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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of the tumor necrosis factor (TNF), and a second pleiotropic cytokine interferon-gamma (IFN), were examined in a line of human myeloblastic leukemia cells (ML-1). By itself, TNF causes ML-1 to differentiate along the monocytic pathway. The cells exhibit an increase in Fc receptors and acquire the morphological characteristics of maturing phenotype. They remain viable and continue to proliferate (at greater than or equal to 50% of the control growth rate) even with 10(2)-10(4) units/ml TNF. IFN alone has similar effects, causing an increase in Fc receptors but little cytotoxicity. In contrast to either cytokine alone, the combination of TNF plus IFN causes a cessation of proliferation and extensive cell death. Cytotoxicity occurs in a synergistic fashion; it requires the simultaneous presence of both cytokines, occurring with concurrent but not sequential exposure. These different responses, differentiation (TNF alone) and cytotoxicity (TNF + IFN), occur with a similar range of doses (approximately 10(2)-10(4) units/ml) and in a similar time frame (beginning on day 2). In other cell types, IFN can augment either the differentiation-inducing or the cytotoxic effect of TNF. In ML-1, the combined application of TNF plus IFN results in a shift from differentiation to cytotoxicity.
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PMID:Differentiation-inducing and cytotoxic effects of tumor necrosis factor and interferon-gamma in myeloblastic ML-1 cells. 250 96

Production of interleukin 1 (IL-1) by leukemic cells was studied in 13 cases of acute myeloid leukemia. Intracytoplasmic immunofluorescence studies showed that the cells invariably contained the cytokine. Endogenous labeling studies demonstrated that acute myeloid leukemia cells produced either only the 33-kDa propeptide or both the propeptide and the 17-kDa mature form of IL-1 beta. The 33-kDa propeptide IL-1 alpha was always produced but was less frequently released. Involvement of IL-1 in leukemic cell growth was investigated using two antibodies specific for IL-1 subtypes, which inhibited spontaneous cell proliferation in the six cases studied. After acid treatment of the cells, a surface receptor for IL-1 could be demonstrated, which mediated 125I-labeled IL-1-specific uptake by leukemic cells. Furthermore, recombinant IL-1 alpha or IL-1 beta induced significant cell proliferation in 10 of 12 cases. The above findings were uncorrelated with the cytologic type (French-American-British classification) of leukemia. Our studies suggest that IL-1 may act as an autocrine growth factor in most cases of acute myeloid leukemia.
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PMID:Interleukin 1 as an autocrine growth factor for acute myeloid leukemia cells. 252 58

The effect of alpha interferon (alpha IFN) on colony forming unit, granulocyte-macrophage (CFU-GM) formation by normal bone marrow (BM) as compared with chronic granulocytic leukaemia (CGL) BM and peripheral blood (PB) was tested in semi-solid assay systems employing either 5637CM or recombinant granulocyte-macrophage colony stimulating factor (GM-CSF) to support growth. alpha IFN (greater than 125 U/ml) caused consistent inhibition (P = 0.02) of day-7 (late progenitor) colonies, but had little or no effect on either day-7 clusters or day-14 colonies/clusters. This selective effect on day-7 colonies was quantitatively similar for both normal and CGL (P greater than 0.5). Similar results were obtained whether or not the mononuclear preparations were depleted of potential accessory cells, suggesting that the alpha IFN-suppression is directly mediated. Morphological examination of colonies and clusters showed that IFN had no effect on cell maturation and that colony inhibition is not, therefore, a consequence of blocked maturation. Since the late-progenitor compartment is preferentially expanded in CGL, we suggest that our demonstration that alpha IFN selectively inhibits this compartment is relevant to the clinical effects of the cytokine in the disease.
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PMID:Mechanism of action of alpha interferon in chronic granulocytic leukaemia: evidence for preferential inhibition of late progenitors. 261 Nov 35

Tumor necrosis factor (TNF) is a Mr 17,000 cytokine produced by macrophages. We have recently demonstrated that TNF is also produced by transformed human epithelial cells. The present studies have examined TNF expression in human myeloid leukemic cells. We have monitored TNF expression at a cellular level using alkaline phosphatase detection of a biotinylated TNF cDNA probe in situ. Using this approach, TNF transcripts were detectable in HL-60 cells induced along the monocytic lineage by phorbol ester but not in uninduced cells. The specific detection of TNF RNA at a cellular level was supported by the absence of histochemical staining in RNase-treated cells and when using biotinylated pBR322 plasmid without insert. These studies were extended to preparations of purified acute myeloblastic leukemia cells. The results demonstrate that TNF is expressed in myeloblasts in eight of nine patients with AML. In each preparation of myeloblasts with detectable TNF RNA, transcripts were present at 89-98% of the cells. The identification of TNF RNA in situ was also associated with the detection of TNF protein in leukemic blasts by indirect immunofluorescence. Moreover, the detection of TNF protein in these preparations of myeloblasts was confirmed by immunoblotting. However, using this approach to examine AML cells before and after purification indicated that TNF expression is induced as a result of the enrichment procedures. Thus, certain populations of purified myeloid leukemic cells are capable of expressing TNF at both the RNA and protein levels.
Leukemia 1989 Jan
PMID:Detection of tumor necrosis factor gene expression at a cellular level in human acute myeloid leukemias. 264 77

Leukemic cell growth in the marrow microenvironment may be modulated by stromal cell products, including stimulatory growth factors and the inhibitory regulator prostaglandin E. The production of both of these stromal cell products induced by cytokine mediators appears to be closely linked. Cyclic AMP (cAMP) is an intracellular second messenger that inhibits myeloid cell proliferation and is produced in myeloid leukemia cells on stimulation of adenylate cyclase enzyme by prostaglandin E1 (PGE1). Cells expressing the product of an RAS oncogene have been observed to display diminished hormone-stimulated adenylate cyclase of membranes. If this observation were applicable to myeloid cells, a potentially important mode for leukemia cells expressing p21 RAS to escape inhibitory regulation within the hematopoietic microenvironment would be identified. We studied an interleukin-3 (IL-3)-dependent myeloid cell line, NFS/N1.H7, and a derivative line transfected with H-RAS codon 12 (T24) oncogene, H7 Neo Ras.F3, for inhibition of proliferation by PGE1, 1 microM, alone or in combination with pertussis toxin, which inactivates Gi, an inhibitory regulatory guanosine triphosphate (GTP)-binding protein of adenylate cyclase. NFS/N1.H7 cells were inhibited in interleukin-3-dependent proliferation (dose range, IL-3 10 to 100 U/mL) by PGE1 79 +/- 11%, by pertussis toxin 51 +/- 9%, and by the combination 92 +/- 2%, whereas H7 Neo RAS.F3 was inhibited 51 +/- 7%, 6 +/- 2%, or 58 +/- 9% by PGE1, pertussis toxin, and the combination, respectively. These differences in capacity for inhibition by adenylate cyclase agonists between RAS-transfectant cells (lower inhibition) versus parent cells (greater inhibition) were all highly significant (P less than .0005). Intracellular cAMP formed on PGE1 stimulation of pertussis-intoxicated cells was 150% lower in RAS-transfectant cells than in parent cells. The adenylate cyclase activity of membranes from pertussis-intoxicated RAS-transfected cells was 1.5 to two times lower than that of pertussis-intoxicated parent-cell membranes on Mg2+-dependent activation by hormone and/or guanine nucleotide. However, very similar adenylate cyclase activity was observed in oncogenic p21 RAS-containing membranes compared with parental membranes under conditions of direct activation by 4 mM Mn2+ and forskolin, where inhibitory or stimulatory G-protein influences are minimal. These studies showed diminished adenylate cyclase activity in mutant RAS-bearing myeloid-cell membranes compared with parent-cell membranes independent of the pertussis toxin-sensitive G protein, Gi.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effector function for RAS oncogene in interleukin-3-dependent myeloid cells involves diminished efficacy of prostaglandin E1-mediated inhibition of proliferation. 267 12

The present investigation demonstrates that leukoregulin, a cytokine secreted by natural killer (NK) lymphocytes up-regulates the sensitivity of tumor cells to lymphokine-activated killer (LAK) cell cytotoxicity. It has been previously established that leukoregulin increases the sensitivity of sarcoma, carcinoma and leukemia cells to natural killer (NK) cell cytotoxicity. Tumor cells were treated with leukoregulin for 1 h at 37 degrees C and tested for sensitivity to NK and LAK cytotoxicity in a 4-h chromium-release assay. NK-resistant Daudi, QGU and C4-1 human cervical carcinoma cells became sensitive to NK cytotoxicity after leukoregulin treatment, and their sensitivity to LAK was increased two- to sixfold. Y-79 retinoblastoma cells, which are moderately sensitive to NK and very sensitive to LAK, became increasingly sensitive (two- to four-fold) to both NK and LAK cell cytotoxicity. Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF), recombinant interleukin-1 (alpha and beta), recombinant interferon gamma, recombinant tumor necrosis factor or combinations of the latter two failed to up-regulate tumor cell sensitivity to NK and LAK cell cytotoxicity. However, treatment with recombinant interferon gamma for 16-18 h, GM-CSF and interleukin-1 beta for 1 h induced a state of target cell resistance to both NK and LAK cell cytotoxicity. Leukoregulin may have an important physiological function in modulating NK and LAK cell cytotoxicity by increasing the sensitivity of target cells to these natural cellular immunocytotoxicity mechanisms.
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PMID:Leukoregulin up-regulation of tumor cell sensitivity to natural killer and lymphokine-activated killer cell cytotoxicity. 268 71

Abnormalities of the production of interleukin-2 (IL-2) may play an important role in the immunologic dysfunction observed in pediatric leukemia patients. For an evaluation of the ability of lymphocytes from leukemic children to produce this cytokine, the production of IL-2 by mitogen-stimulated peripheral blood mononuclear cells was determined in children with acute leukemia at the time of diagnosis, during clinical remission, and at the time of relapse. Of 16 patients, 11 (69%) with either acute lymphoblastic leukemia or acute nonlymphoblastic leukemia at the time of diagnosis had IL-2 production levels above the highest level observed in control subjects, and all but one had values above the control mean. Three of five treated patients had elevated IL-2 production at the time of bone marrow relapse. In addition, of 37 patients examined during clinical remission (both during chemotherapy and after the completion of maintenance chemotherapy), five had IL-2 production values above the control range and four of these five patients subsequently had relapses, compared with only one relapse in the remaining 32 patients with normal or below-normal levels of IL-2 production. These results demonstrate an increased ability to produce IL-2 by many patients with acute leukemia, both at the time of diagnosis and at relapse. Elevated IL-2 production may represent an immunologic response to leukemic cells and in some patients may provide a marker for persistent leukemia.
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PMID:Elevated production of interleukin-2 by lymphocytes from children with acute leukemia. 278 65

The cytokine secreted by a human hybrid B cell line (STS 25) obtained by fusion of the B lymphoblastoid cell line WI-L2-729-HF2 with neoplastic B cells from a patient with B cell non-Hodgkin's lymphoma (B-NHL) was characterized as IL-1 alpha. STS 25 cells express the idiotypic (Id+) immunoglobulin (Ig) specific for the neoplastic B cells of the B-NHL patient. STS 25 cells are weakly positive for surface mu delta kappa and in addition express the surface markers CD19, CD20, CD23, HLA class I and II, and the 4F2 activation antigen. STS 25 cells are also Epstein-Barr nuclear antigen positive but do not secrete viral particles. Serum-free culture supernatant from STS 25 cells (STS 25 SUP) does not show activity in assays for interleukin-2 (IL-2), -4 (IL-4), -6 (IL-6), interferon or tumor necrosis factor, but is active in the thymocyte costimulation assay and the D10.G4.1 T helper clone proliferation assay for interleukin-1 (IL-1). The IL-1 character of the STS 25 SUP activity was confirmed in inhibition studies with three different poly- or monoclonal anti-IL-1 antibodies (31, 88, and 94% inhibition in thymocyte costimulation assay, respectively). Furthermore, complete blocking of D10.G4.1 cell proliferation mediated by STS 25 SUP was observed by including anti-IL-1 alpha specific antibody in the assay, whereas anti-IL-1 beta antibody had no effect. These results indicate that this STS 25 SUP activity can be attributed to the presence of IL-1 alpha in the supernatant. Northern blot analysis of total STS 25 cellular RNA using IL-1 alpha or IL-1 beta specific probes revealed the constitutive expression of IL-1 alpha messenger RNA by STS 25 cells. In contrast, no IL-1 beta message was detectable, not even after treatment of the cells with phorbol ester or cycloheximide, which resulted in approximately 5-fold enhancement of IL-1 alpha mRNA expression. Binding studies with radiolabeled recombinant (r) IL-1 alpha indicated the presence of high numbers of IL-1 receptors on STS 25 cells (1,170 per cell, Kd = 392 pM). Although both IL-1 alpha and IL-1 beta bound to these IL-1 receptors, no indication was found for IL-1 mediated regulation of STS 25 cell growth.(ABSTRACT TRUNCATED AT 400 WORDS)
Leukemia 1989 Aug
PMID:Functional and molecular characterization of B cell line derived interleukin-1 alpha. 278 53

Autonomous in vitro growth of myeloid leukemic colony-forming cells may in part result from autocrine production of colony-stimulating factors (CSF). Some acute myeloid leukemia (AML) samples, however, fail to synthesize CSF despite growing autonomously in agar, and are therefore believed to bypass CSF requirements. Cytokines such as IL-6, tumor necrosis factor (TNF)-alpha, and IL-1, products of cells of the myeloid lineage, are known to be involved in growth control of myeloid progenitor cells. Since these molecules may also contribute to autocrine and paracrine growth regulation of myeloid leukemias, we screened a series of AML for cytokine production. In addition, possible roles of IL-6, TNF-alpha, and IL-1 in growth control of AML were investigated in vitro. We show that a substantial proportion of AML cells produce IL-6, TNF-alpha, and IL-1-beta and use these mediators to stimulate their growth by disparate mechanisms: IL-6 acts as a costimulator to enhance CSF-induced clonogenicity of AML blasts. TNF-alpha induces CSF production by endothelial cells and may therefore provide a paracrine loop to support leukemia growth.
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PMID:Participation of the cytokines interleukin 6, tumor necrosis factor-alpha, and interleukin 1-beta secreted by acute myelogenous leukemia blasts in autocrine and paracrine leukemia growth control. 1456 12

Bacterial products are potent stimulators of TNF and IL-1 release, however, the factors that regulate cytokine secretion in the absence of bacterial products are not well defined. P48 is a cytokine recently identified in the supernatant of the human null cell leukemia cell line Reh, which induces differentiation and cytolytic activity in HL-60 cells. P48 has been purified to homogeneity and is distinct from TNF-alpha TNF-beta, IFN-gamma, IL-6, and macrophage CSF. In the present study we examined the ability of P48 to stimulate cytokine release by human peripheral blood monocytes. P48 stimulated the secretion of TNF and IL-1 in a dose-dependent manner. Priming the monocytes with IFN-gamma enhanced P48-induced cytokine release but was not a requirement for secretion. Cytokine secretion was in response to P48 and was not caused by endotoxin contamination. The cytokine-inducing activity of P48 was extremely sensitive to heat treatment but could not be eliminated by using polymyxin B. Polyclonal antisera to P48 completely blocked the cytokine-inducing activity. P48 may be an important new member of the cytokine network involved in the regulation of cytokine secretion by monocytes.
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PMID:P48 induces tumor necrosis factor and IL-1 secretion by human monocytes. 280 97


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