Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A transforming N-ras gene has been cloned from acute myeloblastic leukemia bone marrow cells, in parallel with the N-ras gene derived from fibroblasts of the same patient. N-ras derived from fibroblasts lacked focus-forming activity in NIH/3T3 cells, indicating that gene activation in the leukemia cells must have occurred by a somatic event. Construction of chimeric molecules between the transforming and the normal N-ras genes and subsequent biological and sequence analysis of these constructs revealed that the transforming gene was altered by a point mutation changing amino acid 12 of the N-ras protein from glycine to aspartic acid.
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PMID:Activation of an N-ras gene in acute myeloblastic leukemia through somatic mutation in the first exon. 385 37

Cyclic administration of methotrexate (MTX) and L-Asparaginase (L-Asp) was utilized either as induction and maintenance chemotherapy or as maintenance chemotherapy alone following induction with other medications in treating 36 children with multiple relapses of acute leukemia. A complete remission rate (CR) of 67% was obtained in children with null-cell acute lymphocytic leukemia (ALL). The average length of remission was greater than four months. One of three patients with T-cell ALL and one of two patients with B-cell ALL achieved CR. In six cases of acute nonlymphocytic leukemia (ANLL), two patients achieved CR. One of two patients with terminal deoxynucleotidyl transferase (TdT) negative myeloblastic transformation of Ph'-positive chronic myelogenous leukemia (CML) obtained a CR lasting 20 weeks. Toxicity secondary to the chemotherapy included bone marrow suppression, hepatic injury, nausea, diarrhea, stomatitis, and allergic reactions to L-Asp. One case of subacute necrotizing leukoencephalopathy was seen.
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PMID:Methotrexate/L-asparaginase combination chemotherapy for patients with acute leukemia in relapse: a study of 36 children. 696 21

Patients who have received cytotoxic therapy for primary neoplastic disease are at an increased risk of developing secondary (therapy-related) acute myeloid leukaemia (AML) or myelodysplasia (MDS). RAS and FMS mutations have been observed in patients with AML and MDS. It has been suggested that the mutational status within these genes may be predictive of early secondary leukaemic disease. In this study we have screened 50 haematologically normal patients in complete remission from childhood acute lymphoblastic leukaemia (ALL) for activating point mutations in the RAS and FMS proto-oncogenes. Such patients may be considered at risk of therapy-related disease. Codons 12, 13 and 61 were screened in RAS and codon 969 in FMS using the polymerase chain reaction (PCR) followed by oligonucleotide hybridization (ONH). Three of the 50 patients (6%) were found to harbour N12 RAS mutations. One of these three patients (2%) had both a N12 RAS and FMS 969 mutation. Upon sequencing the RAS mutations, substitutions of serine, cysteine and aspartic acid for glycine were identified. The FMS 969 mutation was also confirmed, by sequencing, as a histidine substitution. RAS mutations were not detected in presentation samples indicating that these lesions have been somatically acquired presumably subsequent to cytotoxic therapy for the primary disease. Continued follow-up of these patients may indicate a role for these mutations in the development of secondary malignancies.
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PMID:RAS and FMS mutations following cytotoxic therapy for childhood acute lymphoblastic leukaemia. 756 28

One of the first known effects of the endogenous peptide N-acetyl-Ser-Asp-Lys-Pro (AcSDKP) is to inhibit entry into DNA synthesis of pluripotent haematopoietic stem cells (CFU-S) in mice. A specific anti-AcSDKP polyclonal antibody allows the level of the tetrapeptide by to be determined by enzyme immunoassay with good sensitivity and specificity. We present results demonstrating the presence of AcSDKP in humans: serum levels of 34 healthy controls were found to be between 0.7 and 2.5 pm/ml, regardless of age and sex. High levels were found in 44% of asymptomatic controls but only in 8% of AIDS patients out of a total of 37 patients with HIV. Subsequently, studies of serum levels were performed before treatment in 121 subjects with disorders of the nonlymphoid and the lymphoid lineages. Our results did not demonstrate any decrease in serum levels, however a moderate or marked increase was noted in one-third of the subjects, which was greater in disorders of the non-lymphoid lineages (48% of 72 patients) than the lymphoid lineage (21% of 50 patients). The most significant differences were observed between controls versus patients with myeloproliferative disorders (MPD, 24 patients: p < 0.001), controls versus patients with acute myelogenous leukaemia (AML, 15 patients: p < 0.02), as well as patients with AML versus patients with primary myelodysplastic syndromes (PMDS, 10 patients: p < 0.05). The pathophysiology of these abnormalities is discussed.
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PMID:Serum levels of a negative regulator of cell proliferation (AcSDKP) are increased in certain human haemopathies. 850 76

The tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP) is a physiological inhibitor of the proliferation of haematopoietic stem cells and progenitors. In Ara-C-treated mice, its plasmatic concentrations decrease while the CFU-S start cycling. Infusion of synthetic AcSDKP (Goralatide) at this time protects them from haematoxicity by blocking early cycling of CFU-S. Both in vitro and in vivo, this effect seems to be optimal in a narrow range of concentrations. Thus, a better knowledge of the kinetics of endogenous AcSDKP during cancer treatment could help to optimize the treatments with Goralatide. AcSDKP plasma levels have been measured by a specific EIA in 14 cancer patients during the two initial monthly 5 day courses of chemotherapy with 5-FU alone administered either by continuous infusions (six patients) or by 1 h daily infusions (eight patients). AcSDKP concentrations did not vary significantly during the first and the second course. Together with our previous results in AML patients treated with high doses chemotherapy (Ara-C and Anthracyclin), our present data suggest that the variations of endogenous AcSDKP in patients are dependent of the type, doses and schedule of chemotherapy.
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PMID:AcSDKP plasma concentrations in patients with solid tumours: comparison of two chemotherapeutic regimens. 902 62

Asp fI(18 kDa) and alkaline protease (33 kDa) are the 2 major antigens which are derived from Aspergillus (A.) fumigatus and have been implicated as possible virulence factors in the pathogenesis of Aspergillus-induced diseases. We attempted to detect fragments of genes encoding both proteins from fungus balls obtained at surgery or autopsy by polymerase chain reaction (PCR) amplification and then used PCR to test clinical samples. Frozen-stored fungus ball samples from a patient with acute myeloid leukemia complicated by Aspergillus pneumonia and from a patient with pulmonary aspergilloma were studied. We successfully amplified a 315 bp PCR product, the target sequence for Asp f I, and a 747 bp PCR product as a target sequence for alkaline protease (ALP) in both cases. In addition, 13 clinical samples including sputum specimens from patients with pulmonary aspergillosis were also examined. PCR analysis for the Asp f I (ALP) gene in clinical samples showed positive results in 5/10 (6/10) patients with pulmonary aspergilloma and in 3/3 (1/ 3) patients with invasive pulmonary aspergillosis. Culture data on A. fumigatus revealed positive results in 3/9 patients with pulmonary aspergilloma and in 2/3 patients with invasive pulmonary aspergillosis. This method can be used to recognize the involvement of A. fumigatus in various clinical settings where conventional culture results are not readily available.
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PMID:Polymerase chain reaction amplification of Asp f I and alkaline protease genes from fungus balls: clinical application in pulmonary aspergillosis. 905 95

A subset of patients with systemic mastocytosis (SM) develop acute myeloid leukaemia (AML). However, little is known about the biology of such leukaemias and their relationship to the mast cell (MC) lineage. We report on two female patients who suffered from SM and AML. According to FAB criteria, the leukaemias were classified as AML-M4 (patient 1) and AML-MO (patient 2). The coexistence of the two distinct neoplasms (AML and SM) was demonstrable by immunostaining of serial bone marrow (BM) sections with monoclonal antibodies (mAb). In particular, the MC infiltrates were found to react with mAb against MC-tryptase and MC growth factor receptor c-kit (CD117), but not with mAb to CD15 or CD34. In contrast, the AML blasts were immunoreactive for CD15 (patient 1) or CD34 (patient 2), but did not express tryptase. The c-kit point mutation Asp-->Val at codon 816, considered to play a role in the transformation of MC progenitors, was detected in patient 1 in a BM cell fraction containing 4% MC. However, no c-kit mutation was found in pure AML blasts (<1% MC). These findings argue against an evolution of the AML clone from neoplastic MC or MC-committed progenitors.
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PMID:Systemic mastocytosis associated with acute myeloid leukaemia: report of two cases and detection of the c-kit mutation Asp-816 to Val. 985 25

Some widely used antidepressants such as imipramine, clomipramine, and citalopram have been found to possess antineoplastic effects. In the present study, these compounds were found to induce apoptotic cell death in human acute myeloid leukemia HL-60 cells. Apoptosis induced by the antidepressants was identified by electron microscopy and conventional agarose gel electrophoresis and was quantitated by propodium iodide staining and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) via flow cytometry. Treatment with apoptosis-inducing concentrations of the antidepressants (80 microM imipramine, 35 microM clomipramine, or 220 microM citalopram) caused induction of caspase-3/caspase-3-like activity, which was monitored by the cleavage of poly(ADP-ribose) polymerase (PARP), the loss of the 32 kD caspase-3 (CPP32) precursor, and the cleavage of the fluorescent CPP32-like substrate PhiPhiLux. Pretreatment with a potent caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl-ketone (zVAD-fmk) inhibited antidepressant-induced CPP32/CPP32-like activity and apoptosis. Furthermore, activation of caspase induced by the antidepressants was preceded by the hypergeneration of intracellular reactive oxygen species (ROS). These results suggested that the antidepressants may induce apoptosis via a caspase-3-dependent pathway, and induction of apoptosis by the antidepressants may provide a clue for the mechanism of their antineoplastic effects.
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PMID:The antidepressants imipramine, clomipramine, and citalopram induce apoptosis in human acute myeloid leukemia HL-60 cells via caspase-3 activation. 1048 22

HePTP is a tyrosine specific protein phosphatase that is strongly expressed in activated T-cells. It was recently demonstrated that in transfected T-cells HePTP impairs TCR-mediated activation of the MAP-kinase family members ERK2 and p38 and it was suggested that both ERK and p38 MAP-kinases are substrates of HePTP. The HePTP gene has been mapped to human chromosome 1q32.1. Abnormalities in this region are frequently found in various hematopoietic malignancies. HePTP is highly expressed in acute myeloid leukemia and its expression in fibroblasts resulted in transformation. To address a possible involvement of HePTP in hematopoietic malignancies we sought to identify HePTP substrate(s) in leukemic cells. Using substrate trapping mutants we have identified the MAP-kinase ERK2 as a specific target of HePTP in the myelogenous leukemia cell line K562. Tyrosine phosphorylated ERK2, but not ERK1, p38, or JNK1, efficiently bound to catalytically inactive HePTP mutants in which the active site cysteine (HePTP-C/S) or the conserved aspartic acid residue (HePTP-D/A) had been exchanged for serine and alanine, respectively. Moreover, the interaction of ERK2 with HePTP trapping mutants was dependent on ERK2 tyrosine phosphorylation, indicating that HePTP is specifically targeted to activated ERK2. Using a deletion mutant of HePTP (HePTP-dLD), in which 14 amino acid residues within the N-terminus are missing, we show that regions outside the catalytic domain are also required for the interaction. Furthermore, overexpression of HePTP in K562 cells and fibroblasts interfered with PMA or growth factor induced MAP-kinase activation and HePTP efficiently dephosphorylated active ERK2 on the tyrosine residue in the activation loop in vitro. Together, these data identify ERK2 as a specific and direct target of HePTP and are consistent with a model in which HePTP negatively regulates ERK2 activity as part of a feedback mechanism. Oncogene (2000) 19, 858 - 869.
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PMID:The MAP-kinase ERK2 is a specific substrate of the protein tyrosine phosphatase HePTP. 1070 94

Activating mutations of c-kit at codon 816 (Asp(816)) have been implicated in a variety of malignancies, including acute myeloid leukemia (AML). The mutant c-Kit receptor confers cytokine-independent survival of leukemia cells and induces tumorigenicity. Changes in the signal transduction pathways responsible for Asp(816) mutant c-Kit-mediated biologic effects are largely undefined. The results of this study show that Asp(816) mutant c-Kit induces constitutive activation of signal transducer and activator of transcription 3 (STAT3) and STAT1, and up-regulates STAT3 downstream targets, Bcl-x(L) and c-myc. The phosphatidylinositol-3-kinase (PI-3K)/Akt pathway, but not the Ras-mediated mitogen-activated protein (MAP) kinase pathway, is also constitutively activated by Asp(816) mutant c-Kit. Suppression of STAT3 activation by a dominant negative molecule in MO7e leukemia cells transduced with mutant c-kit inhibits stem cell factor (SCF)-independent survival and proliferation, accompanied by the down-regulation of Bcl-x(L) and c-myc. However, activated STAT3 does not appear to be the sole mediator that is responsible for the phenotypic changes induced by Asp(816) mutant c-Kit, because expression of constitutively activated STAT3 in MO7e cells does not completely reconstitute cytokine independence. Activation of other signaling components by mutant c-Kit, such as those in the PI-3K/Akt pathway, is demonstrated and may also be needed for the mutant c-Kit-mediated biologic effects. The investigation of altered signal transduction pathways and the resulting functional consequences mediated by Asp(816) mutant c-Kit should provide important information for the characterization of subsets of leukemia and potential molecular pathways for therapeutic targeting. (Blood. 2001;97:3559-3567)
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PMID:Signal transducer and activator of transcription 3 activation is required for Asp(816) mutant c-Kit-mediated cytokine-independent survival and proliferation in human leukemia cells. 1136 51


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