AML) is controversial. Flow cytometry and the DNA-binding dye Hoechst 33342 were previously used to identify a distinct subset of murine hematopoietic stem cells, termed the side population (SP), which rapidly expels Hoechst dye and can reconstitute the bone marrow of lethally irradiated mice. Here, the prevalence and pathogenic role of SP cells in human AML were investigated. Such cells were found in the bone marrow of more than 80% of 61 patients and had a predominant CD34low/− immunophenotype. Importantly, they carried cytogenetic markers of AML in all 11 cases of active disease examined and in 2 out of 5 cases in complete hematological remission. Comparison of daunorubicin and mitoxantrone fluorescence emission profiles revealed significantly higher drug efflux from leukemic SP cells than from non-SP cells. Three of 28 SP cell transplants generated overt AML-like disease in nonobese diabetic–severe combined immunodeficient mice. Low but persistent numbers of leukemic SP cells were detected by molecular and immunological assays in half of the remaining mice. Taken together, these findings indicate that SP cells are frequently involved in human AML and may be a target for leukemic transformation. They also suggest a mechanism by which SP cells could escape the effects of cytostatic drugs and might eventually contribute to leukemia relapse.

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

Cells ◽

10.3390/cells8050482 ◽

2019 ◽

Vol 8 (5) ◽

pp. 482 ◽

Cited By ~ 5

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.

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SETDB1 mediated histone H3 lysine 9 methylation suppresses MLL-fusion target expression and leukemic transformation

Haematologica ◽

10.3324/haematol.2019.223883 ◽

2019 ◽

Vol 105 (9) ◽

pp. 2273-2285 ◽

Cited By ~ 4

Author(s):

James Ropa ◽

Nirmalya Saha ◽

Hsiangyu Hu ◽

Luke F. Peterson ◽

Moshe Talpaz ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Target Genes ◽

Critical Role ◽

High Expression ◽

Leukemia Cells ◽

Biological Impact ◽

Hematopoietic Stem ◽

Acute Myeloid

Epigenetic regulators play a critical role in normal and malignant hematopoiesis. Deregulation, including epigenetic deregulation, of the HOXA gene cluster drives transformation of about 50% of acute myeloid leukemia. We recently showed that the Histone 3 Lysine 9 methyltransferase SETDB1 negatively regulates the expression of the pro-leukemic genes Hoxa9 and its cofactor Meis1 through deposition of promoter H3K9 trimethylation in MLL-AF9 leukemia cells. Here, we investigated the biological impact of altered SETDB1 expression and changes in H3K9 methylation on acute myeloid leukemia. We demonstrate that SETDB1 expression is correlated to disease status and overall survival in acute myeloid leukemia patients. We recapitulated these findings in mice, where high expression of SETDB1 delayed MLL-AF9 mediated disease progression by promoting differentiation of leukemia cells. We also explored the biological impact of treating normal and malignant hematopoietic cells with an H3K9 methyltransferase inhibitor, UNC0638. While myeloid leukemia cells demonstrate cytotoxicity to UNC0638 treatment, normal bone marrow cells exhibit an expansion of cKit+ hematopoietic stem and progenitor cells. Consistent with these data, we show that bone marrow treated with UNC0638 is more amenable to transformation by MLL-AF9. Next generation sequencing of leukemia cells shows that high expression of SETDB1 induces repressive changes to the promoter epigenome and downregulation of genes linked with acute myeloid leukemia, including Dock1 and the MLL-AF9 target genes Hoxa9, Six1, and others. These data reveal novel targets of SETDB1 in leukemia that point to a role for SETDB1 in negatively regulating pro-leukemic target genes and suppressing acute myeloid leukemia.

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

Current Developments in Nutrition ◽

10.1093/cdn/nzaa067_062 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1835-1835

Author(s):

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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Acute myeloid leukemia–induced remodeling of the human bone marrow niche predicts clinical outcome

Blood Advances ◽

10.1182/bloodadvances.2020001808 ◽

2020 ◽

Vol 4 (20) ◽

pp. 5257-5268

Author(s):

Yiyang Chen ◽

Lina Marie Hoffmeister ◽

Yasmin Zaun ◽

Lucas Arnold ◽

Kurt Werner Schmid ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Survival Rate ◽

Clinical Outcome ◽

Myeloid Leukemia ◽

Bone Marrow Niche ◽

Dependent Manner ◽

Hematopoietic Stem ◽

Acute Myeloid ◽

First Diagnosis

Abstract Murine models of myeloid neoplasia show how leukemia infiltration alters the hematopoietic stem cell (HSC) niche to reinforce malignancy at the expense of healthy hematopoiesis. However, little is known about the bone marrow architecture in humans and its impact on clinical outcome. Here, we dissect the bone marrow niche in patients with acute myeloid leukemia (AML) at first diagnosis. We combined immunohistochemical stainings with global gene expression analyses from these AML patients and correlated them with clinical features. Mesenchymal stem and progenitor cells (MSPCs) lost quiescence and significantly expanded in the bone marrow of AML patients. Strikingly, their HSC- and niche-regulating capacities were impaired with significant inhibition of osteogenesis and bone formation in a cell contact–dependent manner through inhibition of cytoplasmic β-catenin. Assessment of bone metabolism by quantifying peripheral blood osteocalcin levels revealed 30% lower expression in AML patients at first diagnosis than in non-leukemic donors. Furthermore, patients with osteocalcin levels ≤11 ng/mL showed inferior overall survival with a 1-year survival rate of 38.7% whereas patients with higher osteocalcin levels reached a survival rate of 66.8%. These novel insights into the human AML bone marrow microenvironment help translate findings from preclinical models and detect new targets which might pave the way for niche-targeted therapies in AML patients.

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Human bone marrow depleted of CD33-positive cells mediates delayed but durable reconstitution of hematopoiesis: clinical trial of MY9 monoclonal antibody-purged autografts for the treatment of acute myeloid leukemia

Blood ◽

10.1182/blood.v79.9.2229.2229 ◽

1992 ◽

Vol 79 (9) ◽

pp. 2229-2236 ◽

Cited By ~ 69

Author(s):

MJ Robertson ◽

RJ Soiffer ◽

AS Freedman ◽

SL Rabinowe ◽

KC Anderson ◽

...

Keyword(s):

Monoclonal Antibody ◽

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Red Blood Cell Transfusion ◽

Hematopoietic Stem ◽

Myeloid Progenitor ◽

Myeloid Progenitor Cells ◽

Acute Myeloid

Abstract The CD33 antigen, identified by murine monoclonal antibody anti-MY9, is expressed by clonogenic leukemic cells from almost all patients with acute myeloid leukemia; it is also expressed by normal myeloid progenitor cells. Twelve consecutive patients with de novo acute myeloid leukemia received myeloablative therapy followed by infusion of autologous marrow previously treated in vitro with anti-MY9 and complement. Anti-MY9 and complement treatment eliminated virtually all committed myeloid progenitors (colony-forming unit granulocyte- macrophage) from the autografts. Nevertheless, in the absence of early relapse of leukemia, all patients showed durable trilineage engraftment. The median interval post bone marrow transplantation (BMT) required to achieve an absolute neutrophil count greater than 500/microL was 43 days (range, 16 to 75), to achieve a platelet count greater than 20,000/microL without transfusion was 92 days (range, 35 to 679), and to achieve red blood cell transfusion independence was 105 days (range, 37 to 670). At the time of BM harvest, 10 patients were in second remission, one patient was in first remission, and one patient was in third remission. Eight patients relapsed 3 to 18 months after BMT. Four patients transplanted in second remission remain disease-free 34+, 37+, 52+, and 57+ months after BMT. There was no treatment-related mortality. Early engraftment was significantly delayed in patients receiving CD33-purged autografts compared with concurrently treated patients receiving CD9/CD10-purged autografts for acute lymphoblastic leukemia or patients receiving CD6-purged allografts from HLA- compatible sibling donors. In contrast, both groups of autograft patients required a significantly longer time to achieve neutrophil counts greater than 500/microL and greater than 1,000/microL than did patients receiving normal allogeneic marrow. CD33(+)-committed myeloid progenitor cells thus appear to play an important role in the early phase of hematopoietic reconstitution after BMT. However, our results also show that human marrow depleted of CD33+ cells can sustain durable engraftment after myeloablative therapy, and provide further evidence that the CD33 antigen is absent from the human pluripotent hematopoietic stem cell.

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Detection of Nucleophosmin Gene Mutations in Plasma from Patients with Acute Myeloid Leukemia: Clinical Significance and Implications.

Blood ◽

10.1182/blood.v110.11.2855.2855 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2855-2855

Author(s):

Wanlong Ma ◽

Xi Zhang ◽

Iman Jilani ◽

Farhad Ravandi ◽

Elihu Estey ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Peripheral Blood ◽

Myeloid Leukemia ◽

Gene Mutations ◽

Leukemic Cells ◽

Striking Difference ◽

Plasma Dna ◽

Npm1 Mutation ◽

Acute Myeloid

Abstract Nucleotides insertion in the nucleophosphamin (NPM1) gene has been reported in about one third of patients with acute myeloid leukemia (AML). Multiple studies showed that the presence of NPM1 mutations associated with better outcome in patients with AML. Studies reported to date have analyzed leukemic cells obtained from bone marrow or peripheral blood. We tested for mutations in the NPM1 gene using peripheral blood plasma and compared results with clinical outcome from a single institution. Analyzing plasma from 98 newly diagnosed patient with AML showed NPM1 mutation in 24 (23%) of patient while only one (4%) of 28 previously untreated patients with myelodysplastic syndrome (MDS) showed NPM1 mutation. Compared with peripheral blood cells, 2 (8%) of the 24 positive patients were negative by cells; none were positive by cells and negative by plasma. Most of the mutations detected (45%) were in patients with FAB classification M2, M4 and M5. In addition to the reported 4 bp insertion, we also detected 4 bp deletion in one patient in cells and plasma. Patients with NPM1 mutation had a significantly higher white blood cell count (P = 0.0009) and a higher blast count in peripheral blood (P = 0.002) and in bone marrow (P = 0.002). Blasts in patients with NPM1 mutant expressed lower levels of HLA-DR (P = 0.005), CD13 (P = 0.02) and CD34 (P < 0.0001), but higher CD33 levels (P = 0.0004). Patients with NPM1 mutation appear to have better chance of responding to standard therapy (P = 0.06). Event free survival of patients with NPM1 mutation was longer (P = 0.056) than in patients with intermediate cytogenetic abnormalities. The most striking difference in survival was in patients who required >35 days to respond to therapy (Figure). Survival was significantly longer in patients with NPM1 mutation requiring >35 days to respond (P = 0.027). This data not only support that NPM1 plays a significant role in the biology and clinical behavior of AML, but also show that plasma DNA is enriched with leukemia-specific DNA and is a reliable source for testing. Figure Figure

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Characterization of Extramedullary Acute Myeloid Leukemia – Results of the AML96 Trial

Blood ◽

10.1182/blood.v116.21.2154.2154 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2154-2154

Author(s):

Friedrich Stölzel ◽

Christoph Röllig ◽

Michael Kramer ◽

Brigitte Mohr ◽

Uta Oelschlägel ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Induction Chemotherapy ◽

Myeloid Leukemia ◽

The Body ◽

Hematopoietic Stem ◽

Npm1 Mutation ◽

Mutation Status ◽

The Impact ◽

Acute Myeloid

Abstract Abstract 2154 Background: Myeloid Sarcoma (MS) is defined as an extramedullary mass composed of myeloid blasts occurring at an anatomical site other than the bone marrow. Furthermore, the term extramedullary manifestation (EM) is applied if it accompanies overt acute myeloid leukemia (AML) and represents non-effacing tissue infiltration. EM is reported to correspond often to the skin but can affect almost every site of the body. The prognosis of MS or EM has been discussed controversially in the past. EM at diagnosis of AML is generally thought to be a rare event. However, data defining the prevalence of EM at diagnosis of AML and its prognostic value are missing. The aim of this analysis was to provide data for estimating the prevalence of EM at diagnosis of AML and to determine its relevance by including clinical and laboratory data from patients being treated in the prospective AML96 trial of the Study Alliance Leukemia (SAL) study group. Patients and Methods: A total of 326 patients with AML (age 17 – 83 years) and EM were treated within the AML96 trial with a median follow up of 8.8 years (95% CI, 8.4 to 9.3 years). All patients received double induction chemotherapy. Consolidation therapy contained high-dose cytosine arabinoside and for patients ≤ 60 years of age the option of autologous or allogeneic hematopoietic stem cell transplantation (HSCT). Logistic regression analyses were used to identify prognostic variables for CR rates. The method of Kaplan-Meier was used to estimate OS and EFS. Confidence interval (CI) estimation for the survival curves was based on the cumulative hazard function using the Greenwood's formula for the SE estimation. Survival distributions were compared using the log rank test. Results: 17% of the AML patients entered into the AML96 trial were diagnosed with EM. In 313 of the 326 patients (96%) EM was evident at diagnosis. The majority of patients with EM were diagnosed with de novo AML (84%, n=273), whereas gingival infiltration (51%, n=166) displayed the main EM of AML with CNS involvement being less common (4%, n=14). The majority of patients had a cytogenetic intermediate risk profile (71%, n=221) with a total of 172 patients (56%) harboring a normal karyotype. Patients with EM had a statistically significant lower median CD34-positivity of bone marrow blasts, higher percentage of FAB subtypes M4 and M5, higher WBC counts and LDH at diagnosis and higher percentage of NPM1 mutations compared to those patients without EM (all p<.001). When comparing achievement of CR between patients with EM to patients without EM, no statistical difference between these two groups was observed. Analysis according to the NPM1/FLT3-ITD mutation status revealed highest 5-year-OS (37%, 95% CI: .24 - .508) and 5-year-EFS (36%, 95% CI: .224 - .448) in the NPM1-mut/FLT3-wt group and lowest 5-year-OS (12%, 95% CI: 0 - .261) and 5-year-EFS (4%, 95% CI: 0 - .124) in the NPM1-wt/FLT3-ITD group, p=.007 and p=.001, respectively. Of the 49 relapsed patients with EM who had a NPM1-mutation at diagnosis 48 deceased despite of intensified relapse therapies. Conclusions: This analysis represents the largest study so far investigating the impact of EM AML. Patients with EM AML have distinct differences from AML patients without EM regarding their clinical and molecular characteristics at diagnosis. However these differences do not translate into differences in response to induction chemotherapy. Compared to patients without EM, survival analysis revealed differences according to the NPM1/FLT3-ITD mutation status which is also described for patients without EM AML. However, the prognosis for patients with EM who harbor a mutated NPM1 the prognosis at relapse seems to be dismal. Disclosures: No relevant conflicts of interest to declare.

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

Blood ◽

10.1182/blood.v118.21.559.559 ◽

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.

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Hematopoietic Stem Cell Transplantation (HSCT) Benefits the Survival of Acute Myeloid Leukemia (AML) Patients with IDH1, NRAS and DNMT3A Mutations

Blood ◽

10.1182/blood.v120.21.1981.1981 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1981-1981

Author(s):

Yang Xu ◽

Zhen Yang ◽

Hong Tian ◽

Huiying Qiu ◽

Aining Sun ◽

...

Keyword(s):

Overall Survival ◽

Acute Myeloid Leukemia ◽

Stem Cell ◽

Hematopoietic Stem Cell Transplantation ◽

Stem Cell Transplantation ◽

Myeloid Leukemia ◽

Gene Mutations ◽

Newly Diagnosed ◽

Hematopoietic Stem ◽

Acute Myeloid

Abstract Abstract 1981 Background: Gene mutations may serve as potential markers to extend the prognostic parameters in acute myeloid leukemia (AML) patients. In this study, we detected distribution of mutations in the nucleophosmin gene (NPM1), C-KIT, the fms-related tyrosine kinase 3 gene (FLT3), Isocitrate dehydrogenase gene 1 and 2 (IDH1, IDH2), the neuroblastoma RAS viral oncogene homolog (NRAS) and DNA methyltransferase 3A gene (DNMT3A) in 442 newly diagnosed AML patients (none-APL). Associations of gene mutations with clinical outcomes in these patients followed HSCT treatment or chemotherapy were further evaluated. Methods: Between February 2005 and December 2011, 442 newly diagnosed AML (none-APL) patients in our centre were retrospectively analyzed. There are 248 males and 194 females, and the median ages were 40 (16–60) years. 393 patients (88.9%) of patients were with single or normal karyotype and 49 patients (11.1%) were with complex abnormal karyotype. In addition to MICM examination, direct sequencing was employed to access the distribution of mutations in of FLT3-ITD (exon14), FLT3-TKD (exon 20), NPM1 (exon12), C-KIT (exon8, 17), IDH2 (exon 4), NRAS (exon1, 2), DNMT3A (exon23) of 445 AML patients. Complete remission (CR) was achieved in 258 patients (58.4%) followed the standard induction therapy, 128 patients received HSCT (Allo-HSCT: 121 vs. Auto-HSCT: 7) therapy after first remission or second remission while 258 patients received consolidation chemotherapy contained 4–6 cycles high dose Ara-C (HD-Ara-C). Overall survival (OS) and Event-free survival (EFS) were measured at last follow-up (censored), and Kaplan-Meier analysis was used to calculate the distribution of OS and EFS. Results: In 442 AML (None-APL) patients, 44 patients (9.7%) had C-KIT mutations, 97 patients (21.9%) had NPM1 mutations, 95 patients (21.5%) had FLT3-ITD mutations, 26 patients (5.9%) had FLT3-TKD mutations, 23 patients (5.2%) had IDH1 mutations, 48 patients (10.9%) had IDH2 mutations, 31 patients (7.0%) had DNMT3A mutations, and 40 patients (9.0%) had NRAS mutations. Using COX regression, we found that mutations in FLT3-ITD (HR:2.113; 95%CI: 1.1420 to 3.144),IDH1 (HR:3.023; 95%CI: 1.055 to 3.879), NRAS (HR:1.881; 95%CI: 1.021 to 2.945), and DNMT3A (HR: 2.394; 95%CI: 1.328 to 4.315) were independent unfavorable prognostic indicators of overall survival of AML patients. We further compared the outcomes of AML patients with such gene mutations followed different therapy (HSCT vs. HD Ara-C), and results shown that patients with mutations in IDH1, NRAS and DNMT3A received HSCT therapy had better survival. The median OS and EFS of patients with FLT3-ITD, IDH1, NRAS and DNMT3A in the two groups (HSCT vs. HD Ara-C) were as follows: IDH1 (OS: 35 months vs. 11 months, p=0.016; EFS: 34 months vs. 8 months, p=0.012), NRAS (OS: 27months vs. 8 months, p=0.008; EFS: 23 months vs. 4 months, p=0.049), DNMT3A (OS: 66 months vs. 19 months, p=0.008; EFS: 54 months vs. 13 months, p=0.002). Conclusions: Taken together, our data proved that mutant FLT3-ITD, IDH1, NRAS, and DNMT3A might serve as poor prognostic markers and hematopoietic stem cell transplantation as first-line treatment could favor the outcome of AML patients carrying IDH1, NRAS, and DNMT3A mutations. Disclosures: No relevant conflicts of interest to declare.

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