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

The human glioma-derived cell line D-54 MG and the human medulloblastoma-derived cell line TE-671 have been shown to be sensitive in culture to the pharmacological interference with glutamine metabolism by acivicin, 6-diazo-5-oxo-L-norleucine, and methionine sulfoximine. Using as a guide the multiple contributions of glutamine to the biosynthesis of proteins, purines, and pyrimidines, we now have identified six additional antimetabolites active against these lines in vitro at clinically relevant concentrations. The 50% growth-inhibitory levels of the drugs against D-54 MG in 6-day continuous exposure experiments were: L-asparaginase, 0.057 IU/ml; 5-fluorouracil, 0.5 micrograms/ml; 6-mercaptopurine, 0.8 micrograms/ml; actinomycin D, 0.0007 micrograms/ml; N-phosphonacetyl-L-aspartic acid, 2.3 micrograms/ml; and 5-azacytidine, 0.2 micrograms/ml (3-day exposure. The corresponding 50% growth-inhibitory values in TE-671 were: L-asparaginase, 0.54 IU/ml; 5-fluorouracil, 1.5 micrograms/ml; 6-mercaptopurine, 4.7 micrograms/ml; actinomycin D, 0.00044 micrograms/ml; N-phosphonacetyl-L-aspartic acid, 4.5 micrograms/ml; and 5-azacytidine, 0.49 micrograms/ml. Dipyridamole up to 10 micrograms/ml was inactive against both lines. The isobologram method was used to evaluate the effectiveness of several two-drug combinations which were biochemically designed. The sums of the optimal fractional inhibitory concentrations for the pairs were: acivicin plus L-asparaginase, 0.14; acivicin plus methionine sulfoximine, 0.40; 6-diazo-5-oxo-L-norleucine plus methionine sulfoximine, 0.60; acivicin plus 6-mercaptopurine, 1.0, all in TE-671; and acivicin plus 5-fluorouracil, 0.79, in D-54 MG. Our findings suggest that an antimetabolite regimen exploiting glutamine sensitivity might improve the chemotherapy of some human gliomas and medulloblastomas.
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PMID:Combination chemotherapy in vitro exploiting glutamine metabolism of human glioma and medulloblastoma. 402

In 86 children with acute lymphocytic leukemia (ALL) and in 6 children with medulloblastoma 253 24-hour methotrexate (MTX) infusions with 150, 500, and 700 mg/m2 were performed. MTX concentrations in plasma and cerebrospinal fluid (CSF) were measured with a specific radioimmunoassay. In 131 infusions with 500 mg/m2 given to patients with ALL in remission, the MTX plasma concentration 24 h after the end of infusion did not exceed 7 X 10(-7) mol/1. Mild hematologic toxicity occurred in 22% of the treatment cycles. In contrast 8/45 infusions given to patients with ALL in relapse were associated with delayed MTX elimination followed by severe toxicity. The CSF: plasma ratio of MTX measured during 58 infusions did not exceed 11% in patients with ALL in remission, but was above this value in 13/34 infusions in patients with leukemia of the central nervous system (CNS). 24-hour MTX infusions with 500 mg/m2 were as hepatotoxic as 4- to 6-hour infusions with 3-8.5 g/m2. With MTX as single agent no remissions were achieved in 8 patients with ALL in relapse. The addition of asparaginase in 10 patients resulted in 3 complete and 2 partial remissions. In patients with ALL in first remission clinical results confirmed the value of intensive MTX therapy for disease-free survival.
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PMID:Prolonged methotrexate infusions in children with acute leukemia in relapse and in remission and with medulloblastoma. Pharmacokinetics, toxicity and clinical results. 658 60