Histone abnormalities in adult acute leukemias

Arginine-rich and lysine-rich histones were extracted from various cytologic types of leukemic blasts and from preparations rich in normal monocytes. On polyacrylamide disc electrophoresis, the patterns of normal monocyte histones closely resembled those found in acute histiomonocytic leukemia (Schilling type). The electrophoretic patterns of histones obtained from leukemic blasts in acute myelomonocytic leukemia (Naegeli type) were similar to those found in both acute myelobastic leukemia and chronic granulocytic leukemia. The results support the concept that acute myelomonocytic leukemia may be closely related to, or a variant of, acute myeloblastic leukemia, and that acute histiomonocytic leukemia is most probably a monocytic rather than a myeloblastic disorder. In addition to accepted morphologic and enzymatic criteria, the present studies suggest that differences in histone patterns might be useful in further distinguishing between histiomonocytic, myeloblastic, and myelomonocytic leukemias.     

Juvenile and adult types of chronic granulocytic leukemia of childhood: Growth patterns and characteristics of granulocyte-macrophage colony forming cells

Peripheral blood and bone marrow cells from three children with the juvenile (Ph¹ negative) type of chronic granulocytic leukemia and from one with the adult (Ph¹ positive) type were cultured in soft agar, and their specific growth patterns were evaluated. Greatly increased numbers of colonies were obtained in all cases, particularly from peripheral blood cells. By morphologic, cytochemical and ultrastructural criteria, colonies from one juvenile type and from the single adult type patients were found to be almost exclusively granulocytic, whereas in the other two juvenile type leukemia patients colonies were either granulocytic or macrophage. Moreover, both growth patterns were obtained in the same patients on different occasions. It appears that the leukemic cell populations of the juvenile and the adult forms of chronic granulocytic leukemia do not arise from different cell lines. Rather, both are the progeny of the common monocyte-granulocyte progenitor cell, whose abnormal proliferation and differentiation along either the granulocytic or the monocytic pathway is probably directed by fluctuations in humoral and/or microenvironmental factors.     

Clinical utility of marrow cell tissue cultures in acute leukemia of childhood

To determine the clinical value of tissue culture techniques in the study of acute leukemia, marrows from 50 children (40 acute lymphoblastic [ALL], 10 acute myeloblastic [AML]) were cultured by the use of an AML blast colony assay and the CFU-GEMM assay. In the AML assay, AML marrow gave rise to high numbers of blast colonies within 24 to 48 hr; in sharp contrast, 37 of 40 ALL marrows did not yield colonies in this assay. In the CFU-GEMM assay, AML marrow produced excessive numbers of monocyte-macrophage CFU-C colonies, an obvious background of individual macrophages and clusters, and occasional blast colonies. ALL marrow yielded very low numbers of granulocytic CFU-C colonies, no background of macrophage cells, and no blast colonies. These clear-cut differences in cellular growth kinetics in vitro between ALL and AML marrows should allow confirmation of the type of acute leukemia within 24 to 48 hr. The colony assays may also be valuable in differentiating ALL from AML in difficult diagnoses when conventional approaches are nondiagnostic.     

"Monocytic" Cells of Normal Blood, Schilling and Naegeli Leukemia, and Leukemic Reticuloendotheliosis in Slide Chambers

1. The study of living blood cells in slide chambers by phase microscopyand cinemicrography adds useful morphologic, developmental and physiologicdata complementary to other methods for studying blood cells.

2. Normal monocytes were characterized by flattening in fresh serum withminimal ameboid motility, by ectoplasmic veils waving in the medium, andby transformation to fully developed macrophages in 5-7 days.

3. Cells from four patients with acute monocytic leukemia (Schilling type)showed only slight differences in morphology, development and function fromnormal monocytes in the slide chamber.

4. Monocytoid cells from four patients with myelomonocytic leukemia(Naegeli type), in the slide chamber, resembled those from two patients withleukemic reticuloendotheliosis in morphology, development and function, butdiffered from normal monocytes and cells of acute monocytic (Schilling)leukemia. The monocytoid cells were labeled "reticulum" cells with the implication that they were related to the primitive hematopoietic reticulum cell.

5. The "reticulum" cell in the slide chamber differed from the monocyte inhaving a coarse nuclear chromatin pattern with clumping of chromatin,larger numbers of varying sized cytoplasmic granules, less ectoplasm, development of characteristic star-shaped macrophage forms without ectoplasmicveils, and in exhibiting a considerable ameboid motility as opposed to thesluggish veil waving of the monocyte.

6. Speculation as to the significance of the "reticulum" cell has been presented with the suggestion that this cell precedes the blast cell in hematopoiesis. In Naegeli leukemia, unknown factors may cause alterations in the typeof cell released from the marrow. There may also be shifts in emphasis betweenmyeloblast and pre-myeloblast proliferation which become reflected in thecells appearing in the peripheral blood.

Submitted on March 19, 1962 Accepted on May 28, 1962     

Two cases of carcinoma of the lung characterized by a bone marrow agar culture pattern resembling acute myeloid leukemia.

In vitro agar culture patterns of bone marrow cells in acute myeloid leukemia may show several growth patterns, including cultures where no colonies or clusters develop, cultures with varying numbers of clusters and no colonies, or colony and cluster formation with an extremely high ratio of clusters to colonies. Twelve cases of carcinoma of the lung are described, of which two show an in vitro growth pattern of cluster formation alone, characteristic of that seen in acute myeloid leukemia. The remaining ten patients showed slightly reduced colony numbers compared to normal.     

High risk subgroup of acute myelomonocytic leukemia (AMML) with orbito-ocular granulocytic sarcoma (OOGS) in Turkish children. Retrospective analysis of clinical, hematological, ultrastructural and therapeutical findings of thirty-three OOGS

Thirty-three patients presenting with orbito-ocular granulocytic sarcoma (OOGS) and acute myelomonocytic leukemia (AMML) were diagnosed in Turkish children from 1963 to 1983. OOGS, characterized by exophthalmos, chemosis and orbital masses, was observed in 33 (27.2%) of 121 AML patients compared with 41 children of AMML without ophthalmic tumors during the same period. Eye tumor and bone marrow aspirates were also studied under light and electron microscopies. The comparison of the hematological parameters did not indicate any statistical difference between the groups. Despite similar chemotherapy regimens administered to all patients, the mean survival time was 8.7 months in the OOGS group, which is significantly shorter compared to those without OOGS (28.6 months) (p less than 0.01). These cases may be classified as a "high risk" subgroup of childhood AMML.     

Electrophoretic and cytochemical characterization of alpha-naphthyl acetate esterases in acute myeloid leukemia: relationships with membrane receptor and monocyte-specific antigen expression

Alpha-naphthyl acetate esterases (ANAE) were examined by cytochemical and isoelectric focusing (IEF) techniques in 48 cases of acute myeloid leukemia that were classified by conventional morphological criteria. Four main types of ANAE isoenzyme patterns were found by IEF, and comparisons with the expression of membrane receptors (Fc-IgG and C3b) and monocyte-specific antigens (UCHM1, UCHALF, and E11) suggest relationships between ANAE isoenzyme synthesis and distinct myeloid maturational stages. The results further indicate that the blast cells of acute myelomonocytic leukemia (AMML) may represent an immature variant of monocytic leukemia (AMoL) and that morphological examination alone is inadequate in the assessment of monocytic differentiation in acute myeloid leukemias. Inhibition studies of cytochemical ANAE activity with sodium fluoride (NaF) show that the presence of NaF-sensitive or NaF-resistant ANAE enzymes is often unrelated to the diagnostic category of acute leukemia. The results of this study are examined in relation to current concepts of myeloid differentiation, and the application of these findings to the subclassification of acute myeloid leukemias is discussed.     

Hematopoietic progenitor cell colony growth differentiates chronic myelomonocytic leukemia from reactive monocytosis

In the absence of a cytogenetic abnormality or overt dysplasia, chronic myelomonocytic leukemia (CMML) may be difficult to be distinguished from reactive monocytosis. We have previously described a typical growth pattern in CMML patients, i.e., 'pseudonormal' colonies resembling granulocytic colonies but consisting entirely of monocytic cells when stained. To study the utility of the colony forming unit cell assay (CFU-C) as a diagnostic tool in patients with monocytosis, we analyzed a cohort of 48 consecutive patients referred to our institution with peripheral blood monocytosis. Thirty-six patients fulfilled the WHO criteria for CMML; 12 were diagnosed with reactive monocytosis. Of the patients with CMML, 28 showed pseudonormal growth with or without leukemic cluster growth, another four showed exclusively leukemic growth. None of the patients with reactive monocytosis showed either leukemic or pseudonormal growth. With a specificity of 100% and a sensitivity of 89%, the CFU-C assay has a unique potential to distinguish CMML from reactive monocytosis.     

In vitro and in vivo effects of deferoxamine in neonatal acute leukemia

A six week old infant with acute leukemia failed to attain remission with chemotherapy. Because we previously demonstrated that the iron chelator deferoxamine (DFO) has antiproliferative properties and modulatory effects on cell differentiation, a protocol was designed for in vitro study and for clinical use in the patient. At diagnosis, blast cells were morphologically undifferentiated, had nondiagnostic cytochemistry, showed an abnormal karyotype (t[4;11]), expressed markers of B cell lineage, and demonstrated C mu gene rearrangement. Tissue culture of marrow or blood cells yielded colonies of leukemic blasts. Increasing concentrations of DFO produced a dose-dependent suppression of patient's blast colony growth in vitro, and blasts within colonies showed a marked change in surface antigen expression from lymphoid to myelomonocytic markers, became monocytic in appearance, and developed intense staining for nonspecific esterase. When DFO was given intravenously to the patient as a single agent for 48 hours, blasts no longer expressed lymphoid antigens and became strongly positive for myelomonocytic markers, identical to the in vitro findings. Intravenous DFO halted rising peripheral blood blast cell numbers and allowed a several-fold increase in normal hematopoietic progenitor colony growth. When combined with low-dose cytosine arabinoside in the treatment protocol, DFO caused striking leukemic cytoreduction. Our findings indicate that DFO has antileukemic properties by virtue of its effects on proliferation and differentiation, and they prompt further experimental and clinical studies with this agent.     

Central nervous system involvement at presentation in acute granulocytic leukemia: A prospective cytocentrifuge study

We have undertaken a perspective study of the prevelance of the central nervous disease in acute granulocytic leukemia (AGL). Thirty-nine newly diagnosed patients with AGL underwent cytocentrifuge examination of cerebral spinal fluid. Seven of the 39 patients had blast cells in their cerebral spinal fluid. All seven of these patients had acute myelomonocytic leukemia (AMML). No patients with other variants of AGL demonstrated blast cells in their cerebral spinal fluid.Other high risk factors associated with meningeal infiltration were elevated serum lysozyme levels, high peripheral white blood cell count, low age, splemomegaly and the presence of infiltration in other organs.The admission rates for patients with meningeal leukemia were lower and the survival time was shorter than in both the 32 noninvolved patients and the noninvolved patients with AMML. We believe that a lumbar puncture is indicated in all patients with newly diagnosed AMML.     

Direct proliferative actions of stem cell factor on murine bone marrow cells in vitro: effects of combination with colony-stimulating factors.

Stem cell factor (SCF), the ligand for the c-kit protooncogene product, was able to stimulate blast cell and granulocytic colony formation by precursors from normal murine bone marrow. The blast cell colonies contained a high content of progenitor cells able to form macrophage and/or granulocyte colonies. Clone transfer studies, the secondary culture of colony cells, and the culture of populations freed of accessory cells all indicated a direct proliferative action of SCF. SCF receptors were present in high numbers on blast cells and in lower numbers on immature granulocytic, monocytic, and eosinophilic cells. Combination of SCF with granulocyte, granulocyte-macrophage, or multipotential colony-stimulating factors, but not macrophage colony-stimulating factor, resulted in enhancement of colony size. Granulocyte colony-stimulating factor enhanced cell proliferation initiated by SCF, but not vice-versa, and resulted in a 10-fold increase in colony cell numbers and a 7-fold increase in progenitor cells in blast colonies. No evidence was obtained that SCF, alone or in combination with granulocyte colony-stimulating factor, could stimulate self-generation by blast colony-forming cells.     

Acute myelomonocytic leukemia and the French-American-British classification

39 patients suffering from different subtypes of monocytic (M 5) and myelomonocytic (M 4) leukemia were analyzed retrospectively. In 8 cases a 'transitional myelomonocytic variant' was diagnosed; the leukemic cell in these patients is marked by morphological and cytochemical signs of monocytic and granulocytic precursors. As the correct diagnosis of this special subtype may be difficult, its place within the French-American-British (FAB) classification will be discussed.     

Interferons regulate the in vitro differentiation of multilineage lympho-myeloid stem cells in hairy cell leukemia.

In vitro 14-day cultures of peripheral blood mononuclear cells from hairy cell leukemia patients consistently showed the presence of hematopoietic stem cells giving rise to multilineage colonies containing a high proportion of lymphoid cells associated with the myeloid and erythroid progenitors. These stem cells are not the hairy cells but appear to be pluripotent lymphomyeloid primitive stem cells persisting in this leukemia. Interferon alpha c or beta 1 did not inhibit the growth of these colonies, as they did the growth of colonies of normal hematopoietic progenitors, but markedly decreased the ratio of lymphoid to myelomonocytic cells, by increasing the formation of monocytes and other nonlymphoid cell types in these multilineage colonies. Interferon gamma did not have the same effects on differentiation.     

Chronic myelomonocytic leukemia: from biology to therapy

Chronic myelomonocytic leukemia represents a distinct myelodysplastic syndrome in which an excess of monocytes is observed both in the blood and bone marrow of the patients. Whereas diagnosis is relatively easy, therapeutic design and efficacy is difficult and no treatment has to date provided complete or significant partial response. In vitro data suggest that the growth and differentiation of myelomonocytic progenitors may be altered inasmuch as monocytic or granulo-macrophagic colonies show spontaneous growth. Different entities may be observed: the childhood form, Juvenile Chronic Myelomonocytic Leukemia (JCML) shows in vitro a typical pattern with constitutive growth of only macrophagic colonies and hypersensitivity to GM-CSF; in the adult form at least two patterns may be observed one close to the JCML form and one more heterogeneous with absence of GM-CSF sensitivity and spontaneous growth of both CFU-GM and CFU-M colonies. Chemotherapy reduces all myeloid colonies in vitro whereas retinoic acid has a selective effect on monocytic colonies with a concomitant increase of CFU-G colonies forwarding an explanation for the correction of pancytopenia observed in some patients. Recent analysis of altered molecular pathways in this disease suggest a common disruption of intracelleular signalling pathways namely the Ras pathway and targetting for drugs with may selectively control or inhibit a constitutive activation may forward novel therapeutic perspectives.     

Human acute myelomonocytic leukemia: serologic studies with simian antisera.

Simian antisera to human leukemia cells were able to distinguish antigens specific for lymphocytic types of leukemia from those expressed on certain myeloid leukemia cells. In this investigation, cells from acute myelomonocytic leukemia patients (AMML) were examined for their membrane-associated leukemia antigens. Simian antisera to both lymphocytic and myelogenous leukemia cells lysed cells from AMML donors. Monkey antisera to AMML cells, by direct microcytotoxicity testing, were cytotoxic for cells from all AMML patients, as well as for cells of certain patients with myeloid leukemia. Cells from patients with lymphatic leukemia were nonreactive. However, absorption studies indicated an antigen present on cells from patients with chronic lymphocytic leukemia which cross-reacted with AMML cell antigens. Sequential analyses of the serologic reactivity of cells from AMML patients undergoing chemotherapy corresponded with the clinical course of the patient, even though there was little correlation between the percentage of blast cells present and the per cent cytotoxicity with the antisera. At certain times a higher percentage of seropositive cells could be detected over that seen on morphological evaluation. The estimation of leukemic cells by serologic means could aid in the diagnosis and management of AMML patients during chemotherapy.     

Differentiation induction of myeloid leukemia cells by glucocorticoid--the differentiation induction effect in vitro and in vivo

The effects of glucocorticoid on the differentiation of myeloid leukemia cells were examined. Dexamethasone at 10(-6)M or 10(-7)M revealed marked effects not only on leukemic blasts' survival but also on its' differentiation in vitro. In 10 of 17 cases of myeloid leukemia, the obvious morphological and functional differentiation induction effects were observed in vitro. The direction of differentiation were differed in leukemia cell lineage and in cases. Granulocytic differentiation in M2 cells, mono-macrophage differentiation in M5 cells and either granulocytic or monocytic differentiation in M4 cells were induced. A AML (M2), it's leukemia cells were induced into granulocytic pathway by dexamethasone in vitro, was treated with prednisolone (40 mg per day).Ara-C (15 mg per day). The increase in peripheral leukocyte count and the decrease in immature cells were observed simultaneously. The peripheral leukocytes mainly consisted of intermediate forms of granulocytes and Pelger-Hu?t like neutrophils probably originated from leukemia cells. After that course, abnormal clone was eliminated from bone marrow. A AMoL, it's leukemia cells were induced into macrophage like cells completely by dexamethasone in vitro, was treated with prednisolone (30 mg per day) and complete remission was obtained without passing through a hematological nadir. It is indicated that anti-tumor effects of glucocorticoid on myeloid leukemia cells are closely related to it's differentiation inducing effect and glucocorticoid can be used as the drug intending for the differentiation induction therapy of acute myeloid leukemia.     

Cytochemistry of acute promyelocytic leukemia (M3): leukemic promyelocytes exhibit heterogeneous patterns in cellular differentiation

Cytochemical investigation of leukemic promyelocytes from 25 cases of acute promyelocytic leukemia (M3) disclosed two major cellular differentiation categories: (1) the pure neutrophilic (N) type (16 cases) with strong myeloperoxidase (MPO) and naphthol-ASD chloroacetate esterase (Es-chl), but lacking the monocytic enzyme NaF-sensitive alpha-naphthyl butyrate esterase (Es-b), and (2) the mixed neutrophilic/monocytoid (N/M) type (seven cases) with strong Es-b as well as strong MPO, all cases exhibiting Es-dual (Es-b + Es-chl) positive cells. Two more cases with unusual phenotypes were noted: one with intense lysozyme activity but without Es-b and the other with toluidine blue-methachromasia and negative MPO. Promyelocytes from the control group, consisting of nine cases of t(8;21) M2 AML and ten cases with normal bone marrow, lacked such cytochemical heterogeneity. HL-60, an M3 cell line that can be induced to differentiate toward monocytic lineage in vitro, was almost negative for Es-b in the uninduced condition. Cytogenetically, eight cases of N type and five of N/M type had the t(15;17) abnormality. Thus at least two differentiation patterns were observed in M3 leukemia with fidelity (N type) and infidelity (N/M type) for normal granulocytic differentiation. In this series, there was no statistically significant difference in clinical features (remission rate and survival) between the two types. Our study suggests that the development of M3 leukemia is not exclusively restricted to the neutrophilic pathway, but more heterogeneously related to myelomonocytic differentiation.     

The in vitro growth pattern of human bone marrow in methylcellulose stimulated by different concentrations of conditioned medium

The proliferation of human bone marrow in methylcellulose stimulated by various concentrations of conditioned medium (CM) and observed at various intervals was studied. The growth kinetics of granulocytic aggregates was found to differ from monocytic clusters and colonies. Granulocytic aggregates showed a consistent and reproducible dose-response relationship; at day 7, the maximum number of granulocytic aggregates was found at 4% CM. At higher levels, the total number of aggregates decreased, while the number of cells per aggregate increased. The number of macrophage aggregates was far less, depending on the CM concentration. Photographic interval studies showed that at high concentrations of CM, clusters and colonies were formed earlier, but also coalesce to form one colony. Our results suggest that the proliferation kinetics of granulocytic aggregates are complex and preclude simple statements about sensitivity to colony-stimulating activity.     

Growth of clonogenic myeloblastic leukemic cells in the presence of human recombinant erythropoietin in addition to various human recombinant hematopoietic growth factors

The effects of human recombinant erythropoietin (rEpo) in the presence of other stimulators on the growth of clonogenic leukemic blast cells from ten Japanese patients with acute myeloblastic leukemia were studied with an in vitro leukemic blast colony assay in methylcellulose culture. With the addition of rEpo alone, no leukemic blast colony formation was stimulated in any of the cases examined. However, when rEpo and phytohemagglutinin lymphocyte-conditioned medium (PHA-LCM) were added to the culture simultaneously, in contrast to results with PHA-LCM alone, the number of leukemic blast colonies formed was significantly increased in two of the ten cases (P less than .01). These two cases were classified as M1 according to the French-American-British (FAB) classification. This enhancing effect of rEpo was observed with human recombinant granulocyte/macrophage colony-stimulating factor (rGM-CSF) or human recombinant interleukin-3 (rIL-3) but was not observed with human recombinant granulocyte CSF (rGCSF).     

Monoclonal antibodies to the human CSF-1 receptor (c-fms proto-oncogene product) detect epitopes on normal mononuclear phagocytes and on human myeloid leukemic blast cells

The first monoclonal antibodies (MoAbs) to epitopes in the extracellular domain of the human c-fms proto-oncogene product (receptor for the macrophage colony stimulating factor, CSF-1) were used with flow cytometric techniques to study receptor expression on normal human peripheral blood monocytes, bone marrow cells, and leukemic blasts. On normal cells CSF-1 receptors were restricted in their expression to cells of the mononuclear phagocyte lineage. CSF-1 receptors were detected on leukemic blasts from 15 (30%) of 50 children with acute myeloid leukemia, compared with four (15%) of 26 adults. By contrast, detectable CSF-1 receptors were uniformly absent on blasts from 19 children with acute lymphoblastic leukemia. CSF-1 receptors on normal monocytes and myeloid leukemia cells could be induced to downmodulate by incubation with either human recombinant CSF-1 or phorbol esters, confirming that the receptors had functional ligand- binding sites and responded to transmodulation by inducers of protein kinase C. The numbers of receptors per cell and the percentage of positive cases were highest for leukemic blasts with cytochemical and morphological features of monocytes. However, CSF-1 receptors were also detected on a subset of leukemic blast cells with features of granulocytic differentiation (FAB subtypes M1 through M3). Southern blotting analyses of DNA from 47 cases of acute myeloid leukemia demonstrated no rearrangements within the 32 kb of genomic sequences that contain CSF-1 receptor coding exons or in the 50 kb upstream of the first coding exon. Analysis of the upstream region of the c-fms locus revealed that sequences representing the terminal 112 untranslated nucleotides of c-fms mRNA map 26 kb 5' to the first coding exon, suggesting that at least one c-fms promoter is separated from the receptor coding sequences by a very long intron. Whereas expression of the CSF-1 receptor in myeloid leukemic blasts is not restricted to cells with monocytic characteristics, the apparently aberrant pattern of receptor synthesis in a subset of cases with granulocytic features appears not to be due to chromosomal rearrangements within 50 kb upstream of sequences encoding the receptor.