Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1-beta-D-Arabinofuranosylcytosine (cytarabine; ara-C) and 5-azacytidine (5-azaCR), cytosine nucleoside antimetabolites with different mechanisms of action, are both effective in the treatment of human leukemia, and the clinical use of these two agents in combination has been suggested. We have studied the therapeutic effect in L1210 leukemic mice of single i.p. doses of ara-C and 5-azaCR in combination. Therapeutic effects observed depended markedly on the sequence and time interval between the doses of each agent. Antagonism was observed when both agents were administered simultaneously. The optimal therapeutic effect was observed when 5-azaCR was administered after ara-C at a time when tumor DNA synthesis had maximally recovered after the ara-C dose. The dose-interval effect and correlation with recovery of DNA synthesis capacity were also observed in studies in vitro in which the survival of L1210 cells in culture was examined. ara-C was shown to inhibit the incorporation of [4-14C]-5-azaCR-derived radioactivity into DNA of L1210 cells in culture, and the therapeutic effects observed are interpreted in terms of these latter results and the mechanisms of action of the two agents.
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PMID:Combination chemotherapy of L1210 leukemia with 1-beta-D-arabinofuranosylcytosine and 5-azacytidine. 5 29

The results of the administration of two antimetabolites, methotrexate (MTX) and cytosine arabinoside (Ara-C), for the prevention and treatment of established central nervous system (CNS) disease in children with acute lymphoblastic leukemia are discussed. Two protocols (L-2 and L-10) for the management of patients with acute lymphoblastic leukemia have been developed. In the L-2 protocol, prophylaxis consists of repeated intralumbar injections of MTX alone, and in the L-10 regimen, both MTX and Ara-C are administered; for the patients with an initial leukocyte count of greater than or equal to 25,000/mm3, the two drugs are given intraventricularly instead of by the usual intralumbar route. In the treatment of established CNS leukemia, intralumbar MTX and Ara-C in addition to CNS irradiation are employed; for maintenance, periodic intraventricular MTX injections are given. Of the 70 children receiving the L-2 protocol, four developed CNS leukemia and in a fifth patient, CNS and bone marrow relapse were concurrent. Among the 31 children receiving the L-10 regimen, CNS disease has been observed in only one child. Of the five children treated for the established CNS leukemia, recurrence was observed in two at 19 and 29 months after remission; the other three remain in remission for 2, 15, and 39 months, respectively.
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PMID:Antimetaboliths in the prophylaxis and treatment of central nervous system leukemia. 26 7

Leukaemia cells from the peripheral blood and bone marrow of patients with acute myeloblastic leukaemia were labelled in vitro with [125I]5-iodo-2'-deoxy-uridine (IUdR). The myeloblasts were then injected into groups of mice and the survival of these cells estimated by measuring isotope loss, using whole-body counting. The isotope excretion from mice treated with various doses of cytosine arabinoside (Ara-C) and those not treated with drugs were compared. This comparison showed that the sensitivity of myeloblasts to the drug varies from patient to patient, and in one case was different for myeloblasts from bone marrow and from blood from the same patient. We compare the clinical responses of myeloblasts to Ara-C in 6 patients, who had high peripheral blood myeloblast counts, with the sensitivities of their myeloblasts to Ara-C in mice. This comparison indicates that the assay might be a useful way of predicting the response of leukaemic cells in patients to cytotoxic agents.
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PMID:Assessment of drug sensitivity of human leukaemic myeloblasts. II. The toxic effects of cytosine arabinoside on 125IUdR-labelled human leukaemic myeloblasts in mice. 27 Mar 73

1-beta-D-Arabinofuranosylcytosine diphosphate choline was formed from 1-beta-D-arabinofuranosylcytosine (ara-C) during incubation in vitro of peripheral myeloblasts from patients with acute myelogenous leukemia and cultured cells (nonleukemic human lymphocytes, mouse lymphoma L5178Y, and HeLa); as well, 1-beta-D-arabinofuranosylcytosine diphosphate choline was formed in vivo in mouse leukemia L1210 cells and mouse liver. 3-Deazauridine enhanced the anabolism of ara-C in nonleukemic lymphocytes in vitro and leukemia L1210 cells in vivo but did not influence ara-C anabolism in the other cell types. In acute myelogenous leukemia myeloblasts incubated in vitro with ara-C, concentrations of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate were maximal after 8 hr of incubation and formation of the latter preceded that of 1-beta-D-arabinofuranosylcytosine diphosphate choline.
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PMID:Formation of 1-beta-D-arabinofuranosylcytosine diphosphate choline in neoplastic and normal cells. 27 75

Cytarabine and thioguanine therapy for acute myelomonocytic leukemia initiated in the tenth week of pregnancy (with the addition of vincristine and rubidomycin at 17 weeks) led to a short complete remission of the leukemia in a 24-year-old primigravida. This is the first case to be reported in which cytarabine was administered in the first trimester and a prostaglandin termination of pregnancy performed at 20 weeks produced an apparently normal fetus. A review of the literature suggests a slightly less than 50% chance of producing a live healthy baby if acute myelogenous leukemia is diagnosed in the first half of pregnancy, with materna mortality approaching 100% by six months postpartum. Current therapy may improve these figures.
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PMID:Consequences of acute myelogenous leukemia in early pregnancy. 33 24

Tumor cells were isolated from malignant effusions of three patients with disseminated solid tumors of different origin. Intracellular accumulation of nondiffusible cytosine arabinoside (ara-C) nucleotides was used to measure phosphorylation. Mouse leukemia L 1210 and L 1210/CA, and ara-C-resistant subline, were used as reference cells. Phosphorylation activity was similar in the cells from all three solid tumors and showed a linear increase with drug concentrations of 0.1--100 micograms/ml. In contrast to activity in L 1210 cells, the in vitro activity was not saturable at drug levels up to 100 micrograms/ml. Ara-C inhibited the incorporation of thymidine into DNA 84%--90% in the solid tumor cells at a concentration of 10 micrograms/ml. Higher drug concentrations did not result in further inhibition. In one patient, DNA synthesis of tumor cells isolated before and after intraperitoneal instillation of 1,000 mg ara-C was measured. The in vivo inhibition was found to correspond to the in vitro data. Solid tumor cells isolated from malignant effusion have no greatly reduced capacity for cellular formation of ara-C/nucleotides, but higher drug levels than achieved with conventional therapy are necessary for sufficient ara-C nucleotide synthesis.
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PMID:Action of cytosine arabinoside on human tumor cells isolated from malignant effusions: in vitro phosphorylation and inhibition of DNA synthesis. 48 20

Thirteen leukemic patients with disease refractory to conventional chemotherapy were treated with 1.0 to 7.5 g/m2 of Cytosine Arabinoside (Ara-C) over 29 drug cycles. Drug infusions were spaced at 12-hour intervals; a maximum of four doses was administered over 36 hours. After single dose tolerance had been established, three or four dose cycles were given at 2- to 30-day intervals. There were three partial remissions (PR) and one complete remission (CR) in a treatment group of four patients with AML, five with ALL, two with lymphoma converted to leukemic phase, one CML in blast crisis, and one promyelocytic leukemia. Five of the patients were septic and considered terminally ill at the time of treatment. All other patients had evidence of drug responsiveness. The nadir of the white count occurred from 3 to 12 days after treatment, with subsequent recovery of the peripheral granulocyte count between days 12 and 28. Toxicity included nausea and vomiting (GI symptoms) in twelve patients, central nervous system (CNS) disturbances in eight patients, one episode of inappropriate antidiuretic hormone syndromes (SIADH), one of hyperuricemia, and fever in eleven patients. There was no evidence of hepatic or renal dysfunction. These high doses of Ara-C appear useful for treatment of patients with refractory leukemia. Hospitalization is brief and toxicity acceptable.
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PMID:High dose cytosine arabinoside (HDARAC) in refractory acute leukemia. 49 9

The rational design of antitumor and antiviral agents must ultimately take advantage of biochemical differences between normal host cells and transformed cells. The initial experiments must be performed with subcellular or cellular model systems. For the studies with arabinosyl nucleosides we have chosen those enzyme systems, synthesizing DNA and RNA; being precursor analogues, the different arabinosyl nucleosides have been added in the triphosphate state to the different DNA- and RNA polymerase assays. 1-beta-D-Arabinofuranosylcytosine-5'-triphosphate has been found to inhibit the RNA-dependent DNA polymerases (isolated from oncogenic RNA viruses) 200-fold more sensitively than viral and cellular DNA-dependent DNA polymerases. Recent results, showing that RNA-leukemia-virus-related sequences are present in DNA of some human leukemia patients might support the assumption that the efficacy of this antimetabolite in the treatment of acute leukemia is due to its, at least relative selective inhibitory activity on reverse transcriptase. 9-beta-D-Arabinofuranosyladenine-5'-triphosphate is a strong inhibitor of cellular DNA polymerases with the cytological consequence of an inhibition of cell proliferation. The clinical benefit of the compound in treatment of tumors is dependent on their levels of adenosine deaminase. The triphosphate of this compound is a 100-fold more sensitive inhibitor of the herpesvirus DNA polymerase compared to the cellular replicative DNA polymerase. In addition the analogue, incorporated into herpesvirus DNA, acts as chain terminator. These effects are the biochemical basis for the highly selective antiherpesvirus activity of this antimetabolite. The anomer 9-alpha-D-arabinofuranosyladenine-5'-triphosphate only inhibits cellular replicative DNA polymerase and has no effect on herpesvirus DNA polymerase. Consequently this agent acts only cytostatically and not antivirally. Concerning 1-beta-D-arabinofuranosyluracil and 1-beta-D-arabinofuranosylthymine no pronounced antitumor or antiviral effect is known.
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PMID:Rational design of arabinosyl nucleosides as antitumor and antiviral agents. 61 2

Except for oral administration, there was no grossly observed toxicity from carefully administered high doses of amygdalin in the experimental systems used. The compound in high doses was ineffective against the DMBA-induced rat mammary carcinoma and the following transplanted experimental tumors: Sarcoma 180, plasma cell tumor LPC-1, leukemia L1210, Mecca lymphosarcoma, Ridgway osteogenic sarcoma, sarcoma T241, mammary carcinoma E0771, Taper liver tumor, Ehrlich carcinoma (solid and ascites), and Walker carcinosarcoma 256. Amygdalin did not noticeably influence the toxicity or impair the efficacy of these chemotherapeutic agents in their respective systems: Cytosine arabinoside, methotrexate, cytoxan, or 5-fluorouracil in L1210; the latter two in LPC-1; 6-mercaptopurine in Ridgway osteogenic sarcoma; estradiol-17beta or 2alpha-methyldihydrotestosterone propionate in the DMBA-induced rat mammary carcinoma.
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PMID:Antitumor tests of amygdalin in transplantable animal tumor systems. 64 16

In two patients with acute leukaemia, the development of progressive interstitial pulmonary fibrosis was observed following chemotherapy with BCNU, Cytoxan and Ara-C. The x-ray changes were accompanied by restrictive changes of pulmonary function and, later on, by severe hypoxia. Serologic tests did not reveal infection with cytomegaly virus or mycoplasma pneumoniae. These findings, together with reports in the literature, suggest a toxic effect of BCNU on the lung. The combination with Cyclophosphamide may contribute to this toxic reaction.
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PMID:[Progressive pulmonary fibrosis during combination chemotherapy with BCNU (author's transl)]. 65 38


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