Clones Of Leukemic Cells Research Articles

In Vivo Control of Differentiation of Myeloid Leukemic Cells by Recombinant Granulocyte-Macrophage Colony-Stimulating Factor and Interleukin 3

The normal myeloid hematopoietic regulatory proteins include one class of proteins that induces viability and multiplication of normal myeloid precursor cells to form colonies (colony-stimulating factors [CSF] and interleukin 3 [IL-3], macrophage and granulocyte inducing proteins, type 7 [MGI-1]) and another class (called MGI-2) that induces differentiation of normal myeloid precursors without inducing cell multiplication. Different clones of myeloid leukemic cells can differ in their response to these regulatory proteins. One type of leukemic clone can be differentiated in vitro to mature cells by incubating with the growth-inducing proteins granulocyte-macrophage (GM) CSF or IL-3, and another type of clone can be differentiated in vitro to mature cells by the differentiation-inducing protein MGI-2. We have now studied the ability of different myeloid regulatory proteins to induce the in vivo differentiation of these different types of mouse myeloid leukemic clones in normal and cyclophosphamide-treated mice. The results show that in both types of mice (a) the in vitro GM-CSF- and IL-3-sensitive leukemic cells were induced to differentiate to mature cells in vivo in mice injected with pure recombinant GM-CSF and IL-3 but not with G-CSF, M-CSF, or MGI-2; (b) the in vitro MGI-2-sensitive leukemic cells differentiated in vivo by injection of MGI-2 and also, presumably indirectly, by GM-CSF and IL-3 but not by M-CSF or G-CSF; (c) in vivo induced differentiation of the leukemic cells was associated with a 20- to 60-fold decrease in the number of blast cells; and (d) all the injected myeloid regulatory proteins stimulated the normal myelopoietic system. Different normal myeloid regulatory proteins can thus induce in vivo terminal differentiation of leukemic cells, and it is suggested that these proteins can have a therapeutic potential for myeloid leukemia in addition to their therapeutic potential in stimulating normal hematopoiesis.

Role of different normal hematopoietic regulatory proteins in the differentiation of myeloid leukemic cells.

There are 4 different normal myeloid hematopoietic cell growth-inducing proteins MGI-1 (CSF or IL-3) that induce normal precursor cells to multiply and form clones containing only macrophages (MGI-1M = M-CSF = CSF-1), only granulocytes (MGI-1G = G-CSF), both granulocytes and macrophages (MGI-1GM = GM-CSF), or granulocytes, macrophages, eosinophils, mast cells, megakaryocytes and erythroid cells (interleukin-3) (IL-3). There is another type of normal myeloid regulatory protein (MGI-2) with no MGI-1 (CSF or IL-3) activity which can induce differentiation of normal myeloid precursors and certain clones of myeloid leukemic cells. The present results with MGI-2 and pure recombinant MGI-1G, MGI-1GM and IL-3 have shown that different clones of myeloid leukemic cells can be induced to differentiate by different hematopoietic regulatory proteins. One type of leukemic clone is induced to differentiate to mature cells only by MGI-2 and is partially differentiated by MGI-1G, a second type is differentiated only by MGI-1GM or IL-3, and other workers have found a third type that is differentiated only by MGI-1G. The presence of surface receptors does not necessarily make leukemic cells differentiation-competent for these hematopoietic regulatory proteins. All 4 types of MGI-1 (CSF or IL-3) induce endogenous synthesis of MGI-2 in normal myeloid precursor cells. It is suggested that, in addition to their potential therapeutic effect on the development of normal hematopoietic cells, MGI-2, MGI-1G, MGI-1GM and IL-3 all have the potential for differentiation-directed therapy of leukemia in leukemic cells that can be differentiated by one of these normal hematopoietic regulatory proteins.

Blood lymphocyte characteristics as predictors of prognosis in chronic lymphocytic leukemia of B-cell type.

The prognostic information of blood lymphocyte characteristics and clinical findings was assessed in 62 patients with chronic lymphocytic leukemia of B cell type. Bivariate and multivariate survival analyses were performed using age, Rai stage, surface membrane immunoglobulin (smIg) isotype pattern of the leukemic clone, total lymphocyte counts, numbers of proliferating lymphocytes and T cell subpopulations. Rai stages III and IV, high numbers of blood lymphocytes in S-phase (S+) and sm mu isotype were found to be partly independent factors predicting short therapy-free survival. Patients with a sm mu+ leukemic cell clone had a shorter therapy-free and total survival compared to those with sm mu+/delta+ and sm delta+ leukemic cells. Moreover, patients with high numbers of blood S+ lymphocytes had a shorter therapy-free and total survival compared to those with few S+ cells. These prognostic variables were valid also in patients with a low tumour burden (Rai stages 0, I and II) and may thus be of clinical importance as a guideline for therapeutic intervention.

Appearance of a novel type of ganglioside (GD1 alpha) in a differentiation-resistant clone of mouse myeloid leukemia cells, M1-R1.

Glycolipid compositions of three mouse myeloid leukemia cell clones, two that are sensitive to differentiation inducers (M1-T22 and M1-S1) and one that is differentiation-resistant (M1-R1), have been compared. The T22 and S1 clones contained glucosylceramide (GlcCer), lactosylceramide (LacCer) and gangliotriaosylceramide (Gg3Cer) as the major neutral glycolipids. The differentiation resistant clone, R1, was characterized by the appearance of globotriaosylceramide (Gb3Cer) and a decrease of Gg3Cer. There was a distinct difference in the ganglioside profile between the differentiation-inducible and -resistant clones: T22 and S1 cells contained no detectable amounts of ganglioside, whereas six different gangliosides were detected in the R1 clone. These gangliosides were isolated and identified as GM3, GM2, GM1a, GD1a, GM1b, and a unique disialoganglioside, GD1 alpha, having the following structure: (formula; see text) Based on these comparative studies, the relationship between the glycolipid composition and the differentiation potential of leukemia cells is discussed.

Selection and characterization of mycophenolic acid-resistant leukemia cells.

We isolated four mycophenolic acid (MA) -resistant clones (MA0.4, MA2, MA5, MA20) of murine leukemia (L1210) cells which were 2- to 125-fold more resistant than the parent cells to MA and had a 4- to 50-fold increase in the activity of the enzyme inosine monophosphate dehydrogenase (IMPDase). The MA-resistant phenotype was unstable after passage of MA0.4, MA2, and MA5 without MA, but stable after passage of MA20 without MA. All MA-resistant cell lines lost IMPDase activity after passage without MA. However, only MA20 lost IMPDase activity after passage with MA. The enzyme from all cell lines had similar kinetic parameters. The levels of a single polypeptide of approximately 57,000 daltons was increased in MA5, and the levels decreased after passage of the cells without MA. These results indicate that three of the selected cell lines are resistant to MA because of an increase in the amount of enzyme IMPDase, while the stability of the resistant phenotype of MA20 and its less than expected IMPDase activity that this cell line may have a second mode of resistance.

Regulation of cell-surface receptors for hematopoietic differentiation-inducing protein MGI-2 on normal and leukemic myeloid cells.

The normal myeloid hematopoietic regulatory proteins include 4 different growth-inducing proteins (IL-3, MGI-1GM = GM-CSF, MGI-1G = G-CSF, and MGI-1M = M-CSF = CSF-1). There is also another type of normal myeloid regulatory protein (MGI-2) with no MGI-1 (CSF or IL-3) activity, which can induce differentiation of normal myeloid precursors and certain clones of myeloid leukemic cells. Studies on the binding of MGI-2 to differentiation-competent (D+) and differentiation-defective (D-) clones of mouse myeloid leukemic cells and to normal cells indicate that: (1) D+ clones of myeloid leukemic cells had about 2,500 high-affinity surface receptors per cell, like mature normal myeloid cells, and the bound MGI-2 was rapidly internalized with its cell-surface receptors at 37 degrees C causing down-regulation of MGI-2 receptors in both the normal and leukemic cells; (2) in some D- clones, the number and internalization of MGI-2 receptors were similar to those of D+ clones whereas other D- clones had only 0-100 MGI-2 receptors per cell; (3) normal thymus and lymph-node lymphocytes and T lymphoma cells did not show detectable MGI-2 receptors; (4) there was an independent expression of receptors for MGI-2 and for the 4 myeloid growth-inducing proteins on different clones of myeloid leukemic cells; and (5) none of the 4 myeloid growth-inducing proteins IL-3, MGI-1GM, MGI-1G, or MGI-1M, inhibited binding of MGI-2 to its receptors. The cytotoxic proteins lymphotoxin and tumor necrosis factor did not induce differentiation of the mouse myeloid leukemic cells and also did not inhibit binding of MGI-2 to its receptors. These results show that the myeloid differentiation-inducing protein MGI-2 binds to cell-surface receptors that are different from the receptors for the 4 myeloid growth-inducing proteins and these cytotoxic proteins.

Analyses of phenotype and genotype in acute lymphoblastic leukemias at first presentation and in relapse

As a clue to the cellular origin of leukemic populations in relapse we analyzed 11 cases of acute lymphoblastic leukemia (ALL) by immunological and molecular genetic approaches. Blast cells obtained from both initial diagnosis and relapse were immunophenotyped using a variety of monoclonal antibodies; simultaneously we hybridized Southern blots of respective cell samples to immunoglobulin (Ig) heavy and light chain as well as to T-cell receptor beta-chain (T beta) sequences. While similar phenotypes were observed in both states of nine cases, comparison of Ig gene rearrangements revealed clonal variations, ie, appearance of an evoluted or novel leukemic cell clone in relapse beside identical leukemic populations in both states. One pre-T (ALL) patient, presenting with germline configuration of T beta gene sequences at diagnosis, exhibited a rearrangement of T beta gene sequences in recurrent disease. Another patient displayed T-ALL phenotype and T beta gene rearrangement at diagnosis but relapsed with a very immature phenotype and germline configuration for T beta sequences. Our results emphasize the value of molecular analyses in order to unravel the nature of leukemic relapse.

Analyses of Phenotype and Genotype in Acute Lymphoblastic Leukemias at First Presentation and in Relapse

AbstractAs a clue to the cellular origin of leukemic populations in relapse we analyzed 11 cases of acute lymphoblastic leukemia (ALL) by immunological and molecular genetic approaches. Blast cells obtained from both initial diagnosis and relapse were immunophenotyped using a variety of monoclonal antibodies; simultaneously we hybridized Southern blots of respective cell samples to immunoglobulin (Ig) heavy and light chain as well as to T-cell receptor β-chain (Tβ) sequences. While similar phenotypes were observed in both states of nine cases, comparison of Ig gene rearrangements revealed clonal variations, ie, appearance of an evoluted or novel leukemic cell clone in relapse beside identical leukemic populations in both states. One pre-T (ALL) patient, presenting with germline configuration of Tβ gene sequences at diagnosis, exhibited a rearrangement of Tβ gene sequences in recurrent disease. Another patient displayed T-ALL phenotype and Tβ gene rearrangement at diagnosis but relapsed with a very immature phenotype and germline configuration for Tβ sequences. Our results emphasize the value of molecular analyses in order to unravel the nature of leukemic relapse.

Reduced maturation of friend virus in adhesive mutants of friend leukemia cells

The replication of Friend Leukemia virus (FLV) has been investigated in adhesive clones (FF) of Friend Leukemia cells which were selected via cultivation on top of human fibroblast monolayers. In these adhesive clones a shut-down of FLV production is observed under conditions of culture confluency; this finding is not due either to a reduced number of cell divisions nor to a defective expression of FLV genome as assessed by Northern blot and immunofluorescence studies. Ultrastructural studies showed that virus budding and release into the medium is not detectable under these conditions. Conversely, in confluent FF cell monolayers abundant imperfect type-A enveloped particles were visible, possibly originating from stacks of granular endoplasmic reticulum with thickened membranes. It is postulated that the reduced virus production in adhesive FF monolayers is due to as yet undetermined events taking place during virus maturation at a time coincident with that of cell-cell adhesion under conditions of culture confluency.

DNA aneuploidy in children with relapsed acute lymphoblastic leukemia as measured by flow cytometry.

An aneuploid DNA stem line has been detected by flow cytometric measurements in 17 (29%) out of 59 children entered in the BFM 83 pilot study for ALL relapse. Of 17 DNA aneuploidies, 15 were hyperdiploid. Euploidy was observed in 28 of 34 patients with an early relapse, whereas 11 of 25 children suffering a late recurrence of disease showed aneuploid DNA stem lines. In contradistinction to ALL relapse, a significantly higher frequency (38%) of pretreatment DNA aneuploidy was measured in 376 newly diagnosed patients of the BFM trials. Our findings may reflect the impact of therapy on leukemic cell clones and their relapse pattern.

Regulation of cell surface receptors for different hematopoietic growth factors on myeloid leukemic cells.

There are clones of myeloid leukemic cells which are different from normal myeloid cells in that they have become independent of hematopoietic growth factor for cell viability and growth. The ability of these clones to bind three types of hematopoietic growth factors (MGI-1GM = GM-CSF, IL-3 = multi-CSF and MGI-1M = M-CSF = CSF-1) was measured using the method of quantitative absorption at 1 degree C and low pH elution of cell-bound biological activity. Results of binding to normal myeloid and lymphoid cells were similar to those obtained by radioreceptor assays. The results indicate that the number of receptors on different clones of these leukemic cells varied from 0 to 1,300 per cell. The receptors have a high binding affinity. Receptors for different growth factors can be independently expressed in different clones. There was no relationship between expression of receptors for these growth factors and the phenotype of the leukemic cells regarding their ability to be induced to differentiate. The number of receptors on the leukemic cells was lower than on normal mature macrophages. Myeloid leukemic cells induced to differentiate by normal myeloid cell differentiation factor MGI-2 (= DF), or by low doses of actinomycin D or cytosine arabinoside, showed an up-regulation of the number of MGI-1GM and IL-3 receptors. Induction of differentiation of leukemic cells by MGI-2 also induced production and secretion of the growth factor MGI-1GM, and this induced MGI-1GM saturated the up-regulated MGI-1GM receptors. It is suggested that up-regulation of these receptors during differentiation is required for the functioning of differentiated cells.

A new HLA-linked T cell membrane molecule, related to the beta chain of the clonotypic receptor, is associated with T3.

The 38 kD molecule is noncovalently associated with beta 2 microglobulin (beta 2m)-free HLA heavy chain-like molecule, and thus forms a second heterodimer distinct from the clonotypic alpha/beta T cell receptor expressed by the same clone of leukemia cells. This second heterodimer (38 kD/HLA) is variably expressed and appears to be associated with the T3 molecule. We suggest, therefore, that it has a functional role in T cell activation.

Potentiation by 1-α,25-0ihydroxyvitamin D3 of Cytotoxicity to HL-60 Cells Produced by Cytarabine and Hydroxyurea

A short (4-hr) exposure to 1-4 X 10(-7) M 1,25-dihydroxyvitamin D3 [(1,25(OH)2D3); 1-alpha,25-dihydroxycholecalciferol] induced transient differentiation in a clone (R2AB2) of human promyelocytic leukemia cells (HL-60) but caused no permanent growth impairment and no detectable cytotoxicity. This treatment with 1,25(OH)2D3 also produced an inhibition of DNA synthesis that was promptly reversed when 1,25(OH)2D3 was removed. When such treatment with 1,25(OH)2D3 immediately followed a sublethal exposure to drugs that inhibit DNA synthesis, including the cancer chemotherapeutic agents cytarabine and hydroxyurea, the proportion of HL-60 cells lethally damaged was increased. This finding was demonstrated by morphologic evidence of cell damage and disintegration, an increased permeability to trypan blue, loss of cells from culture, and a reduced clonogenic potential of the treated cells. Exposure to 1,25(OH)2D3 before treatment with a cytotoxic agent had a slightly protective rather than a damaging effect. These observations suggest that the presence of 1,25(OH)2D3 markedly reduces the capacity of HL-60 cells to repair DNA damage or to reduce the intracellular concentration of cytotoxic agents.

Establishment of a Hairy Cell Leukemia Cell Line Carrying Tac Antigen and Phagocytic Activity With B-Cell Characteristics<xref ref-type="fn" rid="FN2">2</xref>

A hairy cell leukemia cell line designated "Hair-M" was established in a suspension culture derived from the peripheral blood of an 86-year-old Japanese male with a diagnosis of hairy cell leukemia. The Hair-M cells were identified as having prominent hair-like cytoplasmic projections by examination with phase-contrast and scanning electron microscopy. These cells displayed ruffled membranes and stublike microvilli similar to those observed on the surfaces of cells in the peripheral blood of the patient. Immunologic and cytochemical studies on the Hair-M cells confirmed derivation from the clone of the patient's leukemia cells. Although the cultured Hair-M cells had definite B-cell characteristics, such as IgG kappa-chains on the surface and in cytoplasm, they also demonstrated Tac antigen, which is usually expressed on activated T-cells, and myelomonocyte antigens determined by OKM-1 and MCS-1 monoclonal antibodies. Other cell surface markers, including E(-), IgGFc(-), IgMFc(-), C3R(+), Ia-like antigen(+), OKT9(+), OKT10(+), and terminal deoxynucleotidyl transferase(-), were detected; no Epstein-Barr virus-determined nuclear antigen was detected. The karyotype of the Hair-M cells was determined to be 46XY with -11, -14, and two marker chromosomes. The Hair-M cells also had phagocytic activity to rabbit anti-human IgG serum-coated polyacrylamide gel particles.

Regulation of in-vivo differentiation of myeloid leukemic cells by antigen-specific helper T lymphocytes

There are clones of myeloid leukemic cells that can be induced to differentiate in vitro and in vivo by normal macrophage and granulocyte differentiation-inducing protein MGI-2 ( = DF). The differentiation of these myeloid leukemic cells in vivo is regulated by a cell mediated immune response which requires T lymphocytes. We now show that differentiation of myeloid cells in vivo can be induced by antigen-specific helper T lymphocytes and that this is associated with the ability of the helper T cells to produce myeloid cell differentiation-inducing protein MGI-2. Antigen specific helper T cells can accumulate at a site that contains the antigen. It is suggested that migration in response to antigen of helper T cells producing differentiation factors may play an important role in inducing in vivo differentiation of leukemic cells.

Control of in-vivo differentiation of myeloid leukemic cells— V. Regulation by response to antigen

Regulation of in-vivo differentiation of myeloid leukemic cells by response to antigen was analysed with different clones of mouse myeloid leukemic cells and human myeloid leukemic cells (HL-60). Differentiation was studied in diffusion chambers implanted into the peritoneal cavity of mice and the antigens used were bovine serum albumin and chicken ovalbumin. It is shown that the presence of either of these antigens in the diffusion chambers can induce differentiation in MGI + D + mouse and human myeloid leukemic cells, and that pre-immunization with antigen enhanced this in-vivo differentiation. This enhancement showed immunological specificity and was transferred from immunized to non-immunized mice by spleen cells enriched for T lymphocytes. In contrast to these results with MGI + D + clones of myeloid leukemic cells, clones of WEH1-3B myeloid leukemic cells were induced to differentiate in vivo to the same extent either in the presence or absence of antigen. The results indicate: (1) that in-vivo differentiation of MGI + D + clones of myeloid leukemic cells can be induced by response to antigen and (2) that in vivo differentiation of different clones of myeloid leukemic cells can be regulated in different ways.

Control of in vivo differentiation of myeloid leukemic cells. IV. Inhibition of leukemia development by myeloid differentiation-inducing protein.

It is shown that a 5-day schedule of two injections per day of the myeloid differentiation-inducing protein MGI-2 inhibited the in vivo development of leukemia in SL and SJL/J mice with different syngeneic MGI+D+ clones of myeloid leukemic cells. With this schedule of treatment high levels of MGI-2 were maintained in the serum for long periods. In contrast to these results with MGI-2, the same schedule of injections of the myeloid growth-inducing protein MGI-I did not affect the in vivo development of leukemia in mice with MGI+D+ myeloid leukemic cells, but stimulated normal myelopoiesis in the bone marrow. Different forms of MGI-I including MGI-IM and MGI-IG had different serum half-lives, and the form of MGI-I with the shortest serum half-life showed the smallest in vivo effect on normal myelopoiesis. MGI-2 injections did not inhibit the in vivo development of differentiation-defective WEHI-3B myelomonocytic leukemic cells or YAC lymphoma cells. The results indicate that the in vivo inhibitory effect of MGI-2 on the development of myeloid leukemia correlated with its differentiation-inducing potential on the leukemic cells. It is concluded that this approach of inhibiting leukemia development by inducing differentiation should also be applied to human leukemic patients, whose cells have been shown to be inducible for differentiation in culture by human MGI-2 or by other differentiation-inducing compounds.

Developmental potential of myeloid leukemia cells injected into midgestation embryos

Cells from a clone of mouse myeloid leukemic cells that can be induced to differentiate in vitro to mature cells by the normal macrophage- and granulocyte-inducing protein, MGI-2, were injected into mouse embryos at 10 days gestation. The leukemic cells, derived from an SJL J mouse, were microinjected into the placentase of C3HeB fetuses and the viable progeny were tested for chimerism by analysis of glucose phosphate isomerase isozymes. Fifty-five percent out of 201 viable progeny died prior to weaning due to tumors derived from the injected cells. Of the remaining 91 apparently healthy adult animals, 2 had chimeric populations. One mouse had a chimeric population of granulocytes and the other mouse a chimeric population of macrophages. The animal with a chimeric population of macrophages was chimeric at 1 and 2 months of age and had lost any detectable donor derived contribution by the age of 3 months. The chimeric granulocyte population in the other animal was still stable at 3 months. The myeloid leukemic cells injected into midgestation embryos thus participated in the development of two different cell types in apparently healthy adult animals. Our results indicate that malignant cells of more restricted developmental potential than teratocarcinoma cells may participate in normal development. It remains to be determined whether this participation in normal development was due to normal differentiation of the malignant cells, or the production of nonmalignant segregants derived from the malignant cells.

Coupling of growth and differentiation in normal myeloid precursors and the breakdown of this coupling in leukemia.

Normal myeloid precursors are dependent on the macrophage and granulocyte growth-inducing protein MGI-1 for cell viability and multiplication. MGI-1 also induces production of the differentiation-inducing protein MGI-2, and this induction of a differentiation-inducing protein by a growth-inducing protein provides a mechanism for the normal coupling of growth and differentiation. It is shown that this induction of MGI-2 by MGI-1 occurs in the myeloid precursors and not in some other cells in the normal bone marrow, that the induced MGI-2 can be detected 6 h after the addition of MGI-1, and that MGI-2 can be induced in these cells by purified MGI-1. There are clones of myeloid leukemic cells that no longer require MGI-1 for cell viability and multiplication, but in which this requirement for MGI-1 can be restored after induction of differentiation by MGI-2. A similar concentration of MGI-1 was required for the optimum induction of growth in these differentiating leukemic cells and in normal myeloid precursors. In the presence of MGI-1 these differentiating leukemic cells multiplied and then lost their differentiation-associated properties. In contrast to normal myeloid cells, MGI-1 did not induce MGI-2 in the MGI-1 requiring differentiating myeloid leukemic cells. This lack of induction of MGI-2 by MGI-1 occurred in cells cultured in serum-containing or serum-free-medium, and can explain the loss of differentiation-associated properties. The results indicate that there has been a genetic breakdown of the normal coupling mechanism between growth and differentiation in these leukemic cells so that MGI-1 can no longer induce MGI-2.

Prolongation by interferon preparation of the survival time of mice implanted with differentiation-inducible mouse myeloid leukemia cells

The effect of L-cell interferon (IFN) preparation on the survival times of mice implanted with two different clones (T-22 and R-4) of mouse myeloid leukemic MI cells were examined. T-22 cells, but not variant R-4 cells, can be induced to differentiate in vitro or in vivo into macrophages and granulocytes. In vitro growth of R-4 cells was markedly suppressed by IFN, but that of T-22 cells was resistant to IFN. The survival times of mice with implanted T-22 cells were prolonged by treatment with IFN but those of mice with implanted R-4 cells were not.