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)

The rapid degradation and subsequent lack of efficacy of n-butyric acid in vivo has been improved by the synthesis of monosaccharide stable pro-drugs of butyric acid. We studied the effects of D1 (O-n-butanoyl-2,3-O-isopropylidene-alpha-D-mannofuranoside), G1 (1-O-n-butanoyl-D,L-xylitol), and F1 (1-O-n-butanoyl 2,3-O-isopropylidene-D,L-xylitol) on the maturation and proliferation of AML cell lines HL 60 and FLG 29.1 and of purified blast cells from 10 cases of de novo acute myeloid leukaemia (AML). AML cell maturation was measured by surface antigen expression, morphology and cytochemistry. Toxicology in mice was also evaluated (DL50 1000 mg/kg). In HL 60 cells G1 and D1 increased the expression of CD15 and CD11a (presenting 62% of promyelo-metamyelocytes), and in 7/10 cases of primary AMLs that of CD11a, CD11b, CD15, and myeloperoxidase. D1, G1 and F1 induced a dose-dependent inhibition of tritiated thymidine uptake. Apoptosis (evaluated by flow cytometry and agarose gel electrophoresis) was induced in AML blasts by D1 and F1 (79% and 94% respectively for HL 60 cells) and, with less effect, by G1 (27%). The persistence of maturative and apoptotic activity in these new pro-drugs of butyric acid, hydrolysed only inside the tumour cell, suggests a possible use in differentiation therapy of myelodysplastic syndromes and AMLs.
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PMID:Butyrate-stable monosaccharide derivatives induce maturation and apoptosis in human acute myeloid leukaemia cells. 963 98

Translation of mRNA is a prerequisite for cell proliferation, differentiation and viability. We have studied the effect of ribosome protein factors (GPRE) on acute myeloid leukemia (AML) blast cells. Ribosomes were isolated from MPC-11 cells using ultra-centrifugation. GPRE were extracted using a high KCl procedure. Blast cells from six AML patients were grown in suspension cultures for 24 and 96 h. GPRE or granulocyte macrophage-colony stimulating factor (GM-CSF) were added at the start of the incubation. GPRE, but not GM-CSF, prevented chromatin condensation and fragmentation of blast cell nuclei in AML-M2, -M4 and -M5 and the loss of nucleoli in AML-M2 and -M5. The fraction of phagocytosing blast cells in AML-M1, -M2, -M4 and -M5 was increased by GPRE. GPRE stimulated opsonin-dependent and -independent attachment and internalisation of N. meningitidis. GPRE increased the fraction of blasts expressing CD11b and CD32 in AML-M2 and -M5. GPRE diminished the fraction of AML-M5 cells bearing CD35 and CD32. GPRE also decreased the fraction of CD11c-bearing AML-M2 and -M5 cells. GM-CSF potentiated effects of GPRE in AML-M1, -M2, -M4 and -M5. GPRE and GM-CSF in combination affected phagocytosis and surface antigen expression in blast cells that were not influenced by either factor alone. Neither GPRE nor GM-CSF induced terminal differentiation or DNA-synthesis. We conclude that GPRE affects AML blast cell morphology, function and surface molecule expression, possibly by inhibiting apoptosis. The effects of GPRE may be mediated by ribosomal proteins that regulate translation and modulate the subcellular distribution of mRNA species.
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PMID:Ribosomal proteins sustain morphology, function and phenotype in acute myeloid leukemia blasts. 966 38

Immunophenotypic findings from 14 patients affected by acute myeloid leukaemia (AML) with t(8;21) were compared to those obtained from 79 AML patients with normal or other aberrant karyotypes. Classic lineage markers, adhesion molecules, surface enzymes, stem-cell-related antigens and HLA-DR were investigated. Following evaluation by the Mann-Whitney test, we found that t(8;21) AMLs showed a significantly higher expression of CD19, CD34, CD56, CD45RA and CD54. Conversely, blasts from patients in the control group significantly expressed higher levels of CD45RO, CD33, CD36, CD11b and CD14. In order to split the data at the best cut-off point to achieve the most homogeneous subset with regard to cytogenetic pattern, i.e. t(8;21) or not, the CART (Classification and Regression Trees) method was applied. In the univariate analysis by CART, statistically significant differences were found when CD19 was dichotomized at 10%, CD34 at 37%, CD45RA at 84%, CD54 at 21%, CD56 at 12%, CD36 at 14%, CD45RO at 25%, CD11b at 18% and CD14 at 12%. Once cut-off points were established by CART, we applied the logistic regression model to establish which combination of two or more antigens was most predictive for t(8;21). The combination CD19-CD34 at the cut-off points indicated above correctly classified 92/93 cases (98.9%). The addition of any other antigen combination to the CD19/CD34 model failed to improve the level of prediction. We conclude that AML with t(8;21) displays an exclusive immunophenotype that is highly predictive of the cytogenetic pattern.
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PMID:Immunophenotypic analysis enables the correct prediction of t(8;21) in acute myeloid leukaemia. 969 58

The translocation (8;21)(q22;q22) is a karyotypic abnormality detected in acute myeloid leukaemia (AML) M2 and results in the formation of the chimeric fusion gene AML1/MTG8. We previously reported that two hammerhead ribozymes against AML1/MTG8 cleave this fusion transcript and also inhibit the proliferation of myeloid leukaemia cell line Kasumi-1 which possesses t(8;21)(q22;q22). In this study, we investigated the mechanisms of inhibition of proliferation in myeloid leukaemic cells with t(8;21)(q22;q22) by ribozymes. These ribozymes specifically inhibited the growth of Kasumi-1 cells, but did not affect the leukaemic cells without t(8;21)(q22;q22). We observed the morphological changes including chromatin condensation, fragmentation and the formation of apoptotic bodies in Kasumi-1 cells incubated with ribozymes for 7 days. In addition, DNA ladder formation was also detected after incubation with ribozymes which suggested the induction of apoptosis in Kasumi-1 cells by the AML1/MTG8 ribozymes. However, the ribozymes did not induce the expression of CD11b and CD14 antigens in Kasumi-1 cells. The above data suggest that these ribozymes therefore inhibit the growth of myeloid leukaemic cells with t(8;21)(q22;q22) by the induction of apoptosis, but not differentiation. We conclude therefore that the ribozymes targeted against AML1/MTG8 may have therapeutic potential for patients with AML carrying t(8;21)(q22;q22) while, in addition, the product of the chimeric gene is responsible for the pathogenesis of myeloid leukaemia.
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PMID:Induction of apoptosis in myeloid leukaemic cells by ribozymes targeted against AML1/MTG8. 1018 72

Activity and expression of four major protein serine/threonine (Ser/Thr) phosphatases, protein phosphatase type 1 (PP1), protein phosphatase type 2A (PP2A), protein phosphatase type 2B (PP2B) and protein phosphatase type 2C (PP2C) were evaluated in normal peripheral leukocytes, and in various leukemic cells from patients with acute myelogenous leukemia (AML), common acute lymphocytic leukemia (cALL), or chronic lymphocytic leukemia (CLL). PP1 was the most abundant phosphatase in blood cells, and relative abundance of each phosphatase was: PP1 > PP2A > PP2B approximately = PP2C. PP1 activity and its expressions were higher in blasts of AML-M4 and -M5 than in cells of AML-M1, cALL and CLL. PP2A activity and its expression were higher in blasts of AML-M3, -M4 and -M5 than in cells of AML-M1, cALL and CLL. Activity and expression of both PP1 and PP2A in normal monocytes were highest, and PP2A activity in normal neutrophils was lowest among normal leukocytes. PP2B activity and its expression were higher in blasts of AML-M2, -M3 and normal lymphocytes. PP2C activity and its expression were relatively constant in various leukemic cell types. Activities of PP1 and PP2A of AML blasts correlated positively with the expression of CD11b, whereas activities of PP1 and PP2B correlated negatively with the expression of CD7. Thus, each phosphatase was ubiquitously but differently expressed in various leukemic cell types and in normal leukocytes. These data also suggest that expressions of PP1, PP2A and PP2B are relatively low in leukemic blasts arresting at the stage of early pluripotent stem cells, and are differently modulated during the course of myelomonocytic commitment and maturation.
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PMID:Expressions of four major protein Ser/Thr phosphatases in human primary leukemic cells. 1021 67

A new myeloid cell line, MTT-95, was established from the bone marrow of a patient with acute myelogenous leukemia (AML, M7). MTT-95 cells differentiate into mature basophilic cells in culture medium with no chemical component or cytokine. Surface phenotypes were as follows: CD11b 79.3%, CD13 92.4%, CD33 99.8%, CD34 87.9%, CD41a 77.6% and HLA-DR 0.3%. MTT-95 cells were strongly positive for glycoprotein IIb/IIIa by immunohistochemical staining and revealed metachromatic granules. MTT-95 cells seem to possess characteristics of both megakaryocytes and basophils. These findings suggest that MTT-95 cells are basophil progenitors. MTT-95 cells might be useful in the study not only of the biological aspects of basophils, but also of the diversities of AML (M7).
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PMID:Establishment of a new cell line (MTT-95) showing basophilic differentiation from the bone marrow of a patient with acute myelogenous leukemia (M7). 1035 25

Clinical and biological features were assessed in 204 consecutive de novo adult acute myeloid leukemia (AML) patients who received intensive chemotherapy regimens. Multiparameter flow cytometric assays both of the multidrug resistance (MDR-1)-associated P-glycoprotein (PGP) using the UIC2 monoclonal antibody (MoAb), and of terminal transferase (TdT) were performed. Cytogenetic findings were obtained from 196 patients with high resolution banding. At onset, UIC2 and TdT positivities were detected in 58.5% and 24% of cases, respectively. There were strict correlations either between UIC2 negativity and FAB M3 or between TdT and FAB M0-M1 (P = 0.001 and < 0.0001, respectively). On the other hand, age was significantly associated with cytogenetic risk classes (P < 0.0001). CD34 positivity was highly correlated with TdT expression (P < 0.0001). Moreover, CD7 and CD11b were significantly represented in UIC2+ subset (P < 0.0001). Rhodamine 123 (Rh 123) efflux was significantly higher in 75 UIC2 positive patients compared to 65 UIC2 negative ones (P < 0.001). As regards to cytogenetics, TdT positivity was strongly related either to t(9;22) or single/associated anomalies of chromosome 7; on the other hand, most or all cases with t(8;21) or t(15;17) were UIC2 or TdT negative, respectively. The rate of first complete remission (CR) differed both between UIC2+ and UIC2- cases and between TdT+ and TdT- ones (40% versus 72%, P < 0.001; and 36% versus 61%, P = 0.001, respectively). The survival rates (Kaplan-Meier method) were significantly shorter either in UIC2+ or in TdT+ patients (P = 0.005 and = 0.011, respectively). UIC2 and TdT negative cases showed longer remission duration (P = 0.03 and = 0.22, respectively). The additional effect of UIC2 and TdT on prognosis allowed us to identify two subsets of patients, the first [UIC2- TdT-] at better and the second [UIC2+ TdT+] at worse clinical outcome compared to single UIC2 and TdT cases, concerning CR (P < 0.001), survival (P < 0.0001) and CR duration (P = 0.007). The combinations [UIC2+ TdT-] and [UIC2- TdT+] showed an intermediate clinical course. A strong difference was found between poor risk and intermediate/favorable risk cytogenetic classes with regard to CR rate (P < 0.0001), overall survival and CR duration (P < 0.001). Nevertheless, within the poor risk class, UIC2 positivity was able to identify patients at worst prognosis with regard to CR (P = 0.005), survival (P = 0.02) and CR duration (P = 0.015). On the other hand, UIC2 and TdT negativity allowed us to distinguish patients with longer survival (P = 0.012 and = 0.04, respectively) and CR duration (P = 0.04 and = 0.025, respectively) within the intermediate/favorable risk class. The independent prognostic value of UIC2, TdT and cytogenetic risk classes was confirmed in multivariate analysis. These results suggest that PGP and TdT expressions, together with cytogenetic findings, may represent a basic predictor of chemotherapeutic failure in AML.
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PMID:P-glycoprotein and terminal transferase expression identify prognostic subsets within cytogenetic risk classes in acute myeloid leukemia. 1037 59

Lodgement, proliferation, and migration of leukemic cells within bone marrow (BM) microenvironment involves adhesion of these cells to the BM extracellular matrix molecules fibronectin and laminin. The 67-kDa laminin receptor (67LR) is a nonintegrin protein with high affinity for laminin, which plays a critical role in basement membrane invasion and metastasis of cancer cells. By Western blotting, we documented that 67LR was strongly expressed in myelomonocytic THP1 and histiocytic U937 cells and was weakly expressed in promyelocytic HL-60 cells. In HL-60 cells, 67LR expression almost disappeared after retinoic-induced granulocytic differentiation, whereas it strongly increased after phorbol ester-induced monocytic differentiation. We did not detect 67LR expression in normal BM hematopoietic cells, in precursor-B acute lymphoblastic leukemia, in chronic lymphocytic leukemia, or in chronic myeloid leukemia in chronic phase. By contrast, we detected enhanced 67LR expression in 40% of 53 de novo acute myeloid leukemias (AMLs), which frequently exhibited monocytic or myelomonocytic morphology and expressed CD14 and CD11a (P < 0.05). Using a colorimetric assay, we found that the expression pattern of this receptor corresponded to a higher adhesion to laminin; the adhesion was specific because in vitro addition to laminin-coated wells of recombinant 37-kDa laminin receptor precursor (37LRP), which is the cytoplasmic precursor containing both laminin-binding domains of cell surface 67LR, significantly reduced laminin binding of AML cells. The expression of 67LR on AML cell surface did not correlate with other differentiation and integrin antigens such as CD7, CD13, CD33, CD34, CD11b, CD11c, CD49d, CD49e, CD45RA, and CD45RO. In contrast with 67LR behavior in solid tumors, no statistically significant difference was found between 67LR expression and any hematological characteristic of the disease at diagnosis, nor between 67LR expression and outcome of the disease as measured by complete remission rate, disease-free survival, or overall survival. In conclusion, our results indicate that 67LR expression mediates specific adhesion to laminin and that the detection of this molecule may be a valuable addition to other lineage-associated antigens in identifying monocytic-oriented AML.
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PMID:Expression of the 67-kDa laminin receptor in acute myeloid leukemia cells mediates adhesion to laminin and is frequently associated with monocytic differentiation. 1038 34

Little is known of the functional status of blast cells from patients with acute myeloid leukaemia (AML). We have studied phagocytosis and membrane receptors by flow cytometry (FCM), and secretory activities in blast cells from 24 AML patients prior to treatment. Blast cells from 11/16 patients attached N. meningitidis, and internalization occurred in 7/14. The phagocytosis of zymosan particles and N. meningitidis correlated linearly (r = 0.9, p<0.01, n = 11). Surface membrane expression of CD32 and CD11b was sufficient to account for opsonin-dependent attachment in all except one patient. A significant fraction of the blast cells attached, but did not internalize meningococci. CD32 and CD11b were non-functional in all the blasts from five patients, and in a subpopulation from seven additional patients. Significantly more large than small blasts expressed CD32, CD35 and CD11b (p<0.001). Phagocytosis was unrelated to the secretion of IL-1alpha, IL-1beta, and TNFalpha. In conclusion, AML blast cell function is related to receptor expression, cell size and granularity, and to FAB-type.
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PMID:Functional differentiation of acute myeloid leukaemia blast cells. 1059 75

Arsenic trioxide (As2O3) is a useful drug for the treatment of acute promyelocytic leukemia (APL), acting through a complex mechanism involving the induction of apoptosis. We investigated by flow cytometry whether in vitro treatment of APL leukemic cells with As2O3 determined specific surface membrane changes. Twelve APL bone marrow aspirates were analyzed following 7 days of in vitro treatment with As2O3 (0.25, 0.5 and 2.5 microM) with regard to the expression of a series of differentiation antigens. Twelve acute myeloid leukemia (AML) samples of non-APL morphotype were analyzed as controls. Exposure of APL as well as non-APL samples to any concentration of As2O3 did not affect the expression of beta2 integrins (CD11a and CD11b), CD45 isoforms (RA, RB and R0), CD44/H-CAM, CD33 and the CEA-related antigen family members CD66ade and CD66b, thus failing to disclose any maturating effect. Of interest, in all APL samples (but not in AML) every tested dose of As2O3 determined a dramatic upregulation of CD66c display; intermediate concentration (0.5 microM) of As2O3 increased the median percentage of CD66c+ cells from 5% in control cultures (25th-75th percentile 2-12%) to 80% in drug-exposed cultures (25th-75th percentile 58-90%) (P<0.001). The induction of solitary expression of CD66c is a new finding which demonstrates As2O3 capability of generating phenotypic changes absolutely restricted to APL cells Moreover, these results provide experimental basis for considering the involvement of the newly described CD66 signalling pathway in As2O3-driven programmed cell death.
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PMID:In vitro exposure of acute promyelocytic leukemia cells to arsenic trioxide (As2O3) induces the solitary expression of CD66c (NCA-50/90), a member of the CEA family. 1067 75


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