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)

We conducted a Phase I-II trial of 4-demethoxydaunorubicin (idarubicin, IDR) in combination with 1-beta-D-arabinofuranosylcytosine (ara-C) in 51 patients with relapsed or refractory acute nonlymphocytic leukemia, acute lymphocytic leukemia, or chronic myelogenous leukemia in blast crisis. Only 1 of 12 patients treated at the first dose level (idarubicin, 10 mg/m2/day for 3 days and ara-C, 25 mg/m2 i.v. bolus followed by 200 mg/m2 continuous infusion daily for 5 days) achieved aplasia and complete remission. The dose of idarubicin was subsequently increased to 10 mg/m2/day for 4 days with the ara-C dose held constant. Complete remission incidence for this dose schedule was: 7 of 31 patients with acute nonlymphocytic leukemia, 0 of 5 patients with acute lymphocytic leukemia, 0 of 1 patient with chronic myelogenous leukemia in blast crisis, and 1 of 2 patients with biphenotypic leukemia. Nonhematological toxicity included nausea, vomiting, mucositis, and abnormal liver function tests. Detailed pharmacological studies were performed to determine whether ara-C altered IDR metabolism or that of its main metabolite, 13-hydroxyidarubicinol or IDR clearance. A high degree of variability among patients was apparent and no consistent effect could be demonstrated. In summary, 9 of 37 patients (24%) with relapsed or refractory ANLL, including 1 patient with biphenotypic leukemia, achieved remission. We conclude that idarubicin in combination with ara-C is an active combination in patients with relapsed or refractory leukemia.
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PMID:4-demethoxydaunorubicin (idarubicin) in combination with 1-beta-D-arabinofuranosylcytosine in the treatment of relapsed or refractory acute leukemia. 291 Apr 65

Two patients with acute nonlymphocytic leukemia (ANLL) developed peripheral motor and sensory neuropathies after consolidation chemotherapy with high-dose cytosine arabinoside (ara-C), daunorubicin, and asparaginase. Evidence for ara-C and daunorubicin-induced peripheral neuropathies is reported. Despite the frequent use of these agents, only two cases of peripheral neuropathy after systemic therapy have been previously described; neurotoxic effects may be potentiated and become clinically important when the three drugs are used in combination.
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PMID:Peripheral neuropathy after high-dose cytosine arabinoside, daunorubicin, and asparaginase consolidation for acute nonlymphocytic leukemia. 300 Dec 34

In this study, it has been shown that in 21 patients with AML the dCyd kinase and dCyd deaminase activities correspond closely to the clinical response to ara-C remission induction therapy. Patients with primary disease were treated with a conventional-dose ara-C regimen whereas nonresponders and relapsed patients followed an ID ara-C regimen (1 g/m2 X 12). Of these 21 patients (11 with primary disease and ten relapsed), seven had ara-C resistant disease (three primary and four relapsed patients). Five of the seven patients had a very low dCyd kinase and normal dCyd deaminase activity, whereas the other two had a normal dCyd kinase and an increased dCyd deaminase activity.
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PMID:Deoxycytidine kinase and deoxycytidine deaminase values correspond closely to clinical response to cytosine arabinoside remission induction therapy in patients with acute myelogenous leukemia. 303 20

The mechanisms of action of MTX and 5-FU have been further elucidated. Such studies will be important for the design of drug combinations and for the development of novel antifolate and fluoropyrimidine analogs. A greater understanding of MTX and ara-C transport and drug levels required to optimize transport may also aid in these endeavors. Pharmacokinetic parameters have been found to be predictors of relapse in children with acute leukemia, particularly with respect to MTX, 6-MP and ara-C. The intracellular terminal half-life of ara-C was correlated with remission duration in AML. Assay systems aimed at uncovering response predictors through biochemical analysis of patient tumor samples are being developed, including an interesting use of NMR spectroscopy to study the pharmacokinetics of fluorine-19-labeled 5-FU in vivo. Such an approach may yield valuable information on 5-FU anabolism in tumors in situ. A high frequency of resistance to MTX apparently may be generated within a single cell cycle by transient exposures to DNA synthesis inhibitors. The resistance may be based on either target enzyme amplification or altered membrane transport. These important studies provided bases for the rapid emergence of clinical resistance. Further, the multidrug-resistant phenotype appears to be a much broader based phenomenon as MTX resistance was found to be a frequent event in cells selected for multidrug resistance. A variety of novel approaches have been proposed to overcome antimetabolite resistance and to improve the selectivity of these agents, including the use of guanosine nucleotides, leucovorin and allopurines as biochemical modulators of 5-FU. Efficient techniques for the transfection of resistant DHFR into tissues using retroviruses have been reported. These studies serve as starting point for the ultimate development of more effective strategies for the treatment of human malignancies.
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PMID:Antimetabolites. 307 79

The accumulation of cytosine arabinoside-5'-triphosphate (ara-CTP), the activities of nucleotide-metabolizing enzymes and the nucleoside transport capacity were examined in eleven human leukemic cell lines differing in phenotype. The highest amount of ara-CTP was accumulated in T-acute lymphoblastic leukemia cells (T-ALL), followed by myeloid leukemia cell lines (AML), and the least accumulation was observed in common acute lymphoblastic leukemia (c-ALL) and B-acute lymphoblastic leukemia cells (B-ALL). The levels of enzymes involved in ara-C metabolism (deoxycytidine kinase, pyrimidine monophosphate kinase and deoxycytidylate deaminase) did not correlate with ara-CTP accumulation. The sensitivity of the leukemic cell lines to ara-C, which was measured in terms of decrease of clonogenic survival, correlated with the amount of ara-CTP formed. Moreover, the nucleoside transport capacity, estimated from the binding of the radiolabeled nucleoside analogue, [3H]nitrobenzylthioinosine, showed a good correlation with ara-CTP accumulation. The mean numbers of nucleoside-binding sites in T-ALL cells were significantly greater than in B-ALL cells. We conclude that the cellular nucleoside transport capacity is the most important factor for the formation and accumulation of ara-CTP in the cells.
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PMID:Formation of cytosine arabinoside-5'-triphosphate in cultured human leukemic cell lines correlates with nucleoside transport capacity. 311 33

Dose-related effects of ara-C include overcoming a relative transport impediment in human leukemia cells. This result then allows intracellular metabolism and incorporation into DNA to proceed to the maximum extent possible. In addition, the increased synthesis of ara-CDP-choline associated with these high doses may serve as an alternate substrate for phosphatidyl choline synthesis, which may contribute to membrane fragility and cell lysis. HiDAC also serves as a "prodrug" for high concentrations of ara-U, which in turn diminishes ara-C catabolism with a prolonged gamma phase of systemic clearance and also causes cytostasis in S-phase with enhanced anabolism and cytotoxicity of subsequent doses of ara-C. This metabolite/drug interaction could be termed "self-potentiation," a feature which contributes to the overall activity of HiDAC. Asparaginase enhances these effects in a schedule-dependent fashion by lowering the cellular pool size of dCTP and consequent enhanced metabolism of ara-C. The therapeutic benefit of these pharmacologic manipulations has been verified in a randomized clinical trial in patients with acute myelogenous leukemia.
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PMID:The pharmacologic basis for the efficacy of high-dose Ara-C and sequential asparaginase in adult acute myelogenous leukemia. 316 12

In an attempt to identify pharmacokinetic factors that determine the response of acute myeloid leukemia (AML) patients to induction chemotherapy, we determined the concentrations of daunorubicin (DNR) and the main metabolite daunorubicinol (DOL) in vivo and particularly evaluated the concentrations in blood and bone marrow nucleated cells. Cell measurements were obtained in 37 evaluable patients during their first remission induction treatment with DNR and cytarabine (ara-C) and directly compared with the plasma distribution kinetics of DNR. We show that (1) plasma DNR concentrations do not correlate with DNR concentrations in bone marrow nucleated cells; but (2) plasma area under the curve (AUC) values of DNR correlate inversely (P less than .01) with AUC values of DNR in WBCs; (3) concentrations of DNR in WBCs correlate positively (P less than .01) with DNR concentrations in bone marrow nucleated cells; and (4) the concentrations of DNR in WBCs show a negative correlation (P less than .01) with the numbers of peripheral blast cells at diagnosis. We then tested whether the pharmacokinetic parameters had predictive value for the clinical outcome of therapy, but none of the plasma levels or WBC and bone marrow concentrations of DNR predicted treatment outcome. The inverse correlation between the concentrations of DNR in WBC and the numbers of peripheral blast cells suggests that the effective DNR concentrations achieved intracellularly are mainly a function of the tumor load so that lesser amounts of DNR accumulate intracellularly when the AML cell numbers in blood are higher.
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PMID:Cellular pharmacokinetics of daunorubicin: relationships with the response to treatment in patients with acute myeloid leukemia. 316 63

Morphological-identified blast populations are the hallmark of the malignant clones that dominate hemopoiesis in acute myeloblastic leukemia (AML). Marked heterogenity is characteristic of AML blasts. Patient-to-patient variation is seen in their biological properties but is particularly evident in the response to treatment. Intraclonal variation is generated during clonal expansion, particularly as blast stem cells either undergo self-renewal or enter into a series of terminal divisions. These two alternative activities can be monitored in cell culture using a clonogenic assay and a suspension assay. The balance between renewal and differentiation can be altered by exposing blast populations to various growth factors in culture. Further, certain drugs, particularly ara-C, appear to be more toxic for self-renewing divisions than cell-cycle events generally. We suggest that both drugs and growth factors should be assessed for their effects on self-renewal as part of preclinical testing.
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PMID:Heterogeneity in acute myeloblastic leukemia. 319 79

The evolution of in vitro bone marrow clonogenic leukaemic cells (CFU-L) drug sensitivity was studied in 23 patients with acute myeloid leukaemia treated with anthracycline and cytosine arbinoside (ara-C). In 12 patients tested before and after first induction treatment failure (interval: 6 +/- 4 weeks), the sensitivity remained stable for daunorubicin and showed little variation for ara-C. Among eleven patients tested before treatment and at first relapse (interval: 13 +/- 7 months), in vitro CFU-L sensitivity revealed no correlation between the two measurements, and a trend in decreased sensitivity to daunorubicin and ara-C. These findings suggest that induction failures could be related to factors other than simple selection of a resistant CFU-L subclone.
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PMID:In vitro sensitivity of clonogenic cells in resisting and relapsing patients with acute myelogenous leukaemia. 321 66

We have evaluated the possibility of enhancing the cell killing effect of ara-C on AML blasts by increasing their proliferative activity with haemopoietic growth factors. Leukaemic cells from 10 AML patients were incubated for 3 d in liquid culture in the presence or in the absence of the human recombinant growth factors IL-1 beta (5 U/ml) and IL-3 (3 U/ml), and subsequently exposed to ara-C (3 micrograms/ml) for the last 24 h. The number of residual leukaemic stem cells was evaluated by a clonogenic assay in semisolid medium. The results showed that ara-C exposure inhibits the proliferation of a higher proportion of clonogenic cells in cultures pretreated with growth factors than in the controls (mean inhibitory values: in the absence of growth factors = 49.8%; with IL-1 beta = 58.3%; with IL-3 78.9%). The effect was statistically significant only when IL-3 was used as a growth factor. The results suggest that haemopoietic growth factors may help to improve the therapeutic index of cytostatic agents.
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PMID:Interleukin 3 enhances the cytotoxic activity of 1-beta-D-arabinofuranosylcytosine (ara-C) on acute myeloblastic leukaemia (AML) cells. 326 44


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