Metabolic Reprogramming of Human Mitochondrial NAD(P)+-Dependent-Malic Enzyme 2 in Acute Myeloid Leukemia

Yu-Nan Huang1, Kang-Hsi Wu4, Te-fu Weng4, Su-Ching Liu4, Hui-Chih Hung1*, Ching-Tien Peng4,5* FLT3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukemia (AML) are usually associated with other mutations resulting in unfavorable outcome. Tyrosine kinase inhibitors (TKI) have shown promising responses, however, these responses are almost transient in therapy-resistant AML. Here, we show that human mitochondrial NAD(P)+-dependent-malic enzyme 2 (ME2) have significantly increased in CD34+ cell of patients with AML. To determine how ME2 establish metabolic reprogramming of leukemogenesis, we performed a comprehensive analysis of metabolism in CRISPR-mediated ME2 knockout leukemic cells (THP-1 and MV4-11) and purified leukemic blast cells (CD34+) derived from patients with AML. We demonstrate that disrupting ME2 signaling exerts potent activities against proliferation, reduced oxidative metabolism and lactate metabolism. We also show that genetic inhibition of RUNX1/FLT3/ME2 markedly repressed AML cell leukemogenesis. In conclusion, our findings provide a rationale for clinical development of this strategy for treating RUNX1 and FLT3-mutated leukemic patients. Disclosures No relevant conflicts of interest to declare.

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Quizartinib in the treatment of FLT3-internal-tandem duplication-positive acute myeloid leukemia

Future Oncology ◽

10.2217/fon-2019-0353 ◽

2019 ◽

Vol 15 (34) ◽

pp. 3885-3894 ◽

Cited By ~ 1

Author(s):

Shilpa Paul ◽

Adam J DiPippo ◽

Farhad Ravandi ◽

Tapan M Kadia

Keyword(s):

Acute Myeloid Leukemia ◽

Tyrosine Kinase ◽

Myeloid Leukemia ◽

Tandem Duplication ◽

Kinase Inhibitors ◽

Single Agent ◽

Tyrosine Kinase Domain ◽

Missense Mutations ◽

Internal Tandem Duplication ◽

Acute Myeloid

FLT3 mutations, characterized by an internal-tandem duplication or missense mutations in the tyrosine kinase domain, are observed in a third of patients with newly diagnosed acute myeloid leukemia. FLT3-ITD mutations are associated with high relapse rates and short overall survival with conventional chemotherapy. Several tyrosine kinase inhibitors targeting FLT3 have been developed in an effort to improve survival and therapeutic options. This review focuses on quizartinib, a second-generation FLT3 inhibitor that has demonstrated efficacy and safety as a single agent and in combination with chemotherapy. We discuss its clinical development as well as its place in the treatment of FLT3-mutated acute myeloid leukemia among the other FLT3 inhibtors currently available and its mechanisms of resistance.

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Fucose binding lectin for characterizing acute myeloid leukemia progenitor cells

Blood ◽

10.1182/blood.v68.1.41.41 ◽

1986 ◽

Vol 68 (1) ◽

pp. 41-45 ◽

Cited By ~ 14

Author(s):

R Delwel ◽

I Touw ◽

F Bot ◽

B Lowenberg

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Fluorescence Analysis ◽

Leukemic Cells ◽

Ulex Europaeus ◽

Acute Myeloid Leukemia Cells ◽

Blast Cells ◽

Binding Lectin ◽

Acute Myeloid

Abstract The reactivity of acute myeloid leukemia cells (AML) was determined in 29 patients using the fucose binding lectin Ulex europaeus agglutinin (UEA) as surface marker. We show a marked heterogeneity in the UEA- binding abilities of the cells in these patients as determined by fluorescence analysis of the blasts labeled with the UEA coupled to the fluorescent molecule FITC. The results suggest a correlation between the capability of AML blast cells to bind UEA and cytologic maturation, because in 1 of 10 M1, 3 of 8 M2, 6 of 8 M4, and 1 of 3 M5 cytology types UEA binding to the leukemic cells was apparent. In 13 cases, the cells gave rise to colonies in vitro. The amount of UEA binding to AML colony-forming cells (AML-CFU) was determined by cell sorting and subsequent colony culture of UEA-negative, intermediately positive, and highly fluorescent cells. AML-CFU from none of the four patients with M1 cytology were UEA positive, whereas they showed intense reactivity with the lectin in 1 of 4 cases with M2 cytology and in all 4 cases of M4. In these five cases with strongly UEA positive AML-CFU, the fluorescence distribution of the colony formers differed from that of the total leukemia population, indicating that AML-CFU represent a subpopulation of AML cells with specific UEA-binding properties. Normal bone marrow myeloid and multipotential colony-forming cells (CFU-GM, CFU-GEMM) showed low or no binding of UEA. UEA-FITC appears a useful reagent for membrane analysis of AML-CFU. In certain cases, UEA-FITC labeling may be applied to discriminate AML-CFU from normal hematopoietic progenitors.

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Acute Myeloid Leukemia with Mutated NPM1 Presenting with Life-Threatening, Either Arterial or Venous, Thromboembolism: a Report of 4 Cases.

Blood ◽

10.1182/blood.v114.22.4135.4135 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4135-4135

Author(s):

Maria Paola Martelli ◽

Lorenzo Brunetti ◽

Luca De Carolis ◽

Elisabetta Agliani ◽

Laura Berchicci ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Venous Thromboembolism ◽

Myeloid Leukemia ◽

Thromboembolic Event ◽

Conflicts Of Interest ◽

The Other ◽

Leukemic Cells ◽

Acute Ischemia ◽

Life Threatening ◽

Acute Myeloid

Abstract Abstract 4135 Acute myeloid leukemia (AML) expressing mutated NPM1 gene and cytoplasmic nucleophosmin (NPMc+ AML) [Falini B et al, NEJM 2005;352:254-266] is a new entity of WHO classification that shows distinctive biological and clinical features. AML with mutated NPM1 usually presents with a high white blood cell count; the bone marrow biopsy is usually markedly hypercellular and leukemic cells frequently show myelomonocytic or monocytic features, with dysplasia and involvement of two or more cell lineages in about 25% of cases. Lack, or low expression, of CD34 in over 90% of cases is the most distinctive immunophenotypic feature of NPM1-mutated AML and is independent of leukemic cell maturation. NPM1 gene mutation without concomitant FLT3-ITD identify a subgroup of AML patients with a favorable prognosis and has been associated with an approximately 50-60% probability of survival at 5 years in younger patients. Here we report 4 out of 41 (10%) patients, admitted at our Hospital in the last year, with new-diagnosed AML with mutated NPM1 presenting with life-threatening thromboembolic (either arterial or venous) events. The main characteristics of these patients are summarized in Table 1. The patients had neither personal nor family history concerning thromboembolism. Hyperleukocytosis was a common feature of the vast majority of NPM1-mutated AML patients at diagnosis. Immunophenotypic analysis did not show a peculiar phenotype in these patients. Table 1 Characteristics of patients with NPM1-mutated AML and thrombosis. Case report no Age Sex (M/F) FAB subtype WBC/mmc Type of thrombosis Site of thrombosis 1 41 F M1 14970 arterial Anterior interventricular branch of left coronary artery 2 56 M M4 93990 arterial external iliac and femoral (right limb) 3 63 M M2 113000 deep venous great saphenous veins (bilateral) 4 73 F M4 190000 deep venous iliac and femoral In two patients (cases 1 and 2), the arterial thromboembolic event (acute myocardial infarction and acute ischemia of right lower limb, respectively) presented about one month before diagnosis of leukemia. In the other 2 patients (cases 3 and 4), deep venous thromboembolism was concomitant with the diagnosis of leukemia. One patient (case 4), who could not initiate chemotherapy for severe concomitant renal failure, died few days after diagnosis. The other patients recovered from the acute event and upon diagnosis of leukemia were promptly treated with standard polychemotherapy which allowed to obtain complete hematological remission associated with complete resolution of the thromboembolic event. The clinical course after chemotherapeutic treatment of the patients outlines the importance and life saving role of early chemotherapy even under adverse circumstances. The pathogenesis of thromboembolic disease in hematological malignancies is complex and multifactorial: tumor cell-derived procoagulant, fibrinolytic or proteolytic factors and inflammatory cytokines affect clotting activation. Other important factors include infectious complications and hyperleukocytosis. However, large vessel thrombosis is a very rare clinical presentation. Our report of severe thromboembolic events at presentation in AML with mutated NPM1 suggests some still unidentified biological features of this leukemia which we are currently investigating. Disclosures: No relevant conflicts of interest to declare.

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Immunophenotyping Features in Acute Myeloid Leukemia (AML) with NPM1+ and/or FLT3+

Blood ◽

10.1182/blood.v118.21.4908.4908 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4908-4908

Author(s):

Pervin Topcuoglu ◽

Klara Dalva ◽

Sinem Civriz Bozdag ◽

Onder Arslan ◽

Muhit Ozcan ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Leukemic Cells ◽

Aberrant Expression ◽

Hla Dr ◽

Cd36 Expression ◽

Cd34 Cells ◽

Cd56 Expression ◽

Acute Myeloid

Abstract Abstract 4908 Immunophenotyping Features in Acute Myeloid Leukemia (AML) with NPM1 and/or FLT-3 Positive Pervin Topçuoglu, Klara Dalva, Sinem Civriz Bozdag, Önder Arslan, Muhit Özcan, Osman Ýlhan, Hamdi Akan, Meral Beksaç, Günhan Gürman Aim: We aimed to evaluate immunophenotypical (IP) features in AML pts with NPM1+ and/or FLT3+ except on acute promyelocytic leukemia. Patients&Method: Between Nov 2009 and Feb 2011, we retrospectively analyzed IP features by flow cytometry (FCM) in 51 pts (46M;17F) with new diagnosed AML. Median age was 46 years (range: 14–71 ys). The mutations of NMP1 and FLT-3 TKD&ITD were determined by the methods of RQ-PCR or RFLP, respectively in the samples of bone marrow (n=31) or periheral blood (n=20) at the diagnosis. Antigenic expression of leukemic cells was analyzed by four-color FCM (FITC, PE, PerCP&APC) based by Nomdedeu et al researh (Leuk res 2011; 35:163) (Table-1). Results: We detected NMP1+ mutation in 16 patients. Of these, three were associated with mutations of FLT3-ITD (n=2) or -TKD (n=1). Twelve patients had FLT3+ (9 ITD or 3 TKD). More than half of the patients without any mutation were CD15+/CD34+/HLA-DR+ and 11.5% for CD34 negative. Similarly, the patients with FLT-3 positive were mostly CD34+ as the pts w/o any mutations. Contrary, most of the pts with NMP1+ were CD34 negative (56.3%) (Table 1). When evaluated the complete IP in leukemic cells, the expression of CD123 was significantly marked in the patients with NPM1+ and/or FLT3+ than those w/o mutations (p=0.008). While the co-expression of CD7 and CD117 was found in 67% of the pts w/o any mutations, 30% of the pts with NMP1 and/or FLT-3 ITD (p=0.01). CD56 expression was detected in more pts with NMP1+ than those with FLT-3+ (40% vs 8%, p=0.04). Besides, CD36 expression was positive in the all pts with FLT3-ITD than TKD+ (p=0.005). More intensive CD33 expression was seen in NMP1+ pts. The expression of CD64 was similar in all three mutations. Conclusion: Though NMP1 mutation was associated more CD34+ cells, more FLT3+ pts had CD34 positivity. The expression of CD123 was especially associated with the mutations. Aberrant expression of CD56 was in more pts with NPM1+, but CD36 for FLT3-ITD. These data might be a step for a study aiming to show a correlation between the type of mutations combined with IP features of leukemic cells and clinical characteristics or disease course of AML pts. Disclosures: No relevant conflicts of interest to declare.

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Unraveling The Leukemic Nature Of hMICL and CD123 Expressing Cells In Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v122.21.2626.2626 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2626-2626 ◽

Cited By ~ 2

Author(s):

Line Nederby ◽

Peter Hokland ◽

Gordon Brown ◽

Maria Hansen ◽

Charlotte Guldborg Nyvold ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Capillary Electrophoresis ◽

Myeloid Leukemia ◽

Mononuclear Cells ◽

Conflicts Of Interest ◽

Leukemic Cells ◽

Fragment Analysis ◽

Marker Combination ◽

Allelic Burden ◽

Acute Myeloid

Abstract Flow cytometry constitutes a cornerstone in the diagnosis and follow up of acute myeloid leukemia (AML) and it is based on the identification of leukemia-associated immunophenotypes (LAIPs). We have recently demonstrated that the C-type lectin hMICL in combination with CD123 constitute a highly stable and reliable LAIP marker combination at diagnosis and relapse. In addition, we have shown that an hMICL/CD123-based assay is an effective tool for the monitoration of minimal residual disease (MRD) in AML. To what extent hMICL/CD123 marking identifies early leukemic cells is, however, not established. We hypothesized that this could be addressed by studying molecular aberrations in leukemic cell subsets according to their expression of hMICL and CD123. Employing cell sorting and mutational analyses, we here establish the leukemic origin of hMICL and CD123 expressing cell populations. Analyzing diagnostic AML samples with homozygous FLT3-ITD aberrations allowed for verification of pure malignant clones. Five patients with FLT3-ITD allelic burden of >50% (range 77-93%, median 85%) as measured by DNA fragment analysis by capillary electrophoresis on mononuclear cells (MNC) were identified in our local database of 600 cases. We found that 5/5 patients displayed a normal karyotype and carried NPM1 mutations (NPM1 allelic burden 42-48%, median 46%). In contrast, mutations in FLT3-D835, IDH1-R132, c-KIT-D816V or indel mutations in CEBPA and WT-1 exon 7 were absent. From samples of cryopreserved mononuclear cells (bone marrow (n=4) and peripheral blood (n=1)), CD45low/SSClow blast cell subsets with the following immunophenotypes were sorted by FACS: CD34+/hMICL+/CD123+, CD34+/hMICL+/CD123-, CD34+/hMICL-/CD123+, and CD34+/hMICL-/CD123-. In one case of CD34 negative AML the sorted subsets were CD34-/hMICL+/CD123+, CD34-/hMICL+/CD123-, CD34-/hMICL-/CD123+, and CD34-/hMICL-/CD123-. Sorted cell subsets were analyzed for FLT3-ITD and NPM1 mutations using fragment analysis by capillary electrophoresis. The results of the fragment analyses are tabulated in the table below. In all cases the hMICL and CD123 expressing subsets of interest closely approximated 100% FLT3-ITD allelic burden. In contrast, hMICL-/CD123- cells approximated only a 50% FLT3-ITD allelic burden. Of note, an extended search in our AML database, revealed only 9 of 600 patients to have an FLT3-ITD allelic burden >50% (range 52-94%, median 81%) hence indicating a state of either homo- or hemizygosity. Interestingly, with the exception of one case carrying a chromosome 13 duplication, each of these 9 patients also harbored a mutation in the NPM1 gene as the only other known aberration. In conclusion using AML patients with high FLT3-ITD allelic burdens we have been able to show that blasts expressing hMICL and/or CD123 at diagnosis are indeed malignant thus further substantiating the use of these antigens in AML MRD detection. Additionally, a direct relationship between NPM1 and FLT3-ITD homo-/hemizygosity may be suggested in the evolution of the malignant clone.Phenotype of sorted cell subsetNumber of patientsFLT3-ITD allelic burden (%) Min-max (median)NPM1 allelic burden (%) Min-max (median)MNC577-93 (85)42-48 (46)CD45low/SSClow/CD34+/hMICL+/CD123+495-100 (98)48-50 (49)CD45low/SSClow/CD34+/hMICL+/CD123-1*9248CD45low/SSClow/CD34+/hMICL-/CD123+497-100 (99)47-51 (48.5)CD45low/SSClow/CD34+/hMICL-/CD123-436-68 (47)16-38 (25)CD45low/SSClow/CD34-/hMICL+/CD123+110046CD45low/SSClow/CD34-/hMICL+/CD123-19448CD45low/SSClow/CD34-/hMICL-/CD123+110047CD45low/SSClow/CD34-/hMICL-/CD123-17735*Subset only present in one of four patients Disclosures: No relevant conflicts of interest to declare.

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TIM-3 Is Highly Expressed On Blast Cells In Patients With Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v122.21.4931.4931 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4931-4931

Author(s):

Caixia Li ◽

Xiao Yu ◽

Yibei Zhu ◽

Xiaojin Wu ◽

Xiao Ma ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Peripheral Blood ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Univariate Analysis ◽

Negative Regulator ◽

Clinical Implications ◽

Potential Marker ◽

Blast Cells ◽

Acute Myeloid

Abstract T cell immunoglobulin-3(TIM-3) is known as a negative regulator in anti-tumor immunity through its reaction with TIM-3 ligand, galectin-9. It has been confirmed that TIM-3 is expressed on Th1 cells, dendritic cells, monocytes, macrophages, malignant stem cells and so on. But the expression of TIM-3 and its clinical implications in patients with acute myeloid leukemia(AML) remains unknown. In this study, we sought to determine the expression and clinical implications of TIM-3 in AML. From August 2012 to June 2013, in total of 32 AML patients with sixteen male and sixteen female were enrolled in this study. We collected their peripheral blood before they received any treatment and then obtained their peripheral blood mononuclear cells(PBMC). Monoclonal antibody was added into PBMC and cell population was analyzed by flow cytometry. Blast cells were identified with SSC CD45±and mature lymphocytes with SSC CD45+. The average expression of TIM-3 on blast cells was 43.46%, while on mature lymphocytes was 13.78% (P<0.001). In univariate analysis, the level of expression was not correlated to the percentage of blast cells and there was no difference between each type of AML. Complete remission was similar between different levels of TIM-3 expression(P>0.05). These results demonstrated that TIM-3 was highly expressed on blast cells than on mature cells in AML, which indicated that TIM-3 could be associated with the differentiation of blast cells and a potential marker to detect the tendency of relapse. TIM-3-targeted antitumor therapy presents a perspective possibility. Disclosures: No relevant conflicts of interest to declare.

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ETO2-GLIS2 Controls Differentiation Arrest and Self-Renewal through Aberrant Enhancers Regulation in Pediatric Leukemia

Blood ◽

10.1182/blood.v128.22.572.572 ◽

2016 ◽

Vol 128 (22) ◽

pp. 572-572

Author(s):

Cecile Thirant ◽

Cecile K Lopez ◽

Cathy Ignacimouttou ◽

M'Boyba Diop ◽

Lou Le Mouël ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Genetic Alterations ◽

Leukemic Cells ◽

Hematopoietic Progenitors ◽

Pediatric Leukemia ◽

Self Renewal ◽

Megakaryocytic Differentiation ◽

Acute Myeloid

Abstract Deregulated gene expression due to genetic alterations, such as gene fusions affecting transcription and/or epigenetic factors is the hallmark of acute myeloid leukemia and the basis for the differentiation block of hematopoietic progenitors. Acute megakaryoblastic leukemia (AMKL) is a subtype of poor prognosis acute myeloid leukemia (AML) affecting primarily young children. Recently, the ETO2-GLIS2 fusion has been identified in 20-30% of de novo AMKL and associated with the worst prognosis in this subtype of AML. To characterize the transformation induced by ETO2-GLIS2, we first defined the consequences of ETO2-GLIS2 expression on hematopoietic progenitors and the contribution of ETO2 and GLIS2 on differentiation and self-renewal. Using methylcellulose replating assays and phenotype characterization, we show that the GLIS2 moiety drives the megakaryocytic phenotype whereas both the ETO2 and GLIS2 moieties are required for maintaining self-renewal. Global expression profiling and comparison to patients' signature consistently identify ETO2-GLIS2-mediated deregulation of major transcriptional regulators of hematopoiesis and leukemogenesis, including overexpression of the ERG oncogene. ChIP-seq analysis reveals that ETO2-GLIS2 is recruited at normal ETO2 complexes sites and also at GLIS2-specific targets through binding via GLIS2 DNA-binding domain. We demonstrate that ETO2-GLIS2 fusion localize at half of H3K27Ac-dense enhancers, so called super-enhancers, to control transcription of associated genes. We show that interaction of ETO2-GLIS2 with ETO2 complexes is an essential node for the transcriptional control by the fusion at enhancer elements. Indeed, ETO2-GLIS2 dimerizes and interacts with endogenous ETO2 via its NHR2 domains. An NHR2 peptide-interference strategy inhibits oligomerization, reverses the transcriptional activation at enhancers, promotes megakaryocytic differentiation and abrogates human AMKL cells maintenance in vivo. Finally, upregulation of ERG by ETO2-GLIS2 further strengthen enhancers formation as ERG is co-recruited generating a feed forward loop at these elements and its knockdown or genetic inactivation downregulates expression of ETO2-GLIS2 targets required for leukemic cells survival. We propose that the megakaryocytic differentiation arrest and self-renewal controlled by ETO2-GLIS2 results from an imbalance in the expression of master transcription factors imposed by aberrant chromatin structures at enhancers that may be disrupted by targeting the NHR2 interface. Disclosures No relevant conflicts of interest to declare.

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Clinical Implications of Inflammation in Acute Myeloid Leukemia

Frontiers in Oncology ◽

10.3389/fonc.2021.623952 ◽

2021 ◽

Vol 11 ◽

Cited By ~ 1

Author(s):

Christian Récher

Keyword(s):

Acute Myeloid Leukemia ◽

Disease Progression ◽

Myeloid Leukemia ◽

Kinase Inhibitors ◽

Lymphoblastic Leukemia ◽

Clonal Evolution ◽

Leukemic Cells ◽

Prognostic Impact ◽

Acute Myeloid

Recent advances in the description of the tumor microenvironment of acute myeloid leukemia, including the comprehensive analysis of the leukemic stem cell niche and clonal evolution, indicate that inflammation may play a major role in many aspects of acute myeloid leukemia (AML) such as disease progression, chemoresistance, and myelosuppression. Studies on the mechanisms of resistance to chemotherapy or tyrosine kinase inhibitors along with high-throughput drug screening have underpinned the potential role of glucocorticoids in this disease classically described as steroid-resistant in contrast to acute lymphoblastic leukemia. Moreover, some mutated oncogenes such as RUNX1, NPM1, or SRSF2 transcriptionally modulate cell state in a manner that primes leukemic cells for glucocorticoid sensitivity. In clinical practice, inflammatory markers such as serum ferritin or IL-6 have a strong prognostic impact and may directly affect disease progression, whereas interesting preliminary data suggested that dexamethasone may improve the outcome for AML patients with a high white blood cell count, which paves the way to develop prospective clinical trials that evaluate the role of glucocorticoids in AML.

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Fucose binding lectin for characterizing acute myeloid leukemia progenitor cells

Blood ◽

10.1182/blood.v68.1.41.bloodjournal68141 ◽

1986 ◽

Vol 68 (1) ◽

pp. 41-45 ◽

Cited By ~ 1

Author(s):

R Delwel ◽

I Touw ◽

F Bot ◽

B Lowenberg

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Fluorescence Analysis ◽

Leukemic Cells ◽

Ulex Europaeus ◽

Acute Myeloid Leukemia Cells ◽

Blast Cells ◽

Binding Lectin ◽

Acute Myeloid

The reactivity of acute myeloid leukemia cells (AML) was determined in 29 patients using the fucose binding lectin Ulex europaeus agglutinin (UEA) as surface marker. We show a marked heterogeneity in the UEA- binding abilities of the cells in these patients as determined by fluorescence analysis of the blasts labeled with the UEA coupled to the fluorescent molecule FITC. The results suggest a correlation between the capability of AML blast cells to bind UEA and cytologic maturation, because in 1 of 10 M1, 3 of 8 M2, 6 of 8 M4, and 1 of 3 M5 cytology types UEA binding to the leukemic cells was apparent. In 13 cases, the cells gave rise to colonies in vitro. The amount of UEA binding to AML colony-forming cells (AML-CFU) was determined by cell sorting and subsequent colony culture of UEA-negative, intermediately positive, and highly fluorescent cells. AML-CFU from none of the four patients with M1 cytology were UEA positive, whereas they showed intense reactivity with the lectin in 1 of 4 cases with M2 cytology and in all 4 cases of M4. In these five cases with strongly UEA positive AML-CFU, the fluorescence distribution of the colony formers differed from that of the total leukemia population, indicating that AML-CFU represent a subpopulation of AML cells with specific UEA-binding properties. Normal bone marrow myeloid and multipotential colony-forming cells (CFU-GM, CFU-GEMM) showed low or no binding of UEA. UEA-FITC appears a useful reagent for membrane analysis of AML-CFU. In certain cases, UEA-FITC labeling may be applied to discriminate AML-CFU from normal hematopoietic progenitors.

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Complete hematologic remissions induced by 2-chlorodeoxyadenosine in children with newly diagnosed acute myeloid leukemia

Blood ◽

10.1182/blood.v84.4.1237.1237 ◽

1994 ◽

Vol 84 (4) ◽

pp. 1237-1242 ◽

Cited By ~ 47

Author(s):

VM Santana ◽

CA Hurwitz ◽

RL Blakley ◽

WR Crom ◽

X Luo ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Plasma Concentrations ◽

Leukemic Cells ◽

Remission Induction ◽

Significant Activity ◽

Newly Diagnosed ◽

Blast Cells ◽

Acute Myeloid

Abstract The majority of children with acute myeloid leukemia (AML) who are treated exclusively with chemotherapy die of progressive disease. Improvement in outcome will likely require new active drugs capable of eradicating resistant blast cells early in the clinical course. We therefore assessed the cytoreductive potential of 2- chlorodeoxyadenosine (2-CdA), a halogenated purine analogue, in 22 consecutive children with newly diagnosed AML. The drug was administered as a single 120-hour continuous infusion (8.9 mg/m2 of body surface area per day) before the introduction of standard remission induction therapy. Six patients (27%) had complete hematologic remissions by a median of 21 days after treatment with the nucleoside (range, 14 to 33 days). Seven others had partial responses, yielding a total response rate of 59%. The drug also eliminated leukemic cells from cerebrospinal fluid in 4 of the 6 patients tested. Concentrations of 2-CdA in cerebrospinal fluid on day 5 after the initiation of treatment ranged from 12.4% to 38.0% (mean, 22.7%) of the steady-state plasma concentrations. Severe but reversible myelosuppression and thrombocytopenia developed in all patients. Analysis of factors that may have influenced the complete remission rate suggested a better outcome in patients with myeloblastic leukemia (M0-M2 subtypes in the revised French-American-British classification system). These results demonstrate clinically significant activity by 2- CdA against previously untreated AML in children, including leukemic blast cells in the central nervous system. Its use in combination chemotherapy may improve the outlook for patients with this often fatal hematologic cancer.

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