Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor (TNF)-alpha and TNF-beta have multiple effects on human acute myeloid leukemia (AML) cells in vitro, including (1) synergistic stimulation of proliferation with interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) and upregulation of interleukin-3 (IL-3) and GM-CSF receptors; (2) inhibition of granulocyte-CSF (G-CSF)-induced growth and rapid downmodulation of G-CSF receptors; and (3) induction of autocrine growth. Recently, two distinct TNF receptors (TNF-Rs), TNF-R(p55) and TNF-R(p75), have been identified. In this study, we show that both receptor types may be expressed by AML blasts. It has been investigated whether the different effects of TNF on AML blasts can be explained by differential activation of the distinct TNF-R structures. For this purpose, we used the monoclonal antibodies HTR-1 and HTR-9, specifically recognizing TNF-R(p55), and UTR-1, specific for TNF-R(p75). TNF-(alpha and -beta) mediated synergistic activation with IL-3/GM-CSF, upregulation of IL-3/GM-CSF receptors, inhibition of G-CSF-induced growth, and rapid downmodulation of G-CSF receptors exclusively result from activation of TNF-R(p55). In certain cases in which TNF-alpha, rather than TNF-beta, induces AML growth through an autocrine mechanism, both TNF-R(p55) and (p75) are involved. These data indicate that the variety of TNF responses observed in AML can only be partially explained by differential activation of the TNF-R(p55) and (p75) structures, and that TNF-R(p55) on AML blasts can transduce both positive (synergism with IL-3/GM-CSF) and negative regulatory signals (inhibition of G-CSF-induced proliferation) following TNF activation.
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PMID:Involvement of tumor necrosis factor (TNF) receptors p55 and p75 in TNF responses of acute myeloid leukemia blasts in vitro. 138 4

The lymphokine interleukin-3 (IL-3) promotes the growth and survival of immature hematopoietic cells. Previous studies have shown that IL-3 induces rapid increases in protein-tyrosine kinase (PTK) activity in IL-3--dependent cells. Unlike some other hematopoietic growth factor receptors (eg, c-fms and c-kit), however, the known subunits of the IL-3 receptor (IL-3R) lack intrinsic kinase activity. Recently, it was reported that the IL-2R (whose p75 beta-subunit shares sequence homology with a known murine IL-3R subunit and a common beta-subunit of the human IL-3R and granulocyte-macrophage colony-stimulating factor [GM-CSF] receptors) can physically associate with and regulate the activity of the SRC-family PTK, p56-LCK. Because most IL-3--dependent cells contain p53/56-LYN, but not p56-LCK, we explored the effects of IL-3 on the activities of LYN and other SRC-like PTKs in two human leukemic cell lines, AML-193 and TALL-101, which are phenotypically myeloid, and whose in vitro growth is dependent on IL-3. These cells expressed four of the eight known SRC-family proto-oncogenes: lyn, fyn, yes, and hck. When these factor-dependent leukemic cell lines were deprived of lymphokine to achieve cellular quiescence and then restimulated with IL-3, rapid increases (detectable within 1 minute and maximal by 10 minutes) were observed in the activity of the p53/56-LYN kinase, as assessed by in vitro kinase assays. In contrast, no alteration in the activities of other SRC-family PTKs present in these cells was detected after restimulation with IL-3 under the same conditions. This effect of IL-3 reflected an increase in the specific activity of the LYN kinase, because levels of the 53-Kd and 56-Kd LYN proteins were unaltered by IL-3 stimulation, as assessed by immunoblotting. Furthermore, the magnitude of these inducible increases in LYN kinase activity was dependent on the concentration of IL-3, and correlated with IL-3--induced proliferation. The IL-3--induced upregulation of LYN kinase activity may be mediated by the 120-Kd common subunit of the human IL-3 and GM-CSF receptors, because GM-CSF also stimulated marked increases in the activity of the LYN kinase, whereas granulocyte-CSF (G-CSF) did not, despite inducing cellular proliferation. These observations provide the first example of an IL-3--regulable PTK, and strongly suggest that the p53/56-LYN kinase participates in early IL-3--initiated signalling events, at least in some human leukemic cell lines.
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PMID:Interleukin-3 regulates the activity of the LYN protein-tyrosine kinase in myeloid-committed leukemic cell lines. 163 19

Recent studies have shown that IL-2R are composed of at least two polypeptide chains of 55 kDa (Tac or alpha-chain) and 70 to 75 kDa (p70 or beta-chain). The association of both chains forms high affinity IL-2R, whereas each chain alone binds IL-2 with a low (alpha-chain) or intermediate (beta-chain) affinity. So far, the p70 peptide has been found, in the absence of the Tac peptide, on the surface of lymphoid cells of T, B, or NK lineage. In this study, we investigated whether leukemic cells of various hemopoietic lineages expressed the p70 IL-2-binding protein. We found that both fresh leukemic cells obtained from patients, and cells from established leukemic lines of T cells, B cell, and myeloid origin constitutively expressed a p70 IL-2-binding protein on their surface, as detected by affinity cross-linking of radioiodinated IL-2. IL-2 binding and cross-linking to these cells was completely inhibited in the presence of an excess unlabeled rIL-2, but not with an anti-Tac mAb. Binding experiments on pre-B and myeloid cell lines revealed intermediate affinity IL-2R, whereas both high and intermediate affinity IL-2R were detected in T leukemic cells. The intermediate affinity binding of 125I-rIL-2 to the leukemic cell lines MOLT4 and Reh6 was inhibited by the TU27 mAb, which recognized the p75 chain of IL-2R. Moreover, the TU27 mAb could stain the K562, KM3, and MOLT4 (weakly) cell lines by indirect immunofluorescence. A high dose of rIL-2 (400 U/ml) enhanced the proliferation of cells from one out of three patients with acute myeloblastic leukemia, but it did not induce differentiation of the cells in any of three cases. Thus the finding of p70 IL-2-binding molecules on immature lymphoid and nonlymphoid hemopoietic cells should disclose new biologic functions for IL-2.
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PMID:Presence of a p70 IL-2-binding peptide on leukemic cells from various hemopoietic lineages. 278 58

Serum levels of TNF, IL-6 and soluble TNF receptors p55 and p75 (sTNFR-p55 and sTNFR-p75) were examined in 14 patients with acute myeloid leukaemia during 43 courses of chemotherapy. The patients experienced 30 episodes of fever which occurred during granulocytopenia (defined as granulocyte counts < 0.2 x 10(9)/l) and six fever episodes when granulocyte counts were > 1.0 x 10(9)/l. Febrile episodes were classified as microbiologically defined infection, clinically defined infection, and unexplained fever. Levels of bioactive IL-6 and immunoreactive TNF increased in response to fever during granulocytopenia, whereas bioactive TNF was not detected in any sample in this study. During granulocytopenia, both sTNFR rose significantly in microbiologically defined infection (P < 0.01 for sTNFR-p55 and P < 0.05 for sTNFR-p75), but not in the other two categories. The ratio of sTNFR-p55 to sTNFR-p75 was higher during febrile periods in granulocytopenia than in a non-granulocytopenic situation with granulocyte counts > 1.0 x 10(9)/l (P < 0.01). We conclude that granulocytopenia affects release of the two sTNFR differently during febrile periods, and that release of sTNFR-p75 in response to fever is reduced during granulocytopenia, suggesting a role for the granulocytes in systemic release of sTNFR-p75.
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PMID:Soluble tumour necrosis factor receptors, tumour necrosis factor and interleukin-6 in serum in granulocytopenic patients with fever. 777 8

In the present study, we have investigated the leukemic cells obtained from 16 patients with acute myeloid leukemia (AML) at diagnosis for the membrane expression of p55 (alpha) and p75 (beta) interleukin-2 receptor (IL-2R) chains using specific monoclonal antibodies (mAbs), as well as for the presence of their transcripts using Northern blot analysis. In addition, immunoprecipitation of the p75 membrane molecule with TU27 and Mik-beta 1 mAbs was carried out in selected cases. The p75 IL-2R beta transcripts were detected in all cases, whereas the membrane p75 molecule was demonstrable by flow cytometry in three cases. However, data from the immunoprecipitation analysis suggest that the lack of the p75 IL-2R detection by flow cytometry might be caused by the low density of molecules per cell rather than the fact that the specific mRNA is not translated into the p75 surface molecule. In addition, a consistent membrane positivity with an anti-p55/CD25 mAb, present on fresh uncultured blasts in 37.5% of the cases, became detectable after short-term culture in 75% of cases. In each individual case, a strict correlation was found between membrane CD25 reactivity and the expression of p55 mRNA. Taken together, our data suggest that the expression of both alpha (p55) and beta (p75) IL-2R molecules is a common feature of leukemic cells in AML, and provide new arguments for reassessing the possible role of IL-2 in leukemic growth.
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PMID:Alpha (p55) and beta (p75) chains of the interleukin-2 receptor are expressed by AML blasts. 844 47

Expression of the interleukin-2 receptor alpha-(IL-2Ralpha-), IL-2Rbeta-, and the recently identified IL-2Rgamma-chain was examined on a wide range of cells of myeloid origin including neutrophils, monocytes, normal bone marrow-derived myeloid progenitors enriched for CD34+ cells, bone marrow blasts obtained from acute myelogenous leukemia (AML) patients, and permanent myeloid leukemia cell lines by reverse transcriptase-polymerase chain reaction and surface membrane analysis using receptor chain-specific monoclonal antibodies and flow cytometry. Expression of the p75 IL-2Rbeta- and the p64 IL-2Rgamma-chain was a common finding in most of the myeloid cell samples investigated, whereas IL-2Ralpha-chain was less frequently expressed. Although the high-affinity IL-2R form (ie, the alpha+, beta+, gamma+ IL-2R form) was detectable in a small minority of primary AML samples as well as the KG-1 cell line and IL-2 binding to these cells was sufficient to initiate signal transduction as evidenced by an increase in overall protein tyrosine phosphorylation and more specifically in tyrosine phosphorylation of the Janus kinase (JAK) 3, in none of these cell types did exposure to IL-2 affect cell growth kinetics. These results suggest that, in myeloid cells, the IL-2R may not stimulate mitogenic responses or that its components may be expressed in a combinational association with receptors for other cytokines and that IL-2Rgamma may play a regulatory role in normal and malignant myelopoiesis possibly independent from IL-2. Because recent studies by others have indicated that the IL-2Rgamma- chain may be shared by the IL-4R, the IL-7R, and most likely the IL-9R, expression of mRNA of these receptor types was also investigated in these cell samples. Surprisingly, in a substantial part of the myeloid lineage cells examined, an IL-2Rgamma+, IL-4R-, IL7R- configuration was noted that was, however, frequently associated with expression of IL-9R. Sharing of IL-9R/IL-2R components was furthermore suggested by inhibition of 125I-IL-2 binding to primary AML cells with excess of unlabeled IL-9.
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PMID:Transcript synthesis and surface expression of the interleukin-2 receptor (alpha-, beta-, and gamma-chain) by normal and malignant myeloid cells. 863 Apr 6

Matrix metalloproteinases have been reported to be involved in tumor cell invasion and metastasis. Dissemination of malignant cells in acute myeloid leukemia (AML) may be mediated by similar mechanisms. Here, we report, that the t(15/17)+ acute promyelocytic leukemia (APL) cell line NB4 constitutively expresses and releases the proenzyme form of matrix metalloproteinase-9 (MMP-9, 92 kDa type IV collagenase/gelatinase, gelatinase B), as well as tissue inhibitor of metalloproteinases-1 (TIMP-1). Both proteins were identified by N-terminal amino acid sequence analysis after purification using gelatin Sepharose affinity chromatography. Whereas 12-O-tetradecanoylphorbol-13 acetate (TPA) increased both MMP-9 and TIMP-1 mRNA levels, tumor necrosis factor-alpha (TNF-alpha) stimulated only MMP-9 gene expression in a dose- and time-dependent manner. Neutralizing monoclonal antibodies (MoABs) to TNF-alpha (anti-TNF-alpha) decreased the constitutive and TPA-dependent expression of MMP-9 but did not influence TIMP-1 expression, either in unstimulated or in TPA-treated NB4 cells. FACS analyses showed that NB4 cells express both TNF receptor 1 (TNF-R1) and TNF-R2 to a similar extent. Blocking MoABs against TNF-R 1 (anti-TNF-R1) decreased the constitutive expression of MMP-9, whereas anti-TNF-R2 had almost no effect. Our results show, that in NB4 cells the expression of MMP-9 but not of TIMP-1 is maintained by autocrine stimulation with TNF-alpha. Thus, leukemic cells may be enabled to leave the bone marrow and infiltrate peripheral tissues by a dysfunction in the regulation of the MMP-9:TIMP-1 equilibrium, possibly triggered through autostimulation by TNF-alpha.
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PMID:Autocrine regulation of matrix metalloproteinase-9 gene expression and secretion by tumor necrosis factor-alpha (TNF-alpha) in NB4 leukemic cells: specific involvement of TNF receptor type 1. 966 1

The tumour necrosis factor (TNF)/TNF-receptor (TNFR) complex plays a role in the growth of leukaemic cells. We retrospectively investigated the relationship between pretreatment serum concentration of soluble TNFR (p55- and p75-sTNFRs) and outcome in adult acute myeloid (AML 82 cases) and lymphoid (ALL 44 cases) leukaemia. Both sTNFRs were significantly higher in AML (p55-sTNFR 4.53 +/- 3.7, median 3.75; p75-sTNFR 6.51 +/- 5.25 ng/ml, median 4.72) and ALL sera (3.31 +/- 1.5, median 2.95; 5.30 +/- 2.3 ng/ml, median 4.56, respectively) than in controls (1.89 +/- 0.5, median 1.98; 2.22 +/- 0.8 ng/ml, median 2.37) (P < 0.01 for both sTNFRs). Fresh leukaemic cells expressed p55- and p75-sTNFRs, which were modulated and released into the supernatant (SN) following short-term in vitro culture, suggesting that in vivo sTNFRs were also leukaemia-derived. Whereas no correlation was observed between sTNFRs and outcome in ALL, in AML higher p55-sTNFR levels (> 3.75 ng/ml) were associated with shorter disease-free survival (DFS) (P = 0.006) and overall survival (OS) (P = 0.0004). At multivariate analysis p55-sTNFR was the most significant predictor of DFS (P = 0.006) and OS (P < 0.001). Our data suggest that the prognostic significance of p55-sTNFR in AML could be related to relevant biological features of AML blasts.
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PMID:Serum levels of p55 and p75 soluble TNF receptors in adult acute leukaemia at diagnosis: correlation with clinical and biological features and outcome. 973 54

Cytokines such as interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) activate monocytes both in vitro and in vivo. We therefore studied whether the anti-leukaemic activity of monocytes could be augmented by IL-3 alone or in combination with GM-CSF. Using normal human monocytes stimulated with IL-3, GM-CSF, LPS or combinations of growth factor and LPS, we studied their cytotoxic activity against leukaemic cell-lines and primary AML blasts. IL-3 like GM-CSF, augmented the expression and secretion of TNF but did not prime for further expression and secretion of TNF in response to LPS. Neither GM-CSF or IL-3 increased the expression or secretion of TNF receptor p55 (TNF-Rp55), although both agents increased expression of TNF receptor p75 (TNF-Rp75). Monocyte-mediated cytotoxicity (MMC) against K562 and U937 cell-lines was increased by both GM-CSF and IL-3 stimulation, and both cytokines primed monocytes for increased killing of K562 and KG-1 cell-lines as well as primary AML blasts in response to LPS. The mechanism of action of MMC was largely confirmed to be via surface-bound TNF, although other TNF-independent mechanisms must have been involved.
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PMID:Cytokine modulated cell-membrane bound tumour necrosis factor expression is associated with enhanced monocyte-mediated killing of human leukaemic targets. 1071 29

A t(9;11)(p22;p15) chromosomal translocation was identified in an adult patient with de novo acute myelogenous leukemia. Fluorescence in situ hybridization and Southern blot analysis mapped the 11p15 break-point to the NUP98 gene. Using 3' rapid amplification of cDNA ends, we have identified a chimeric mRNA that fused the NUP98 FXFG repeats in frame to the COOH-terminal portion of the gene encoding the transcriptional coactivators p52 and p75, also known as lens epithelium-derived growth factor (LEDGF). As expected, both NUP98-p52 and NUP98-p75 (LEDGF) chimeric mRNAs were detected by reverse transcription-PCR; however, the reciprocal p52/p75 (LEDGF)-NUP98 fusion mRNA was not detected. Our results demonstrate that this is the most 5' NUP98 fusion reported and reveal a previously unrecognized genetic target, the gene encoding p52/p75 (LEDGF).
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PMID:t(9;11)(p22;p15) in acute myeloid leukemia results in a fusion between NUP98 and the gene encoding transcriptional coactivators p52 and p75-lens epithelium-derived growth factor (LEDGF). 1110 74


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