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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The study of myelopoietic maturation arrest in acute myeloblastic leukemia (AML) has been eased by availability of the human recombinant hemopoietic growth factors, macrophage colony stimulating factor (M-CSF), granulocyte-(G-CSF), granulocyte-macrophage-(GM-CSF) and multilineage stimulating factor (IL-3). Nonphysiological expansion of the leukemic population is not due to escape from control by these factors. Proliferation in vitro of AML cells is dependent on the presence of one or several factors in most cases. The pattern of factor-dependency does not correlate with morphological criteria in individual cases, and may thus offer a new tool for classification of AML. Overproduction of undifferentiated cells is not due to abnormal expression of receptors for the stimulating factors acting at an immature level. Rather, autocrine secretion of early acting lymphokines maintains proliferation of the leukemic clone. When looking at causes of leukemic dysregulation, yet undefined inhibitors of differentiation probably are of equal importance as dysequilibrated stimulation by lymphokines.
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PMID:Hematopoietic growth factors and human acute leukemia. 326 16

Colony stimulating factors (CSFs) are produced by a variety of cell types, including T-lymphocytes (T cells) and mononuclear phagocytes; both cell types are known to cooperatively interact to elaborate CSFs, although the specific cellular source of CSF species and mechanisms of intercellular communications in this regard are poorly understood. In this report, we investigate the specific origin of various CSF species in peripheral blood mononuclear cells (PBMC), purified T-lymphocyte and monocyte (Mo) populations. Furthermore, we assess the conditions required for stimulation of purified cell cultures to express CSF messenger RNAs (mRNAs) and proteins. In the absence of exogenous activation stimuli, human PBMC, T cells and Mo failed to produce transcripts for CSF for macrophages (M-CSF or CSF-1), for granulocytes (G-CSF), for granulocytes/macrophages (GM-CSF), and for multilineage CSF (multi-CSF or Il-3). However, after stimulation with phorbol myristate acetate (PMA) and phytohemagglutinin (PHA), mRNAs for M-, G-, GM-CSF, and multi-CSF became detectable in PBMC as early as 6 hours after initiation of cultures. Identical culture conditions resulted in synthesis of G-, and M-CSF mRNA by Mo, whereas T-lymphocytes produced GM-CSF and multi-CSF mRNA. More physiologically, when Mo were activated with interferon (IFN)-gamma or tumor necrosis factor-alpha (TNF-alpha) and T-lymphocytes were stimulated in an Mo-independent pathway, that is via triggering of the 50 kd sheep erythrocyte receptor protein employing monoclonal antibodies (mo ab) to the Tll-2- and Tll-3- defined epitopes, similar kinetics of mRNA expression were obtained. Similarly, when interleukin-1 (Il-1) receptive T cells were stimulated with Il-1, T cells transcribed functionally active GM-CSF and multi-CSF. Maximum peak activity of GM-, G-, and M-CSF protein secretion was identical for all CSF species investigated, and occurred in culture 48-72 hours after specific induction. Constitutive expression of CSFs not found in unactivated normal hematopoietic cells was, however, frequently observed in blast cell populations of patients with acute myeloblastic leukemia. Of 49 AML samples, 15 revealed G-CSF transcripts; 11, GM-CSF mRNA; and 6 samples synthesized M-CSF mRNA. Employing specific bioassays, 12 of 15 G-CSF-mRNA-producing cell populations, 8 of 11 GM-CSF-mRNA-producing cell populations, and 1 of 6 M-CSF-mRNA-synthesizing samples, demonstrated release of the respective functionally active CSFs into their culture supernatants.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Regulation of gene expression of M-, G-, GM-, and multi-CSF in normal and malignant hematopoietic cells. 326 79

Blast cell populations of forty nine individuals with acute myeloblastic leukemia (AML) were investigated for constitutive expression of genes for various hematopoietic growth factors. Fifteen samples constitutively exhibited messenger (m) RNA for colony stimulating factor for granulocytes (G-CSF). Eleven AML specimens produced mRNA specific for CSF for granulocyte and macrophages (GM-CSF). When probed for CSF for macrophages (M-CSF or CSF-1) specific hybridization signals became detectable in six samples. Five out of six blast cell populations transcribing M-CSF, synthesized G-, and GM-CSF mRNA's simultaneously, whereas another five leukemias transcribed G-, and GM-CSF genes exclusively. Furthermore, when specific bioassays were performed to detect secretion of biologically active CSF proteins by these leukemic blast samples, twelve out of fifteen G-CSF mRNA producing cell populations, eight out of eleven GM-CSF mRNA producing cell populations and one out of six M-CSF mRNA synthesizing samples, demonstrated release of the respective, functionally active CSF's into their culture supernatants. Our results show that gene transcription and protein secretion of hematopoietic growth factors are features that are frequently detected in leukemic myeloid blast cells and involve G-, GM-, and M-CSF. With respect to recent findings of receptiveness of leukemic colony forming cells (L-CFC) for proliferative stimuli provided by various hematopoietic growth factors, our findings point out a potential role of autocrineously produced CSF's in the pathophysiology of autonomous proliferation in AML.
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PMID:Constitutive expression of hematopoietic growth factor genes by acute myeloblastic leukemia cells. 326 64

Cells of the factor-dependent hemopoietic cell line FDC-P1 become leukemic when injected intravenously to irradiated syngeneic mice. An analysis of 117 cell lines derived from 17 such leukemic mice showed that they displayed different patterns of growth in vitro ranging from full autonomy to absolute dependency on stimulation by granulocyte-macrophage colony stimulating factor (GM-CSF) or multipotential colony stimulating factor (multi-CSF). In contrast to parental FDC-P1 cells, even the factor-dependent variant cell lines were tumorigenic in vivo. The behavior of these latter cell lines could not be explained by hyperresponsiveness to CSFs or prolonged survival in the absence of CSFs. Conditioned media and cell lysates from leukemic cell lines from 8 animals contained variable levels of GM-CSF or multi-CSF. Proliferation of a GM-CSF-producing cell line was inhibited by anti-GM-CSF antibody, while both the parental FDC-P1 line and a leukemic line secreting multi-CSF remained unaffected. The patterns of growth in vitro of the leukemic cells tended to correlate with the amounts of CSFs produced. The observations show that leukemic transformation of FDC-P1 cells in vivo is frequently linked to autogenous production of hemopoietic growth factors. The range of abnormal in vitro growth patterns observed includes those typical of human acute myeloid leukemia, and the in vivo transformation model may be useful in analyzing the mechanisms leading to the development of this human disease.
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PMID:In vitro growth patterns and autocrine production of hemopoietic colony stimulating factors: analysis of leukemic populations arising in irradiated mice from cells of an injected factor-dependent continuous cell line. 328 21

Like their normal counterparts, leukemic blasts have recently been shown to respond to hemopoietic growth factors in both suspension culture and in semisolid media. In the present study, we have evaluated the proliferative response of 35 AML cases to colony-stimulating factors (CSFs) containing conditioned media derived from the human cell lines GCT, 5637, MO and MG U87, and to human recombinant IL-1 (rh-IL1), IL-3 (rhIL-3), GM-CSF (rhGM-CSF) and G-CSF (rhG-CSF). In the great majority of cases, an increase of 3H-thymidine (3H-TdR) uptake was obtained in response to at least one conditioned medium. The labeling index (LI) and the growth fraction (GF), evaluated in a restricted group of cases, were also increased by the growth factors, suggesting that they act by recruiting leukemic cells in cycle from the resting compartment. The ability of blast populations to form colonies was also studied. Conditioned media were found to induce or significantly increase the clonogenic capacity in 20 cases out of 22. The response of leukemic cells to human recombinant CSFs and rhIL-1, used alone or in combination, was also assayed. The results, in agreement with those obtained with conditioned media, show that each leukemic case displays a different pattern of response to CSFs, and that optimal growth conditions must be individually assessed. The possibility of increasing the fraction of cycling cells in AML populations may represent a way to render them more sensitive to cytostatic agents, with a view to new therapeutic strategies.
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PMID:Induction of proliferation of acute myeloblastic leukemia (AML) cells with hemopoietic growth factors. 328 16

By in situ chromosomal hybridization, the GM-CSF and FMS genes were localized to human chromosome 5 at bands q23 to q31, and at band 5q33, respectively. These genes encode proteins involved in the regulation of hematopoiesis, and are located within a chromosome region frequently deleted in patients with neoplastic myeloid disorders. Both genes were deleted in the 5q-chromosome from bone marrow cells of two patients with refractory anemia and a del(5)(q15q33.3). The GM-CSF gene alone was deleted in a third patient with acute nonlymphocytic leukemia (ANLL) who has a smaller deletion, del(5)(q22q33.1). Leukemia cells from a fourth patient who has ANLL and does not have a del(5q), but who has a rearranged chromosome 5 that is missing bands q31.3 to q33.1 [ins(21;5)(q22;q31.3q33.1)] were used to sublocalize these genes; both genes were present on the rearranged chromosome 5. Thus, the deletion of one or both of these genes may be important in the pathogenesis of myelodysplastic syndromes or of ANLL.
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PMID:Evidence for the involvement of GM-CSF and FMS in the deletion (5q) in myeloid disorders. 348 37

Proliferation of acute myeloblastic leukemia (AML) cells in vitro is limited in most cases to a small subset of blasts that have several properties of stem cells. These leukemic colony-forming cells (AML-CFU) generally require addition of exogenous growth factors for proliferation in agar or methylcellulose. These factors can be supplied by media conditioned by phytohemagglutinin-stimulated normal leukocytes or by CSF-secreting tumor cell lines. However, the exact factor or factors required for stimulation of AML-CFU growth have not been defined. We compared the AML-CFU stimulatory activity of a human recombinant GM-CSF with that of GCT-CM, Mo-CM, and the PHA-leukocyte feeder system in 15 cases of AML. In each of the 12 cases that required exogenous growth factors for maximum AML-CFU growth, recombinant GM-CSF could replace either GM-CSF or Mo-CM, and could partially replace the PHA-leukocyte feeder system. These results indicate that this GM-CSF is a growth promoter of AML-CFU in these culture systems.
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PMID:Effects of recombinant human GM-CSF on proliferation of clonogenic cells in acute myeloblastic leukemia. 348 12

Three cases of acute myeloblastic leukemia (AML) were identified in which clonogenic cells proliferated autonomously in vitro. Cells from two of these cases were found to secrete a colony-stimulating factor (CSF) that was immunologically and molecularly related to GM-CSF. Growth of AML-CFU could be blocked by the addition of a neutralizing antiserum to GM-CSF. Northern blot hybridization of leukemic cell mRNA with a cDNA probe for the GM-CSF gene revealed a 1-kb message identical in size to the normal GM-CSF message in stimulated T cells. No GM-CSF message was detected in the third case. These results indicate that constitutive expression of the GM-CSF gene, apparently by leukemic cells, can result in autonomous in vitro proliferation of AML-CFU in some cases of AML.
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PMID:Autocrine secretion of GM-CSF in acute myeloblastic leukemia. 349 Feb 89

The CSF-1 gene encodes a hematopoietic colony-stimulating factor (CSF) that promotes growth, differentiation, and survival of mononuclear phagocytes. By using somatic cell hybrids and in situ hybridization, we localized this gene to human chromosome 5 at bands q31 to q35, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, the CSF-1 gene was found to be deleted in the 5q- chromosome of a patient with refractory anemia who had a del(5)(q15q33.3) and in that of a second patient with acute nonlymphocytic leukemia de novo who had a similar distal breakpoint [del(5)(q13q33.3)]. The gene was present in the deleted chromosome of a third patient, with therapy-related acute nonlymphocytic leukemia, who had a more proximal breakpoint in band q33 [del(5)(q22q33.1)]. Hybridization of the CSF-1 probe to metaphase cells of a fourth patient, with acute nonlymphocytic leukemia de novo, who had a rearrangement of chromosomes 5 and 21 [ins(21;5)(q22;q31.3q33.1)] resulted in labeling of the breakpoint junctions of both rearranged chromosomes; this suggested that CSF-1 is located at 5q33.1. Thus, a small segment of chromosome 5 contains GM-CSF (the gene encoding the granulocyte-macrophage CSF), CSF-1, and FMS, which encodes the CSF-1 receptor, in that order from the centromere; this cluster of genes may be involved in the altered hematopoiesis associated with a deletion of 5q.
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PMID:Assignment of CSF-1 to 5q33.1: evidence for clustering of genes regulating hematopoiesis and for their involvement in the deletion of the long arm of chromosome 5 in myeloid disorders. 349 6

A small subset of leukemic cells from most patients with acute myeloblastic leukemia (AML) have properties of stem cells and can be assayed by colony formation in agar or methylcellulose. Colony formation generally requires the addition of exogenous growth factors, but the exact factors required are incompletely defined. The AML colony-promoting activities of two recombinant human colony-stimulating factors (GM-CSF and G-CSF) were investigated by using blasts from 48 patients with AML. In nine cases, no colonies formed with either CSF. In seven cases colonies formed only in response to G-CSF and in 11 cases only in response to GM-CSF. In 21 cases colonies formed in response to either GM-CSF or G-CSF, and in 12 of these cases there was an additive effect between the two CSFs in determining maximum colony size. For cases responding to both GM- and G-CSF, the total number of colonies formed in response to the combination of both CSFs was almost always less than additive compared with the number of colonies formed in response to the individual CSFs. Further, the AML-CFU responding to either GM-CSF or G-CSF could not be distinguished by surface markers or by the cytochemical staining pattern of the colonies. These results suggest that there is considerable overlap between the GM-CSF- and G-CSF-responsive AML-CFU subpopulations in most cases. For five of seven cases, the combination of GM-CSF and G-CSF could replace a leukocyte feeder layer in providing maximum growth stimulation. These results indicate that GM-CSF and G-CSF are active growth factors for AML cells and are frequently additive in promoting maximum colony size.
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PMID:The effects of GM-CSF and G-CSF in promoting growth of clonogenic cells in acute myeloblastic leukemia. 349 5


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