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)

Protein kinase C (PKC) activation and/or modulation of its isoenzyme expression play key roles in regulating the response of haematopoietic cells to both growth factors and non-physiological inducers of cell growth and differentiation. The level of PKC activities for both cytosol and particulate fractions of ALL and CLL cells are lower than those of AML type. Atypical AML blasts expressing T-cell associated CD2 and CD7 determinants have significantly lower PKC activities compared to typical AML blasts. Analyses of PKC isoforms (-alpha, -beta, and -gamma) show considerable variation with respect to leukaemic cell distributions and subcellular localisations. PKC-alpha and -beta are usually the major species in cytosolic fractions, whereas PKC-gamma is the predominant type in particulate fractions. All lymphoid cells express PKC-gamma in the cytosol, albeit as a minor component, while the occurrence of cytosol PKC-gamma in AML cells appears to be associated in particular with a typical lymphoid antigen expression.
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PMID:The expression and possible roles of protein kinase C in haematopoietic cells. 133 6

Classical multidrug resistance is characterized by overexpression of a membrane protein, P-glycoprotein, which acts like a drug-extruding pump, reducing accumulation of cytotoxic drugs inside malignant cells. We have developed a simple method for detecting an intracellular epitope of P-glycoprotein in normal and leukemic cells by the monoclonal antibody JSB-1 and fluorescence-activated flow cytometry. Permeabilization of blood and bone marrow cells in unprocessed samples is achieved by a commercially available red blood cell lysing solution which excellently preserves the light scatter properties of leukocytes. The method is suitable for analyzing samples in clinical routine. Lower than 1% reactivity was seen in the lymphoid gate of normal peripheral blood and bone marrow samples as compared with over 60% of reacting cells in some leukemic samples. Twelve patients with acute de novo leukemia were studied at presentation, 13 patients at a refractory stage, and 28 in remission. There was a positive correlation between the P-glycoprotein and the CD34 expression in acute myelogenous leukemia and an association between the P-glycoprotein expression and the blast count in both acute myelogenous and lymphatic leukemias.
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PMID:Flow cytometric analysis of P-glycoprotein in normal and leukemic cells. 135 49

We herein describe an unusual case of acute myeloid leukaemia (AML) showing strong cytochemical reactivity for myeloperoxidase (MPO) but surprisingly no reactivity using flow cytometry for any of the lineage-specific cell surface markers, i.e. myelomonocytic antigens CD13, CD14 and CD33; or B-lymphoid antigens CD19, CD20 and immunoglobulins; or T-lymphoid antigens CD2, CD3 and CD5. The strong reactivity for MPO and the complete absence of reactivity for CD13 and CD14 was verified by an independent assay involving alkaline phosphatase-anti-alkaline phosphatase (APAAP). Our case is of interest for at least two reasons: First, a poorly differentiated variant of AML (negative for MPO but positive for one or more of the myeloid-lineage CD antigens) has been designated FAB M0. In terms of the expression of phenotypic markers, our case may be considered as an 'MPO (+), CD antigen (-) AML'. The CD antigens are known to be expressed very early during myeloid differentiation whereas MPO (in its functional form) is viewed as being expressed relatively late in the process. It is therefore intriguing from a biological standpoint why the supposedly early antigens (CD33 and CD13) remain unexpressed; this may represent an example of 'asynchronous differentiation' in leukaemia. Second, from a practical standpoint, the use of immunophenotyping as a first-line diagnosis would fail to detect such cases. This case strengthens the notion that immunophenotyping by flow cytometry does not eliminate the necessity of performing peroxidase cytochemical staining.
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PMID:Acute myeloid leukaemia with an unusual phenotype: myeloperoxidase (+), CD13 (-), CD14 (-) and CD33 (-). 138 46

FLT3, a receptor belonging to the FMS/KIT family and localized to 13q12, could play a role in the biology of early hematopoietic progenitor cells. Because FMS and KIT are expressed in both normal progenitors and myeloid leukemias, we looked for FLT3 expression in fresh human leukemic cells using Northern blot analysis. High levels of FLT3 expression were detected in 92% of the cases of acute myeloid leukemia (AML) tested, ranging from the M1 to the M5 stages of differentiation assessed in the French-American-British classification. Immature (MO) AML cells, biphenotypic leukemias, and AML with megakaryocytic differentiation (M7 subtype) also expressed the FLT3 transcript. FLT3 was also expressed at high levels in acute lymphoid leukemias of T and B origins. Finally, it was not expressed in chronic myeloid leukemias in chronic phase, whereas it was expressed in most blast crisis samples. This pattern of expression of FLT3 contrasts with the expression of FMS and KIT restricted to myeloid leukemias, and suggests that the FLT3 product could play a role in the expansion of the leukemic blasts of both the myeloid and lymphoid lineages.
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PMID:Expression of the FMS/KIT-like gene FLT3 in human acute leukemias of the myeloid and lymphoid lineages. 138 91

Thymoma is associated with a wide variety of syndromes. However, an association with peroxidase-negative acute myeloid leukemia and pinealoma, although feasible due to the marked influence of this tumor on the lymphoid system, has not been described previously. A patient with thymic carcinoma and pinealoma who developed peroxidase-negative acute myeloid leukemia as a late event is presented in this report.
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PMID:Thymic carcinoma associated with pinealoma and terminating with peroxidase-negative acute myeloid leukemia. 139 88

Recent advances utilizing monoclonal antibodies to phenotype acute leukemias have revealed no prognostic significance of the expression of lymphoid-associated antigens by acute myeloid leukemia blasts and conflicting results regarding 'biphenotypic' acute myeloid leukemia. Several studies treating patients with refractory lymphoma with immunotoxins reported encouraging results but significant production of anti-mouse or anti-toxin antibody. Radiolabeled antibodies that react with panhematopoietic antigens have delivered selective radiation to marrow, spleen and lymph nodes in animal models and are being used in Phase I studies of marrow transplantation for acute leukemia.
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PMID:Monoclonal antibodies in the study and therapy of hematopoietic cancers. 141 32

This study is intended to establish biological correlation between the expression of lymphoid associated features in acute myeloid leukaemia (AML). In 62 AML patients, predominantly enrolled on Eastern Cooperative Oncology Group (ECOG) treatment protocols, in whom immunoglobulin (Ig) as well as T-cell receptor beta chain (TCR-beta) gene rearrangement analyses had been performed, morphology, cytochemistry, antigen profile and karyotype were reviewed retrospectively. Nuclear reactivity with anti-TdT antibody was demonstrated in 34 patients (55%) and confirmed by ribonuclease protection assay in all patients tested. Five TdT-protein negative patients were TdT-transcript positive. Lymphoid antigens (lyA) were detected in 24 of 51 cases tested (47%) with B-cell antigens (CD19, CD10) being restricted to TdT+ AML (P = 0.03). Only two patients had Ig heavy, none had Ig light chain or TCR-beta gene rearrangements. Although both patients with rearranged Ig loci were TdT+, either by protein or RNA analysis, the low incidence of such rearrangement within the TdT+ AML group (6%) argues against a significant association between the presence of TdT and crosslineage Ig gene rearrangements in AML. While FAB-diagnoses did not differ between TdT+ and TdT- or lyA+ and lyA- AML, particular immunophenotypic features correlated with TdT positively, e.g. the presence of early antigens, CD34 and HLA-DR, and the absence of the more mature myelo-monocytic antigens, CDw65 and CD14. Certain cytogenetic abnormalities were associated with TdT+ AML such as inv(16) (p13q22) or t(16;16) (p12;q22) (five patients; P = 0.03) and t(8;21) (q22;q22) (three patients). A greater number of TdT- than TdT+ AML patients had only normal karyotypes (P = 0.06). Neither immunophenotypic nor karyotypic correlations could be established for lyA+ AML.
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PMID:Lymphoid lineage-associated features in acute myeloid leukaemia: phenotypic and genotypic correlations. 141 14

The aim of this study was to investigate to which extent acute leukemias could be monitored for residual disease by using atypical antigen combinations as leukemia-related markers. Atypical antigenic features were determined by double color flow cytometry and included coexpression of lymphoid and myeloid related antigens, unphysiological coexpression of immature and mature antigens, and lack of an antigen that is normally expressed during maturation. Atypical immunophenotypes were detected in 35 of 68 patients with AML (51.5%) and 15 of 24 patients with ALL (62.5%). When 12 patients with leukemia-associated markers were again analyzed at relapse, the relevant antigen combinations were retained in 11 of them. The sensitivity of this two color flow cytometric assay as determined in dilution experiments was 1 in 10(3) to 10(4) cells. Follow-up studies of bone marrow samples revealed that, after induction chemotherapy cells with leukemia-associated markers were detectable in several patients at a frequency of 0.5 to 4%, but only patients in whom the cells with atypical antigens never disappeared suffered from relapse. In contrast, patients who became negative for the atypical cells remained in complete remission (median remission duration after the first negative bone marrow assessment by flow cytometry 52 weeks, range 20-102). We conclude that atypical antigen combinations, which are present in a meaningful number of acute leukemias, are a valuable means of monitoring acute leukemia patients during follow-up. This flow cytometric approach can complement other strategies to get a more accurate definition of remission in acute leukemia.
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PMID:Flow cytometric determination of atypical antigen expression in acute leukemia for the study of minimal residual disease. 145 6

Thirty cases of newly diagnosed pediatric acute myeloblastic leukemia (AML) with French-American-British (FAB) M2 morphology were analyzed with cytogenetics and a comprehensive panel of monoclonal antibodies reactive with lymphoid-, natural killer (NK)-cell-, and myeloid-associated antigens. The t(8;21)(q22;q22), or t(8;21;V)(q22;q22;V), translocation was identified in 16 of the 30 cases. Cases with the t(8;21) did not differ significantly from the remaining M2 cases with respect to expression of CD11b, CD13, CD14, CD15, CD33, CD34, CD36, CD41a, CD42b, CDw65, TdT, or HLA-DR. Expression of the B-cell antigen CD19 was detected in 13 of the 16 t(8;21) cases (81%), but in only 1 of the 14 (7%) other M2 cases (P = .00006). Expression of the CD56 NK-cell antigen was also significantly more frequent among t(8;21) cases (63% v 14%; P = .01). Coexpression of CD19 and CD56 was found only in the t(8;21) group (9 of 16 cases, P = .0009). Furthermore, this phenotype was not found in 48 evaluable cases of de novo AML of the FAB M1, M3, M4, M5, or M7 subtypes. The 14 M2 AML cases lacking the t(8;21) commonly expressed CD2 (n = 5) or CD7 (n = 8). However, no case with the t(8;21) expressed either antigen (P = .01 and .0005, respectively). Thus, the t(8;21) biologic subgroup of pediatric M2 AML has distinct immunophenotypic characteristics that distinguish it from other types of de novo AML.
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PMID:Distinctive immunophenotypic features of t(8;21)(q22;q22) acute myeloblastic leukemia in children. 846 84

By using monoclonal antibodies against lymphoid and myeloid differentiation antigens, surface marker analysis was performed on the tumor cells from 42 patients with acute leukemia and lymphoblastic lymphoma. Nine (21%) of 42 cases were diagnosed biphenotypic leukemia. Two (17%) of the 12 patients with acute myeloid leukemia, four (18%) of 22 with acute lymphocytic leukemia and three (38%) of 8 with lymphoblastic lymphoma expressed both lymphoid and myeloid antigens. Tumor cells from six patients expressed both T-cell and myeloid antigens, and those from three other expressed both B-cell and myeloid antigens. Southern blot analysis was performed on the DNA from four patients with biphenotypic leukemia cells expressing T-cell and myeloid antigens. DNA from one patient showed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene, and that from one other showed clonal rearrangement of both IgH gene and T-cell receptor beta-chain gene. DNA from two other patients showed a germline configuration of both genes. These results indicate that biphenotypic leukemia, especially T-cell and myeloid phenotype, is not so rare in acute leukemia and lymphoblastic lymphoma. The results of immunogenotypic analysis were not consistent with those of immunophenotypic analysis in biphenotypic leukemia.
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PMID:[Immunophenotypic and immunogenotypic analyses of acute leukemia and lymphoblastic lymphoma expressing myeloid and lymphoid antigens]. 150 95


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