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)

Two new murine monoclonal antibodies were prepared by hybridoma technique after immunization with the immature pluripotent leukemia cell line K562. The monoclonal antibody Bra10G (IgG2b) reacted in a non-lineage pattern with all examined hematopoietic neoplastic cell lines and peripheral blood cells (granulocytes, lymphocytes, erythrocytes) of healthy donors, with the exception of monoblastoid cell line U-937 and B lymphoma cell line Daudi. This monoclonal antibody immunoprecipitated an 18-20 kDa cell surface protein expressed also on the cell surface of examined non-hematopoietic (malignant glioma, melanoma and breast carcinoma) cell lines. These properties and the efficient inhibition of Bra10G binding to the cell surface of K562 cells by the reference CD59 monoclonal antibody (MEM-43) indicated that Bra10G belongs to the CD59 cluster of monoclonal antibodies which identify the human protectin molecule. The monoclonal antibody Bra7G (IgM) reacted with a 95 kDa cell surface protein expressed on hematopoietic cells (with the exception of erythrocytes) and was absent on the examined non-hematopoietic neoplastic cell lines. These data together with a partial inhibition of Bra7G binding by the reference CD-43 monoclonal antibody suggested the CD43 (leukosialin, sialophorin) specificity of this monoclonal antibody.
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PMID:Monoclonal antibodies to two adhesive cell surface antigens (CD43 and CD59) with different distribution on hematopoietic and non-hematopoietic tumor cell lines. 128 43

A 58-year-old male was diagnosed as having paroxysmal nocturnal hemoglobinuria (PNH) with myelofibrosis in 1984. The administration of hydroxyurea and low dose splenic irradiation were initiated for abdominal distention due to splenomegaly in 1987. In May 1990 the patient developed smouldering acute myeloblastic leukemia (AML); and the blasts proliferated in response to G-CSF administered for refractory pneumonia. The patient died of pneumonia and pleural involvement of leukemia in September 1990. FACS analysis of the blasts using anti-decay accelerating factor (DAF) (CD55) and CD59 (membrane attack complex inhibition factor: MACIF) monoclonal antibodies demonstrated that 25.5% and/or 87.3% of the blasts were negative for DAF or CD59 respectively. There is the earlier evidence that about 90% leukemic myeloblasts from non-PNH AML patients are positive for DAF, and nearly 100% of non-PNH neutrophils have been shown to be positive for both DAF and CD59. Our data suggest that the leukemic blasts from this patient may have derived from the PNH clone.
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PMID:Paroxysmal nocturnal hemoglobinuria with myelofibrosis: progression to acute myeloblastic leukemia. 751 53

Peripheral blood T lymphocytes obtained from two patients with paroxysmal nocturnal hemoglobinuria (PNH) were immortalized with human T-lymphotropic virus type 1 (HTLV-1). These cells showed interleukin-2 (IL-2)-dependent cell growth in culture. Cell surface analysis showed that they had the phenotype of a helper/inducer T subset that was positive for CD2, CD3, and CD4, but negative for CD8, similar to adult T-cell leukemia cells induced by HTLV-1. These cell lines lacked glycosylphosphatidylinositol (GPI)-anchored proteins, CDw52, CD55 (decay-accelerating factor; DAF), and CD59 on the cell surface, whereas intracellular DAF protein was detected. These T-subset cell lines with a PNH phenotype did not synthesize GPI anchor, whereas a control cell line, similarly prepared from the T cells of a healthy volunteer, produced the anchor. The control cells expressed CDw52, DAF, and CD59 on the cell surface and showed the phenotype of a helper/inducer subset. Southern blot analysis confirmed the clonality of each cell line. These CD4+ T-cell lines with a PNH phenotype and a subset-matched control counterpart could be a useful model for PNH investigation.
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PMID:Interleukin-2-dependent T-cell lines established from paroxysmal nocturnal hemoglobinuria patients. 751 13

We performed a flow cytometric analysis using monoclonal antibodies to decay accelerating factor (DAF) and CD59/membrane attack complex inhibitory factor (CD59/MACIF) in order to investigate the leukemic cells and erythrocytes from a patient with paroxysmal nocturnal hemoglobinuria (PNH) who developed acute myelocytic leukemia. In May 1990, the leukemic cells comprised 70% of the mononuclear cells in the bone marrow and 76% of those in the peripheral blood. They consisted of a mixture of positive and negative populations, including single DAF-positive cells. In August 1990, almost 100% of the peripheral mononuclear cells were leukemic blasts, and these consisted of a single population with reduced DAF expression. Single-color flow cytometric analysis showed that the leukemic cells lacked CD59/MACIF, while control leukemic cells (n = 3) expressed both DAF and CD59/MACIF. Leukemic blasts from this patient and six control patients expressed lymphocyte function-associated antigen 3 and FcIII receptors (CD 16) both before and after treatment with phosphatidylinositol-specific phospholipase C. The patient's erythrocytes lacking DAF and CD59/MACIF expression corresponded to the proportion of complement-sensitive cells at the onset of acute leukemia. These DAF- and CD59/MACIF-deficient erythrocytes disappeared almost completely with progression of the leukemia. In conclusion, it appears that the expression of glycosylphosphatidylinositol-linked membrane proteins by leukemic cells was heterogeneous and discordant in our patient, and that the leukemic cells were derived from the PNH clone because of their deficiency of CD59/MACIF. It is also suggested that DAF could compete more effectively than CD59/MACIF for a limited number of anchor molecules available on the proliferating leukemic cells.
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PMID:Discordant and heterogeneous expression of GPI-anchored membrane proteins on leukemic cells in a patient with paroxysmal nocturnal hemoglobinuria. 768 3

We have localized the human CD59 gene encoding a membrane protein that inhibits cell lysis by the membrane-attack complex of the homologous complement system. Using chromosomal in situ suppression hybridization and pulsed-field gel electrophoresis, we mapped this gene to chromosome 11p13, distal to the breakpoint of acute T-cell leukemia and proximal to the locus of the Wilms' tumor gene on a 30-kb SacII fragment.
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PMID:Localization of the human CD59 gene by fluorescence in situ hybridization and pulsed-field gel electrophoresis. 768 94

In 68 patients with different leukemias the expression of the following adhesion molecules was examined: CD11a, CD18, CD54, CD44, CD58, and CD59. While in normal individuals all these molecules are broadly expressed on leukocytes, in patients with leukemias the following deviations were observed: (a) at least one of the examined molecules was missing in 64/68 cases (94%); in 12/68 cases (18%) both molecules LFA-1 and ICAM-1 were missing, in 37/68 (54%) either LFA-1 or ICAM-1, and in 15/68 cases (22%) adhesion molecules other than LFA-1 or ICAM-1 were missing; (b) the expression of CD11a/CE18, CD58, CD59 on leukemic cells was heterogeneous, without any clear correlation to the subclass of leukemia; (c) in the majority of cases, CD54 (45/68; 66%) and CD44 (36/68; 53%) were missing, however showing a tendency of expression on leukemic cells with more mature immunophenotype.
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PMID:Lack of expression of adhesion molecules on leukemic cells: possible pathogenetic factor in blood malignancies. 793 81

We have investigated the mechanisms of defects in the glycosyl-phosphatidylinositol (GPI)-anchored complement regulatory proteins delay-accelerating factor (DAF) and/or CD59 in a panel of human leukaemia cell lines that lack surface expression of these proteins: U937 (DAF+/CD59-), CEM (DAF-/CD59+), TALL (DAF-/CD59-) and a substrain of Ramos [Ramos(-)] (DAF-/CD59-). Northern blotting and reverse transcription-PCR revealed that the main cause of the DAF and/or CD59 deficiency is the failure of mRNA expression in most of the cell lines, except in Ramos(-) in which sufficient mRNA for DAF and CD59 was produced. U937, CEM and TALL cells were not defective in GPI anchor formation as assessed by the detection of other GPI-anchored proteins. No gene abnormality corresponding to DAF or CD59 was detected by Southern blotting. Thus the cause of the defects of DAF and/or CD59 in these leukaemia cell lines except for Ramos(-) is virtually undetectable steady-state levels of the relevant mRNA, most likely attributable to lack of transcription in these cell lines. On the other hand, Ramos(-) cells failed to generate a GPI anchor, whereas they normally expressed DAF and CD59 transcripts. The transfection of phosphatidylinositol-glycan class A (PIG-A) cDNA into Ramos(-) cells restored DAF and CD59 expression, indicating that the defective mechanism in GPI anchor formation is similar to that in paroxysmal noctural haemoglobinuria (PNH) cells, i.e. a deficiency of the PIG-A gene product. Thus the mechanisms of the defects of DAF and/or CD59 in human leukaemia cell lines are not uniform, and in most cases are different from that proposed to cause PNH.
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PMID:Mechanisms by which the surface expression of the glycosyl-phosphatidylinositol-anchored complement regulatory proteins decay-accelerating factor (CD55) and CD59 is lost in human leukaemia cell lines. 861 96

The membrane expression of nine glycosyl phosphatidyl inositol (GPI)-linked molecules was analyzed by flow cytometry on circulating cells from 18 patients affected by paroxysmal nocturnal hemoglobinuria (PNH). The results allowed us to select CD66b, CD14, CD59, CD24 and CD59 monoclonal antibodies as the most suitable reagents for discriminating between normal and PNH cells in PMN, monocytes, RBC and B or T lymphocytes, respectively. In order to assess whether the analysis of distinct cell populations could provide differential information on the extent of the disease, we compared the proportion of residual normal cells in RBC, monocyte and PMN populations. The mean percentage of unaffected cells was higher in RBC as compared to PMN (50.5 +/- 18.7 vs 17.7 +/- 19.7, P < 0.0001). The proportion of normal PMN was, in turn, significantly greater than that of normal monocytes (17.7 +/- 19.7 vs 8.7 +/- 11.0; P < 0.05). The percentage of CD14+ monocytes was directly related to Hb concentration and platelet (Plt) count, and inversely to percent lysis at the Ham's test. The percentage of CD66b+ PMN was directly related to Plt count and Hb level, while the percentage of CD59+ RBC was associated, in an inverse fashion, only to the Ham's test. No significant correlation was found between cell marker expression and PMN count, reticulocytosis, bilirubin and serum LDH. By dividing the patients into two groups, according to high (> 10 percent) or low (< 10 percent) percentage of CD14+ monocytes, a statistical analysis showed that the main hematological parameters were significantly different.
Leukemia 1996 Aug
PMID:Blood cell flow cytometry in paroxysmal nocturnal hemoglobinuria: a tool for measuring the extent of the PNH clone. 870 38

Paroxysmal nocturnal haemoglobinuria (PNH) terminating in acute leukaemia (AL) is an infrequent condition. In several cases, flow cytometric analysis of glycosylphosphatidylinositol anchored membrane proteins such as DAF and CD59/MACIF has suggested the leukaemic cells to be derived from the PNH clone, thereby implicating PNH as a potential preleukaemic disease. In the present paper, we review the data for one patient treated in our hospital and 20 cases reported in the literature from 1969 to 1993. The sex ratio is 1 female/2 males, mean age at diagnosis of PNH was 46 years and the mean interval between the diagnoses of PNH and AL was 53 months. AL type was AML M6 in 8 patients, other types of AML in 12 and ALL in one, with a mean survival of 7.1 months following diagnosis of AL. In all cases analyzed, the PNH phenotype of erythrocytes disappeared with progression of AL, whereas reappearance of this phenotype with complete remission of AL was inconstant. PNH would thus appear to be a potential preleukemic disease. When this disorder terminates in AL, the type is often AML M6, although ALL is also possible. The prognosis of AL in PNH is poor as for other secondary leukaemias. Apart from marrow aplasia, leukaemic transformation is another life threatening complication of PNH which may justify allogeneic bone marrow transplantation (allo-BMT) and potential leukaemic transformation can therefore be an additional argument in favour of allo-BMT when pancytopenia develops in PNH patients.
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PMID:Acute leukaemia in paroxysmal nocturnal haemoglobinuria. Case report and review of the literature. 897 94

Apoptosis induced by effector cells of the immune system or by cytotoxic drugs is a main mechanism mediating the prevention or elimination of tumoral cells. For instance, the human T-cell leukemia Jurkat is sensitive to Fas-induced apoptosis and to activation-induced cell death (AICD), and the promonocytic leukemia U937 is sensitive to Fas- and TNF-induced apoptosis. In this work, we have analyzed the mechanisms of resistance to physiological or pharmacological apoptosis in human leukemia by generating highly proliferative (hp) sub-lines derived from Jurkat and U937 cells. These hp sub-lines were resistant to Fas- and TNF-induced apoptosis, as well as to AICD. This was due to the complete loss of Fas and TNFR surface expression and, in the case of Jurkat-derived sub-lines, also of CD3, CD2 and CD59 molecules. The sub-lines also completely lacked the expression of the apoptotic protease CPP32, present in parental cells. Moreover, these sub-lines were no longer sensitive to doxorubicin-induced apoptosis, which was efficiently blocked by the general caspase inhibitor Z-VAD-fmk in the parental cell lines. These data suggest a molecular mechanism for the development of resistance of leukemic cells to physiological and pharmacological apoptosis inducers, giving rise to highly proliferative tumoral phenotypes. These results also indicate that Fas and CPP32 could be useful prognostic markers for the progression and/or therapy outcome of human leukemias.
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PMID:Resistance to apoptosis correlates with a highly proliferative phenotype and loss of Fas and CPP32 (caspase-3) expression in human leukemia cells. 945 11


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