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)

Three DNA damage-responsive cell cycle checkpoints can be shown to operate in diploid human fibroblasts. One checkpoint arrests growth in G1, another inhibits replicon initiation in S phase cells, and the third delays progression from G2 into mitosis. Progression from G2 into M is controlled in part by a cyclin-dependent kinase (cyclin B/Cdk1) that is regulated by tyrosine phosphorylation. Phosphorylation of Tyr15 on Cdk1 is inhibitory for kinase activity. Activation of cyclin B/Cdk1 at the onset of mitosis is accomplished by a phosphatase, Cdc25C, that interacts with cyclin B/Cdk1 in an autocatalytic feedback loop to remove the inhibitory phosphate at Tyr15 and activate kinase activity. DNA damage triggers G2 delay by inhibiting formation of the autocatalytic feedback loop so that dephosphorylation of Tyr15 does not occur. This suppression of activation of cyclin B/Cdk1 appears to account for the failure of damaged G2 cells to progress into mitosis. Once the damage to DNA is repaired, cells resume progression into mitosis as the cycle is re-engaged. The isoflavone genistein inhibits tyrosine kinases, including one that phosphorylates Cdk1 on Tyr15. This kinase, p56/p53lyn is rapidly induced by treatments that trigger cell cycle checkpoints (ionizing radiation, cytosine arabinoside), suggesting that this kinase may actively delay the onset of mitosis by phosphorylating Tyr15 on Cdk1. Genistein also inhibits type II DNA topoisomerase to produce a form of DNA damage that triggers all of the DNA damage-responsive cell cycle checkpoints. A brief 10 min incubation with the topoisomerase poison amsacrine was sufficient to trigger the S phase checkpoint response and inhibit replicon initiation. Inhibition of replicon initiation by 1 microM amsacrine was maximal 20-30 min after drug treatment and by 120 min, the checkpoint response had decayed to allow near control rates of replicon initiation. Topoisomerase II poisons also are powerful clastogens inducing lethal and carcinogenic chromosomal aberrations. Type II topoisomerase can break DNA in a region of chromosome 11q23 that contains the ataxia telangiectasia gene (ATM). The ATM gene controls all of the DNA damage-responsive cell cycle checkpoints. Chromosomal aberrations in 11q23 are frequently seen in acute myeloid leukemia that develops as a consequence of etoposide chemotherapy. Thus, topoisomerase poisons such as genistein may trigger chromatid breakage to inactivate AT gene function, disable cell cycle control, and induce genetic instability.
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PMID:Human topoisomerase II function, tyrosine phosphorylation and cell cycle checkpoints. 949 43

The sequential administration of fludarabine followed by cytosine arabinoside (ara-C) has demonstrated significant synergistic effects against the CEM human leukemic cell line. This in vitro synergism was investigated in a Phase I trial in pediatric patients with relapsed acute leukemia. The optimum concentrations of 9-beta-D-arabinofuranosyl 2-fluoroadenine and ara-C necessary to achieve significant drug synergism from in vitro studies were between 10 and 20 microM. Fludarabine was infused at a dose to attain a target plasma concentration of 10 microM for 48 h, followed by a continuous infusion of escalated ara-C doses to maintain plasma ara-C concentrations of 10, 12.5, 15, or 17.5 microM for 72 h. Thirteen patients with acute lymphocytic leukemia and 18 with acute myelocytic leukemia were entered into the study, 30 of whom were clinically evaluable for toxicity. Pharmacokinetic and pharmacodynamic studies were performed on specimens from 20 patients. The optimal 9-beta-D-arabinofuranosyl 2-fluoroadenine and ara-C concentrations in plasma were easily achieved after continuous infusion regimens of both drugs. Cellular ara-CTP is augmented 5-8-fold in leukemic cells from patients receiving fludarabine phosphate treatment followed by ara-C. The maximum tolerated plasma concentrations for this combination regimen was 10 microM fludarabine for 48 h followed by 72 h of 15 microM ara-C, which were achieved at dose level 3. A significant number of responses were also seen. Nine of 18 evaluable patients (50%) with acute myelocytic leukemia achieved complete or partial responses, and 3 of 9 evaluable patients with acute lymphocytic leukemia achieved complete or partial responses. Fludarabine and ara-C successfully eradicated bone marrow disease in 16 of 27 patients (59%), 23 patients of which had been treated previously with high-dose ara-C. These results verified the synergistic effect fludarabine exhibited in augmenting ara-CTP concentrations in patients' leukemic blasts, thus improving the clinical response in relapsed pediatric leukemias.
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PMID:Pharmacokinetic and pharmacodynamic studies of fludarabine and cytosine arabinoside administered as loading boluses followed by continuous infusions after a phase I/II study in pediatric patients with relapsed leukemias. The Children's Cancer Group. 1003

Acute tumor lysis syndrome (ATLS), a condition which results from a rapid destruction of tumor cells with massive release of cellular breakdown products, has been well described following the treatment of various malignancies. However, only a handful of cases of spontaneous ATLS have been reported in the literature. We describe the first reported case of spontaneous ATLS in acute myeloid leukemia (AML). A previously healthy 63 year old woman presented with a two month history of fatigue and a one week history of easy bruising. On admission she had oliguric acute renal failure, with marked elevation in serum uric acid and phosphate. A bone marrow biopsy showed AML M7 with fibrosis. The renal failure resolved with supportive care and institution of allopurinol therapy. Following this, AML induction chemotherapy resulted in complete remission. Her biochemical and clinical course were very similar to the classical ATLS seen in patients after chemotherapy. Therefore, this case represents a rare instance of acute renal failure from spontaneous ATLS, and in our opinion the first reported occurrence of spontaneous ATLS associated with AML.
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PMID:Spontaneous acute tumor lysis syndrome in acute myeloid leukemia? A single case report with discussion of the literature. 964 77

This report describes the analysis of culture cells and blast cells separated from the heparinized bone marrow and whole blood of patients with acute leukemias by means of a density-gradient technique (Ficoll-sodium metrizoate d = 1.077 g/cm3). Cell-surface antigens were analyzed by a fluorescence-activated cell sorter using a panel of monoclonal antibodies (MAbs). The blast cells and culture cells were fixed by 3% paraformaldehyde in phosphate-buffered saline. A low level of expression of MPO precursor protein was found in THP-1. K-562 and HEL, MEG-01, erythro-megakaryocytic leukemia cell lines, Jurkat, MOLT-3, MOLT-4, RPM18402, ATL-5, T-cell leukemia cell lines, Raji, Daudi. BALL-1, B-cell leukemia cell lines, and AGNK1 showed negative reaction. The de novo MPO-negative acute leukemias, middle level of expression of MPO precursor protein, was found in the blasts of MPO-negative AML (AML, M0), which coexpressed CD13, CD33, CD34, and CD38. A high level of expression of MPO protein was found in all cases of AML, M1, and M2. The MPO expression was not found in all cases of acute lymphoblastic leukemia. The highest level of MPO expression was found in cases of AML, M3, and AML, M3v, suggesting the diagnostic value for this type of leukemia. The detection of MPO precursor protein by flow cytometric analysis with monoclonal antibodies is essential for the determination of lineage and precise diagnosis of acute unclassifiable leukemia, and should contribute substantially to the development of an effective form of therapy and cure.
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PMID:Sensitive detection technique of myeloperoxidase precursor protein by flow cytometry with monoclonal antibodies. 966 78

A patient suffering from acute myeloid leukemia (FAB M5a) received a PBSC allograft from a matched, related donor. On day 13 after transplantation severe hypophosphatemia (0.21 mmol/l) was first noted which persisted irrespective of intravenous phosphate administration, and within 2 days reached concentrations below 0.13 mmol/l. After repeated phosphate substitution serum phosphate returned to 1.40 mmol/l on day 17. Phosphate in urine, and calcium in serum were recorded as unchanged throughout. Clinical signs and symptoms due to severe hypophosphatemia were not observed except for paresthesia in the lower extremities. The precipitous fall in serum phosphate coincided with hematopoietic reconstitution as reflected by a steep rise in leukocyte count from 0.08 x 109/l on day 10 to 5. 94 x 109/l on day 15 after transplantation. Thus, isolated hypophosphatemia was likely the result of excessive cellular phosphate uptake during hematopoietic reconstitution. Electrolyte monitoring after PBSCT should include serum phosphate to identify the hypophosphatemia associated with hematopoietic recovery.
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PMID:Severe hypophosphatemia during hematopoietic reconstitution after allogeneic peripheral blood stem cell transplantation. 1080 74

The primary objective of this study was to determine the complete remission (CR) rate achieved with the FLAG (fludarabine phosphate, cytarabine and granulocyte colony-stimulating factor) regimen in patients with relapsed or refractory acute myeloid leukaemia (AML) or de novo refractory anaemia with excess of blasts in transformation (RAEB-t). Secondary objectives were to evaluate survival and toxicity. Induction treatment consisted of between one and two courses of FLAG. Patients achieving CR received between one and two courses of consolidation treatment. Eighty-three of the 89 patients entering the study were eligible for assessment. CR rates were: 17 out of 21 (81%) in late relapse AML (Group 1), 13 out of 44 (30%) in early relapse/refractory AML (Group 2), and 10 out of 18 (56%) in de novo RAEB-t (Group 3). Thirty-four of the 40 responders (85%) achieved CR after one induction course. Median survival times were 1.4 years, 3 months and 1.6 years in Groups 1, 2 and 3 respectively. Other than myelosuppression, the FLAG regimen was not generally associated with clinically significant toxicity and was well tolerated by most patients including the elderly. The FLAG regimen offers a very effective alternative treatment for CR induction in poor prognosis adult patients with either relapsed or refractory AML or de novo RAEB-t. FLAG delivers high-dose treatment without increasing overall toxicity, an approach which is of particular value in older patients, who constitute the majority in these diseases. It is therefore an important advance in developing new treatment options for these patients.
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PMID:A multicentre, open, non-comparative phase II study of a combination of fludarabine phosphate, cytarabine and granulocyte colony-stimulating factor in relapsed and refractory acute myeloid leukaemia and de novo refractory anaemia with excess of blasts in transformation. 1116 93

The erythrocyte skeleton plays an essential role in determining the shape and deformability of the red cell. Disruption of the interaction between components of the red cell membrane skeleton may cause loss of structural and functional integrity of the membrane. Several observations based on studies in vitro strongly suggest that phosphorylation may modify interactions between proteins, leading to a reduced affinity. In particular, increased phosphorylation of beta-spectrin decreases membrane mechanical stability. In order to investigate the presence of membrane protein defects we investigated the erythrocyte membrane protein composition and phosphorylation in 22 children with leukemia at diagnosis and during the remission phase. Sixteen children had acute lymphoblastic leukemia (ALL), three had chronic myeloid leukemia (CML) and three had acute myeloid leukemia (AML). Ten patients (eight ALL and two CML) displayed elliptocytosis and poikilocytosis, an increase of spectrin dimers (41.8 +/- 15.6) and an enhanced phosphorylation of beta-spectrin (108 +/- 15%) at diagnosis. These alterations disappeared during the remission phase. This is the first demonstration of a reversible erythrocyte membrane alteration in leukemia. Since the beta-spectrin phosphate sites are located near the C-terminal region and close to the head of the beta-chain that is involved in dimer-dimer interaction, we supposed that the beta-chain phosphorylation has an effect upon the interactions between spectrin dimers, ie the tetramerization process. The weakening of this process should be responsible for the presence of elliptocytes and poikilocytes as reported in hereditary elliptocytosis and pyropoikilocytosis.
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PMID:Reversible erythrocyte skeleton destabilization is modulated by beta-spectrin phosphorylation in childhood leukemia. 1123 68

A 62-year-old female was admitted to our hospital with suspected acute leukaemia and after investigation we diagnosed acute myeloblastic leukaemia (AML-M1). The patient's blood type was found to be the very rare Bombay type and surveillance of her relatives showed the same blood type in her male cousin on her mother's side. Alongside chemotherapy the patient received 4000 ml of frozen Bombay-type red cells, 1400 ml of concentrated red cells in manitol adenine phosphate solutions and 360 units of type O concentrated platelets without marked effects. The anti-H antibody was initially at 128 dilution but for unknown reasons increased to 2048 dilution after remission of AML-M1. About 3 months after hospitalization the patient died of Cryptococcus neoformans pneumonia despite strict precautions against infection. Although AML-M1 is a common adult leukaemia and is chemosensitive to anti-leukaemic drugs, neither AML-M1 in a patient with Bombay-type red cells nor its treatment with chemotherapy and transfusion with type Oh frozen red cells have previously been reported.
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PMID:Treatment of acute myeloblastic leukaemia in a patient with Bombay blood type: a case report. 1139 47

The anthracycline daunorubicin is widely used in the treatment of acute nonlymphocytic leukemia. The drug has, of course, been the object of intense basic research, as well as preclinical and clinical study. As reviewed in this article, evidence stemming from this research clearly demonstrates that cell response to daunorubicin is highly regulated by multiple signaling events, including a sphingomyelinase-initiated sphingomyelin-ceramide pathway, mitogen-activated kinase and stress-activated protein/c-Jun N-terminal kinase activation, transcription factors such as nuclear factor kappa B, as well as the Fas/Fas-ligand system. These pathways are themselves influenced by a number of lipid products (diacylglycerol, sphingosine-1 phosphate, and glucosyl ceramide), reactive oxygen species, oncogenes (such as the tumor suppressor gene p53), protein kinases (protein kinase C and phosphoinositide-3 kinase), and external stimuli (hematopoietic growth factors and the extracellular matrix). In light of the complexity and diversity of these observations, a comprehensive review has been attempted toward the understanding of their individual implication (and regulation) in daunorubicin-induced signaling. (Blood. 2001;98:913-924)
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PMID:Signaling pathways activated by daunorubicin. 1149 33

Lovastatin is an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the major regulatory enzyme of the mevalonate pathway. We have previously reported that lovastatin induces a significant apoptotic response in human acute myeloid leukemia (AML) cells. To identify the critical biochemical mechanism(s) essential for lovastatin-induced apoptosis, add-back experiments were conducted to determine which downstream product(s) of the mevalonate pathway could suppress this apoptotic response. Apoptosis induced by lovastatin was abrogated by mevalonate (MVA) and geranylgeranyl pyrophosphate (GGPP), and was partially inhibited by farnesyl pyrophosphate (FPP). Other products of the mevalonate pathway including cholesterol, squalene, lanosterol, desmosterol, dolichol, dolichol phosphate, ubiquinone, and isopentenyladenine did not affect lovastatin-induced apoptosis in AML cells. Our results suggest that inhibiting geranylgeranylation of target proteins is the predominant mechanism of lovastatin-induced apoptosis in AML cells. In support of this hypothesis, the geranylgeranyl transferase inhibitor (GGTI-298) mimicked the effect of lovastatin, whereas the farnesyl transferase inhibitor (FTI-277) was much less effective at triggering apoptosis in AML cells. Inhibition of geranylgeranylation was monitored and associated with the apoptotic response induced by lovastatin and GGTI-298 in the AML cells. We conclude that blockage of the mevalonate pathway, particularly inhibition of protein geranylgeranylation holds a critical role in the mechanism of lovastatin-induced apoptosis in AML cells.
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PMID:Blocking protein geranylgeranylation is essential for lovastatin-induced apoptosis of human acute myeloid leukemia cells. 1151


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