Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The disappearance of normal hematopoiesis during acute nonlymphoblastic leukemia (ANLL) is poorly understood. Several reports indicate that conditioned medium obtained from leukemic cells might inhibit the formation of normal hematopoietic progenitors. However, these blast-conditioned medium (BCM) inhibitory activities are not well characterized. In order to evaluate whether BCM might contain an activity inhibiting the growth of normal marrow progenitors, BCM from 13 consecutive patients with ANLL were tested on normal bone marrow in methylcellulose assays. In all the cases, a significant inhibition of the growth of granulocyte-macrophage colony-forming unit (CFU-GM) progenitors was observed, whereas erythroid burst-forming unit (BFU-E) progenitors were not affected. Further characterization of the BCM inhibitory activity showed using both a biological assay and RIA, the presence of tumor necrosis factor-alpha (TNF-alpha) in 10 out of 13 BCM. Northern blot analysis performed in six patients showed a correlation between the expression of TNF-alpha mRNA by leukemic cells and the presence of TNF-alpha in BCM. Moreover, the BCM inhibitory activity could be neutralized with an anti-TNF-alpha antiserum. These data indicate that leukemic cells express and release frequently TNF-alpha, which may therefore play an important role in the inhibition of granulopoiesis during leukemia.
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PMID:Secretion of tumor necrosis factor-alpha by fresh human acute nonlymphoblastic leukemic cells: role in the disappearance of normal CFU-GM progenitors. 169 75

We have examined the in vitro effects of recombinant human (rh) interleukin-1 (IL-1) on the growth of purified megakaryoblasts obtained from patients with acute megakaryoblastic leukemia. We demonstrate that both IL-1 alpha and IL-1 beta treatment of these cells led to stimulation of DNA synthesis (as shown by increase of 3H-thymidine incorporation up to 35-fold) and also resulted in colony formation of leukemic megakaryoblasts. However, the stimulatory effect of IL-1 was dependent on endogenous production of IL-6, because addition of neutralizing monoclonal antibody (MoAb) to IL-6 abrogated the stimulatory activity of IL-1. In contrast, neutralizing MoAbs to granulocyte (G)-colony stimulating factor (CSF), granulocyte-macrophage (GM)-CSF, and macrophage (M)-CSF failed to counteract the growth-enhancing effects of IL-1. Leukemic megakaryoblasts accumulated IL-6 mRNA and released IL-6 protein into their culture supernatant when exposed to rh IL-1 but failed to disclose transcripts for G-, GM-, and M-CSF under these conditions. Analysis of IL-6 receptor (IL-6R) transcript levels demonstrated that megakaryoblasts constitutively expressed IL-6R mRNA and that these transcripts are down-regulated to undetectable levels upon exposure to IL-1 and IL-6. Increase of 3H-thymidine incorporation by megakaryoblasts could be duplicated by exogenous IL-6 that could be blocked by neutralizing MoAb to IL-6. In conclusion, our results suggest that leukemic megakaryoblasts could produce and secrete IL-6, and express IL-6R, and that the growth-enhancing effect of IL-1 on these cells is indirect, via production of IL-6 by leukemic cells.
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PMID:Interleukin-6 (IL-6) is an intermediate in IL-1-induced proliferation of leukemic human megakaryoblasts. 170 Jul 30

Numbers, proliferative potential, and differentiative capacity of bone marrow granulocyte-macrophage precursor cells were studied in 130 children with acute lymphoblastic leukaemia (ALL), including 77 children in an acute phase of the disease and 53 in remission. Bone marrow samples from 65 children without haematopoietic abnormalities were used as controls. The numbers of clonogenic precursors were found to be below normal in all phases of ALL, particularly during the acute period when the bone marrow was heavily infiltrated with leukaemic cells. It is shown that the decreases in the numbers and proliferative potential of the precursor cells during the acute phases was associated with the effects of leukaemic blast cells, but that in remission the observed reduction in the precursor cell pool was due to the cytostatic effect of therapy. The differentiative capacity of clonogenic granulocyte and macrophage precursors was not altered in children with ALL.
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PMID:Granulocytopoiesis in children with acute lymphoblastic leukaemia. 170 7

We evaluated the efficacy of in vitro clonogenic assays for acute myeloid leukemia (AML) (CFU-Leuk) and granulocyte-macrophage progenitor cells derived from normal bone marrow (BM) (CFU-GM) to predict hematopoietic engraftment, median survival time (MST) and leukemia-free survival (LFS) in LBN rats that received injections of untreated or drug-treated AML and/or normal BM cells. Injection of untreated AML cells resulted in a log-linear relationship between AML cell dose and time of death from leukemia; LBN rats given 10(6) cells died with AML (MST, 24 days; range, 19-28) after injection. A minimum of 0.5-1.0 X 10(6) untreated normal BM cells was needed to insure satisfactory hematopoietic reconstitution in at least 50% of lethally irradiated LBN rats. After ex vivo incubation with graded concentrations of 4-hydroperoxycyclophosphamide (4HC) or bleomycin (BLEO), LBN AML or normal BM cells were cultured for CFU-Leuk or CFU-GM and injected into untreated or lethally irradiated syngeneic recipients. Over a variety of drug concentrations (4HC, 3-30 micrograms/ml; BLEO, 100-10,000 mU/ml) and cell doses (10(6)-10(7)/animal) examined, the log-kill estimates derived from in vitro CFU-Leuk assays correlated with the observed MST or LFS. Recovery of greater than 1% CFU-GM from 4HC- or BLEO-treated suspensions of normal BM was associated with satisfactory engraftment in lethally irradiated LBN rats. Clonogenic assays also predicted for engraftment and LFS in animals that received mixtures of AML and normal BM cells (1:10) treated with 4HC and/or BLEO. We conclude that CFU-Leuk and CFU-GM assays are useful screening techniques to develop and evaluate strategies for ex vivo purging with chemotherapeutic agents in this preclinical model of autologous marrow transplantation for AML.
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PMID:Predictive value of colony-forming unit assays for engraftment and leukemia-free survival after transplantation of chemopurged syngeneic bone marrow in rats. 170 43

Using two complementary culture systems, suspension and clonal cultures, and with a method of graphic display (star diagram), we studied the effects of recombinant human interleukin-4 (IL-4) on leukemic stem cell renewal and differentiation in acute myelogenous leukemia (AML). The interactions between IL-4 and other recombinant human cytokines, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage CSF (M-CSF) and interleukins-1 alpha, -2, -3, -5, and -6 were also studied. IL-4 alone had significant effects on both self-renewal and differentiation of blast progenitors in some cases; in clonogenic assay, IL-4 stimulated blast colony formation and in one case IL-4 was the most powerful stimulator among the nine growth factors tested. Star diagrams, constructed using the data from both suspension and clonal cultures, showed that IL-4 could influence the balance between self-renewal and differentiation of clonogenic cells. Negative and positive interactions were detected between IL-4 and other cytokines in suspension culture. These results indicate that IL-4 is a cytokine with a potential role in regulating the growth of myeloid leukemic stem cells, and that IL-4 may be useful in treating selected AML patients.
Leukemia 1991 Feb
PMID:Interleukin-4 as a growth regulator of clonogenic cells in acute myelogenous leukemia in suspension culture. 170 33

Patients in first remission of acute lymphoblastic leukaemia (ALL) considered to be at high risk of relapse were offered autologous bone marrow transplantation (ABMT) using purged marrow as a therapeutic alternative to cranial irradiation and maintenance chemotherapy. Twenty-seven bone marrows taken in remission, were purged using monoclonal antibodies (anti CD7 for T lineage and anti CD10 and/or anti CD19 for B lineage leukaemias) plus rabbit complement. Retrospective analysis of 19 purged marrows by immunophenotyping or immunoglobulin gene rearrangement studies demonstrated no evidence of disease. Engraftment was seen in 26 of the patients. No correlation was found between the numbers of infused nucleated cells or colony forming units-granulocyte-macrophage (CFU-GM) and subsequent engraftment kinetics. The actuarial disease-free survival (DFS) is 32% at 7 years (median follow-up 3.4 years). There were two transplant related deaths (actuarial risk 8%); the main cause of treatment failure has been disease recurrence with an overall actuarial risk of 67%; 76% for T-ALL (five of nine), 62% for common ALL (five of 10), two of five pre B and none of three patients with B-ALL. In these 27 high risk patients in vitro purging of remission marrow as part of ABMT appears not to improve patient outcome, although confirmation of this would require a randomized trial.
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PMID:Failure of purged autologous bone marrow transplantation in high risk acute lymphoblastic leukaemia in first complete remission. 171 92

We used an in vitro clonogenic assay in semi-solid medium to test the sensitivity of normal bone marrow and acute myeloid and lymphoid leukaemia progenitors to the flavonol quercetin. We have studied 14 acute myeloid (AML) and four acute lymphoid (ALL) leukaemias. All ALL and the vast majority of AML (12/14) had a high sensitivity to quercetin with more than 50% growth inhibition at 2 x 10(-6) M quercetin. One M3-AML was partially quercetin-sensitive displaying 60% surviving AML-colony forming units (CFU-AML) at a quercetin concentration of 10(-5) M. One M1-AML was resistant to the growth inhibitory effect of quercetin at a concentration of 2 x 10(-5) M. The clonogenic efficiency of both AML and ALL positively correlated with leukaemic colony-forming unit (CFU-L) sensitivity to quercetin suggesting that this parameter can be useful in predicting quercetin responsiveness of leukaemic cells. We have also studied the effect of various quercetin concentrations on colony formation by normal bone marrow cells. At a quercetin concentration of 10(-5) M, we observed (in five different experiments) a mean recovery of 53% and 65% of erythroid blast-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), respectively. Thus, normal bone marrow appeared partially resistant to quercetin, being inhibited less than 50% by quercetin concentration higher than 2 x 10(-5). When normal bone marrow were deprived in CD34+ haematopoietic progenitors the resultant population became highly sensitive to quercetin, with a mean recovery of BFU-E and CFU-GM of 5% and 12% of controls respectively in the presence of 2 x 10(-5) M quercetin. Furthermore, CD34 progenitors, positively selected, appeared fully resistant to quercetin concentrations as high as 2 x 10(-5) M. Thus, CD34+ progenitors are a quercetin-resistant component in normal bone marrow. In conclusion, our results further provide a biological basis for the therapeutic use of quercetin, considering that this compound could inhibit leukaemic cell growth without suppressing normal haematopoiesis.
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PMID:Antiproliferative activity of quercetin on normal bone marrow and leukaemic progenitors. 177 77

The in vitro culture growth of marrow granulocyte-macrophage progenitors (CFU-GM assay) was studied in 102 consecutive patients with newly diagnosed primary myelodysplastic syndrome (MDS) to determine its diagnostic utility and prognostic value. There were 18 patients with refractory anemia (RA), eight RA with ringed-sideroblast (RARS), 30 RA with excess of blasts (RAEB), 18 chronic myelomonocytic leukemia (CMML), and 28 RAEB in transformation (RAEB-T). Patients with MDS had a significantly lower number of GM colonies and a significantly higher cluster to colony ratio than those of normal controls and patients with cytopenias of other causes. Six in vitro growth patterns were observed; 85% of patients with MDS showed various abnormal growth patterns, and 42% of all MDS patients exhibited a leukemic growth pattern at diagnosis. None of the 40 patients with cytopenias of other causes had a leukemic type growth. A leukemic growth pattern was rarely observed in patients with RA and RARS (4%), but was common in other subgroups (57%). The distribution of various growth patterns was not statistically different among patients with RAEB, CMML, and RAEB-T. Thirty-six patients developed acute leukemia during the follow-up period. The MDS patients with leukemic type growth were at increased risk of rapid progression to acute leukemia, and they also had a shorter survival time than patients with a non-leukemic pattern. These results showed that simply scoring the number of CFU-GM is of limited value for the diagnosis and the prediction of prognosis of MDS, whereas the in vitro marrow culture growth pattern is of prognostic significance independently of the FAB classification. It is concluded that the in vitro growth pattern of marrow CFU-GM is helpful in diagnosing patients with MDS as well as in predicting their clinical outcome.
Leukemia 1991 Dec
PMID:Diagnostic and prognostic values of in vitro culture growth patterns of marrow granulocyte-macrophage progenitors in patients with myelodysplastic syndrome. 177 58

To determine the role of the BCR-ABL gene in the proliferation of blast cells of patients with chronic myelogenous leukemia, leukemia blast cells were exposed to synthetic 18-mer oligodeoxynucleotides complementary to two identified BCR-ABL junctions. Leukemia colony formation was suppressed, whereas granulocyte-macrophage colony formation from normal marrow progenitors was unaffected. When equal proportions of normal marrow progenitors and blast cells were mixed, exposed to the oligodeoxynucleotides, and assayed for residual colony formation, the majority of residual cells were normal. These findings demonstrate the requirement for a functional BCR-ABL gene in maintaining the leukemic phenotype and the feasibility of gene-targeted selective killing of neoplastic cells.
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PMID:Selective inhibition of leukemia cell proliferation by BCR-ABL antisense oligodeoxynucleotides. 185 87

We show here that analysis of VpreB gene transcription can be a specific way to identify acute leukemias of cells at very early stages of B-cell development. Northern blot analysis of RNAs from 63 leukemia samples showed that VpreB RNA was present in malignancies of precursor B cells, the expression being a feature of both common acute lymphoblastic leukemia (ALL) (CD10+) and null ALL (CD10-). It was absent from malignancies of mature B cells (surface Ig positive), from acute leukemias of the T-cell lineage and granulocyte-macrophage lineages, and from normal tonsil B and T lymphocytes. Chronic myeloid leukemia blast crises of the B-precursor-cell type expressed the VpreB gene while myeloid blast crises did not. VpreB RNA was also expressed in the neoplastic cells of one of three patients with acute undifferentiated leukemias. These data show that VpreB RNA expression is a marker of the malignant forms of precursor B cells, and that it appears at least as early as cytoplasmic CD22 and CD19 in tumors of the B-cell lineage.
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PMID:VpreB gene expression in hematopoietic malignancies: a lineage- and stage-restricted marker for B-cell precursor leukemias. 188 24


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