Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.1 (asparaginase)
 2,695 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Limulus amebocyte lysate assay was used to detect the presence of bacterial endotoxin in a variety of chemotherapeutic agents currently in use. Results were quantitated using a standard Escherichia coli endotoxin curve. Relative concentrations of endotoxin ranging from 0.1 to 63 ng/ml were detected in individual lots of L-asparaginase, 5-azacytidine, bleomycin, DTIC, actinomycin D, adriamycin, and vinblastine diluted to normal concentrations for injection. When multiple lots of a given drug were tested, at least one lot produced a negative assay, indicating less than 0.1 ng/ml of endotoxin in 50% of these drugs. All lots of cytosine arabinoside, cyclophosphamide, daunorubicin, vincristine, and streptozotocin tested had less than 0.1 ng/ml of endotoxin. Inactivation kinetics of the Limulus-positive drug material in dilute alkali solutions were identical to those of E. coli endotoxin. The Limulus lysate test is a rapid and specific method for the detection of small amounts of bacterial endotoxin contaminating parenteral preparations of antitumor agents.
Cancer Treat Rep 1976 Jan
PMID:Detection of bacterial endotoxin in antitumor agents. 79 13

The effect of pretreatment with L-asparaginase on the cytotoxicity of methotrexate (MTX) was studied in L5178Y murine leukemic cells and L-929 cells grown in vitro. The results were correlated with the effects of L-asparaginase on DNA synthesis. At low concentrations of the enzyme, pretreatment of cells enhanced the effect of MTX; at higher concentrations, it prevented the effect of MTX. Elimination of the MTX action was demonstrated also in L5178Y cells growing in the medium lacking L-asparagine. L-Asparagine readdition resulted in enhancement of MTX cytotoxicity. Pulse-labeling experiments demonstrated that in every case elimination of MTX action was related to a diminution of the fraction of cells in the phase of DNA synthesis. In contrast, enhancement of the effect of MTX was related to an increase in the fraction of cells in the DNA synthesis phase. A similar parallelism of effects occurred in L-929 cells when pretreatment with L-asparaginase was followed by washing the cells and culturing them in medium without the enzyme.
Cancer Res 1975 Jun
PMID:Role of amino acid depletion in combined treatment of neoplastic cells with methotrexate and L-asparaginase. 80 60

An undifferentiated human pancreatic carcinoma has been established in continuous culture and is grown in Dulbecco's modified. Eagle's medium fortified with 10% fetal calf serum and 2.5% horse serum. The established cell line (MIA PaCa-2) has a doubling time of 40 h. The cells are large with abundant cytoplasm, exhibit a high degree of aneuploidy and have a tendency to grow on top of other cells. MIA PaCa-2 grows in soft agar with a colony-forming efficiency of 19%. Both MIA PaCa-2 cells and a cell line from another pancreatic carcinoma obtained from National Cancer Institute (NCI) are sensitive to asparaginase, a property not shared by several other human tumor cell lines tested.
Int J Cancer 1977 Jan
PMID:Human pancreatic carcinoma (MIA PaCa-2) in continuous culture: sensitivity to asparaginase. 83 18

This paper is concerned with the evaluation of the in vivo performance characteristics of reconstituted bovine collagen as an insoluble carrier matrix fro therapeutic enzymes. The enzyme that was chosen as a model for this evaluation was E. coli L-asparaginase, which has been widely investigated as a soluble chemotherapeutic agent for the treatment of acute lymphocytic leukemia in humans (Oettgen et al., Cancer Res., 27, 2619, 1967 ; Beard et al., Brit. Med. J., 1, 191, 1970; Ohmuma et al., Cancer Res., 30, 2297, 1970). The results presented here were obtained from perfusion trials with a collagen-asparaginase reactor incorporated into an extracorporeal circuit attached to the vascular systems of healthy mongrel dogs. A series of 1-2 hr perfusions were conducted with a single collagen-asparaginase membrane over a period of 4 months. Serum asparagine levels were reduced by more than 98% after 15-30 min perfusion time. Red blood cell (RBC), hemoglobin, hematocrit, and fibrinogen values remained constant during each perfusion. An average decrease of 48% in white blood cell (WBC) and 24% in platelet levels was observed, but these values began to rise slowly even before cessation of the perfusion. No serious toxic or antigenic reactions or mechanical or clotting difficulties were observed. In vitro activity, when assayed between perfusions, remained constant over a period of 4 months of intermittent use and storage. The potential advantages of collagen-enzyme complexes for the administration of therapeutic enzymes is discussed.
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PMID:Perfusion trials with a collagen-immobilized enzyme in an extracorporeal reactor: activity, stability, and biocompatibility. 84 82

After nitrosoguanidine mutagenesis we isolated from mouse leukemia L5178Y cells a mutant cell (Bla-R) resistant to blasticidin S, an inhibitor of protein synthesis. Neither growth nor leucine incorporation into hot-acid insoluble fraction of Bla-R cell was inhibited by 5 to 20 microgram/ml blasticidin S, which almost completely blocked protein synthesis as well as growth of the parental L5178Y cells. However, other inhibitors such as fusidic acid, cycloheximide, ricin D or L-asparaginase blocked protein synthesis in Bla-R cells to the same extent as in L5178Y cells. Protein synthesis in vitro using S-30 extracts from the parental cell line L5178Y was almost completely blocked in the presence of the antibiotic, while no inhibition by blasticidin S occurred when S-30 extracts -rom Bla-R mutant cells were used. Protein synthesis assays were made by using the S100 fraction from rat liver together with ribosomes from either L5178Y cells or Bla-R cells. Blasticidin S inhibited protein synthesis when ribosomes were derived from L5178Y cells, but not from Bla-R mutant.
Int J Cancer 1977 Aug 15
PMID:A mouse leukemia cell mutant resistant to blasticidin S. 89 36

Twenty-one children with acute nonlymphoblastic leukemia (ANLL) were treated with a combination regimen consisting of arabinosyl cytosine (Ara-C), 6-thioguanine (TG), and Adriamycin, The incidence of complete remission was 74%. For consolidation, addition courses of Ara-C and TG were given, followed by L-asparaginase. The maintenance program was the same as that for the lymphoblastic type (L-2) including intrathecal methotrexate for prophylaxis of meningeal leukemia. Of the 16 who were evaluable for the duration of complete remission, six developed bone marrow relapse, one meningeal leukemia within 3-14 months after entering complete remission and one was lost to follow-up. Eight remain in complete remission for 9-72 months. In five of eight, chemotherapy has been terminated after 3 years, and all continue in remission for 11-32 months post-treatment. Although the results do not compare well to those of the lymphoblastic morphology, long-term disease-free survival can be achieved with multiple-drug intensive treatment in childhood ANLL.
Cancer 1977 Oct
PMID:Treatment of acute nonlymphoblastic leukemia in children with a multiple-drug protocol. 90 61

We analyzed the effect of asparagine starvation and L-asparaginase on RNA metabolism of mouse leukemia cell lines L5178Y, whose growth is dependent on the presence of asparagine, and L5178Y-R, whose growth is independent of the presence of asparagine. The deprivation of asparagine from the medium inhibited cellular protein synthesis by 30 to 40% of the control value in L5178Y cells, but not in L5178Y-R cells, whereas L-asparaginase inhibited synthesis by more than 80% in both L5178Y and L5178Y-R cells. The decrease in protein synthesis caused by asparagine starvation in L5178Y cells was accompanied by a decrease in ribosomal RNA synthesis. The synthesis of rRNA was also markedly blocked when L5178Y and L5178Y-R cells were exposed to L-asparaginase. The rate of synthesis of pulse-labeled RNA decreased significantly in the cells treated with L-asparaginase, and smaller pieces of polyadenylate containing pulse-labeled RNA (presumptive messenger RNA) appeared among monosomes and polysomes. However, the rate of messenger RNA synthesis was constant during asparagine starvation, and a marked accumulation of monosome was observed.
Cancer Res 1976 Oct
PMID:Effect of l-asparaginase and asparagine deprivation on RNA metabolism in mouse leukemia L 5178Y cells in suspension culture. 98 38

At least two chemotherapeutic agents, prednisone and L-asparaginase, have been demonstrated to produce pancreatic injury. Early diagnosis of pancreatitis is frequently not possible, as symptoms are vague, physical findings may be minimal, and laboratory studies are frequently inconclusive until the injury is severe. Abdominal echography, as a monitor of pancreatic size, has proven to be helpful in the diagnosis of subclinical and early pancreatic injury of 14 of 19 selected children receiving prednisone and/or L-asparaginase therapy for acute leukemia or non-Hodgkin's lymphoma at the M.D. Anderson Hospital and Tumor Institute. Employment of this new diagnostic method permits prompt withdrawal of the causative agent(s), thus preventing further insult.
Cancer 1976 Oct
PMID:Early detection of chemotherapy-related pancreatic enlargement in children using abdominal sonography: a preliminary report. 99 Oct 74

Cytosine arabinoside (CA) was utilized in efforts to synchronize leukemic cells in DNA synthesis for treatment with vincristine, prednisone, and L-asparaginase in children with acute leukemia in relapse. The results did not indicate any therapeutic advantage for patients treated with this combination compared to those treated without any attempt at CA synchronization.
Cancer Treat Rep 1976 May
PMID:Study of cytosine arabinoside (NSC-63878) synchronization plus vincristine (NSC-67574), prednisone (NSC-10023), and L-asparaginase (NSC-109229) for remission induction in advanced acute leukemia in children. 99 Nov 48

A method potentially capable of enhancing the effectiveness of therapeutic enzymes such as L-asparaginase was investigated. The method was suggested by the following properties that have been observed for lectins injected into tissues: (1) six lectins with differing specificities were retained near the site of injection in the feet of mice 10 to 100 times longer than several non-lectin proteins. Prolonged retention of 125I-labelled concanavalin A was also observed in other normal and malignant mouse tissues. (2) The retention of 125I-labelled concanavalin A was not affected by prior immunization against concanavalin A. (3) Electrophoresis of tissue extracts on sodium dodecyl sulfate-poly-acrylamide gels followed by radioautography indicated that the 125I-labelled concanavalin A retained in the tissue remained as intact in form as prior to injection. Since the therapeutic efficacy of many enzymes may be enhanced by localization at the intended site of action, in principle it should be possible to enhance the effectiveness of therapeutic enzymes by combining the tissue-localizing properties of a lectin with therapeutic effectiveness of the enzyme. A conjugate of E. coli L-asparaginase and concanavalin A has been prepared by covalent cross-linking with glutaraldehyde and has been shown to be retained in mouse tissue 90 times longer than the free enzyme. However, it is completely ineffective in the treatment of the L-asparaginase-sensitive lymphosarcoma 6C3HED in C3H/HeJ mice. The ineffectiveness of the conjugated enzyme may be associated with the interiorization of the conjugate by the cells of the tumor.
Int J Cancer 1976 Nov 15
PMID:Effect of localization of L-asparaginase as the concanavalin A conjugate on anti-tumor activity. 103 89


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