Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During a 4-year period, 26 children with systemic malignancies suffered cerebrovascular accidents. These occurred in 17 patients with lymphoreticular malignancy and nine patients with solid tumors. They were the presenting signs of malignancy in three patients and were the direct cause of death in six. Cerebrovascular accidents were directly related to disseminated intravascular coagulation in eight patients, to chemotherapy in eight patients, to metastatic tumor in three patients, to thrombocytopenia in three patients, and to fungal meningitis in one patient. All patients with disseminated intravascular coagulation had leukemia and at times, cerebrovascular thrombosis predated systemic or laboratory evidence of disseminated intravascular coagulation. This review indicates that four major syndromes are apparent in children with cancer: vascular thrombosis associated with disseminated intravascular coagulation, acute arterial or sagittal sinus thrombosis secondary to L-asparaginase in children with leukemia, acute neurologic dysfunction in patients with osteogenic sarcoma treated with high-dose methotrexate, and obtundation, seizures, and focal neurologic deficits in patients with neuroblastoma metastatic to the torcular region. Although elevated WBC counts and thrombocytopenia occur frequently in children with cancer, in themselves they uncommonly result in strokes. It is concluded that cerebrovascular accidents are a relatively frequent cause of acute neurologic compromise in children with cancer and that certain types of malignancies and their treatment predispose patients to this complication.
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PMID:Cerebrovascular accidents in children with cancer. 386 Jul 96

Previous work suggested a relationship between glycine metabolism and the effect of L-asparaginase upon tumor cells. Therefore, L5178Y (sensitive) or L5178Y/L-ASE (resistant) ascites lymphoma cells were incubated with 14C-labeled glyoxylate, glycine, serine, or asparagine, and the metabolism to other amino acids was measured by high performance liquid chromatography. Metabolic differences between the two cells lines were found. Under control conditions, the interconversion rate of glycine and serine via serine hydroxymethyltransferase (SHMT) was higher in sensitive than in resistant cells. The transformation rate of glyoxylate to serine was also higher in sensitive cells. These results may indicate a difference in the activity of SHMT. An alternate explanation would be that transport or diffusion of serine and glycine into sensitive cells is greater than into resistant cells. Several crucial metabolic differences were observed between the two cell types when L-asparaginase was added. A key difference is the decrease of glycine synthesis from glyoxylate observed in the sensitive cells compared to resistant cells which show no change. This suggests that asparagine is used for transamination of glyoxylate. Also, only sensitive cells appear to compensate for L-asparaginase-induced loss of glycine formation from glyoxylate by increasing glycine synthesis from serine. Alterations in sensitive tumor glycine metabolism may be an important function of L-asparaginase anticancer activity.
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PMID:Comparison of glycine metabolism in mouse lymphoma cells either sensitive or resistant to L-asparaginase. 391 41

Forty-eight tumor-free mice and 32 mice bearing Ehrlich ascites tumor were randomized into 2 treatments, Acinetobacter glutaminase-asparaginase (AGA) (600 IU/kg/day for 7 days) and 0.9% NaCl controls, and into 2 or 3 isocaloric diets, normal protein (NP) (20 g protein/100 g diet), high protein (HP) (58 g protein/100 g diet), and zero protein (ZP) (tumor-free mice only). In tumor-free, NP-fed mice, AGA caused percentage reductions (P less than 0.01) in the nitrogen content of liver (50%), intestine (42%), thymus (89%), spleen (75%), and carcass (20%), but HP prevented this effect on intestine and carcass and caused percentage increases in the nitrogen content of liver (53%), intestine (36%), thymus (122%), and carcass (25%). In Ehrlich ascites tumor mice (NP or HP fed) AGA caused markedly lower (P less than 0.01) tumor burdens and increased nitrogen content of intestine (HP), kidney (NP and HP), and spleen (NP and HP). Ehrlich ascites tumor, AGA-treated, HP-fed mice ate 31% less food (P less than 0.01) (compared to NP) but HP resulted in percentage increases in the nitrogen content of liver (18%; P = 0.05), intestine (25%; P less than 0.05), and thymus (164%; P less than 0.01). In the Ehrlich ascites tumor, AGA group the HP diet caused higher hematocrit and serum total protein (both, P less than 0.05). Adverse nutritional effects of AGA seen in normal mice were markedly diminished in tumor-bearing animals. The observed nitrogen-sparing effects of the high protein: energy ratio may be relevant to humans and to other forms of neoplasia and chemotherapy.
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PMID:Tissue nitrogen-sparing effect of high protein diet in mice with or without ascites tumor treated with Acinetobacter glutaminase-asparaginase. 402 74

The amino acid contents of tumor cells that are either sensitive or resistant to treatment with L-asparaginase were measured. These amino acid concentrations were measured as a function of incubation time with L-asparaginase or as a function of the L-asparaginase dose. The cell types compared were the mouse leukemia lines L5178Y (sensitive to L-asparaginase treatment) and L5178Y/L-ASE (resistant to L-asparaginase treatment). Upon L-asparaginase treatment both cell lines lost most of their cellular asparagine but, whereas the resistant cells exhibited the ability to rebound to about 50% of initial values, the sensitive cells did not. While previous work had suggested that asparagine-dependent glycine synthesis was essential for sensitive cells (but not in resistant cells), we found no difference in the glycine content of either of the two cell lines as a function of either time or dose that would support this hypothesis. Major differences between the two cell lines were seen in the content of the essential amino acids before treatment with L-asparaginase. After incubation without L-asparaginase the contents of the two cell lines became similar. These results are discussed in terms of possible mechanisms of L-asparaginase sensitivity and resistance.
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PMID:Amino acid content of L5178Y and L5178Y/L-ASE cells after L-asparaginase treatment. 408 39

Radiation is curative in many types of localized cancer, whereas chemotherapy is rarely curative in either localized or widespread cancer. For this reason, chemotherapy should never be employed in any situation where it might hinder or prevent the administration of a potentially curative dose of radiation. However, in Burkitt's tumor in Africa, where a multicentric origin seems to be much more probable, cyclophosphamide, 40 mg/kg intravenously repeated every 3 to 4 weeks, has occasionally been curative. In the treatment of Wilms' tumor, surgery, radiation and chemotherapy are essential for optimal results. In acute leukemia, chemotherapy with the conventional agents, as well as newer drugs such as cytosine arabinoside and L-asparaginase, is the treatment of choice, with radiation being useful mainly in treatment of localized disease in the bones or in the central nervous system. The great interest in L-asparaginase at the present time lies in the fact that certain neoplastic cells have a specific nutritional requirement for the amino acid L-asparagine, whereas no normal cells appear to have this requirement. In many cases of advanced neoplastic disease, the partnership of radiation therapy to reduce large bulky lesions composed to a large extent of nonproliferating cells, followed by chemotherapy to destroy the few surviving and now perhaps proliferating cells remaining in the original mass or in metastases, would seem to offer the greatest promise of theoretical and practical benefit.
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PMID:Chemotherapy and radiotherapy--competitors or partners? 437 33

L-Asparaginase (EC 3.5.1.1) inhibited respiration in sensitive, but not resistant, lines of murine lymphoma 6C3HED. Glucose, in these tumor lines, was principally converted to lactate, and very little was oxidized in the citric acid cycle or hexose monophosphate shunt. The cells derived 70-80% of their respiratory CO(2) from glutamine or glutamate. Asparaginase had no effect on the pattern of glucose utilization. The differential effect on oxygen consumption may result from the absence of asparagine synthetase in sensitive cells. Respiration may be inhibited by accumulation of the aspartate, the product of glutamate oxidation. Resistant lymphoma cells remove aspartate by converting it to asparagine. Sensitive cells, which lack asparagine synthetase, cannot make asparagine.
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PMID:Glutamate oxidation of 6C3HED lymphoma: effects of L-asparaginase on sensitive and resistant lines. 453 Feb 80

Production of a tumor-inhibitory asparaginase by submerged fermentation with Serratia marcescens ATCC 60 was studied to ascertain optimal nutritional conditions for large-scale production leading to enzyme purification studies. Five strains of S. marcescens were screened in shake-flask studies and were found to produce 0.8 to 3.7 IU/ml 48 hr after inoculation. The requirements for asparaginase production with S. marcescens ATCC 60, the high producing strain, included the following: 4% autolyzed yeast extract medium (initial pH 5.0), an incubation temperature of 26 C, and limited aeration for a zero level of dissolved oxygen during the fermentation. Addition of various carbohydrates to the fermentation medium did not enhance yields. The peak cell population in the fermentation medium and the maximal asparaginase yields occurred simultaneously. Highest enzyme yields were found when the pH of the fermentation cycle rose to approximately 8.5. Yields of 4 IU of asparaginase/ml of cell suspension have been obtained consistently in 40 to 42 hr from 10-liter volumes (500 ml/4-liter bottle) produced on a reciprocating shaker. Scale-up to a 60-liter fermentor yielded 3.1 IU/ml in 35 hr.
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PMID:Production of tumor-inhibitory L-asparaginase by submerged growth of Serratia marcescens. 490 34

Administration of either Escherichia coli asparaginase or guinea pig serum to C3H/HE mice with the 6C3HED lymphosarcoma is followed by depression of glycine in the tumor. This decrease in cellular glycine concentration does not occur in a tumor resistant to asparaginase. The inhibition of the lymphosarcoma by asparaginase can be reversed by intraperitoneal injection of asparagine or glycine. This reversal appears to be specific because lysine, threonine, serine, and aspartic acid were ineffective. Loss of cellular glycine may be more important than loss of asparagine because of the requirement for glycine in purine synthesis.
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PMID:Glycine inhibition of asparaginase. 490 4

The purification and properties of a tumor inhibitory l-asparaginase from Serratia marcescens are described. The following properties of the enzyme were examined: kinetics of the enzyme reaction, catalytic activity as a function of pH, boundary sedimentation velocity, electrophoresis on polyacrylamide gel, immuno-electrophoresis against homologous and heterologous antisera, immunodiffusion, blood clearance rate in mice, and inhibition of the 6C3HED lymphoma in C3H mice. Complete regression of this tumor was obtained with a smaller dose of the enzyme from S. marcescens than with enzyme from Escherichia coli. The reason for this difference was not evident from a comparison of several properties of the two enzymes.
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PMID:Purification and properties of L-asparaginase from Serratia marcescens. 499 52

The L-asparagine analog, 5-diazo-4-oxo-L-norvaline, specifically inactivates L-asparaginase and inhibits the growth of L-asparagine-dependent or L-asparaginase-sensitive tumor cells in culture. With 5-(14)C-labeled compound, a biphasic incorporation into sensitive cells occurs, but the inhibition of cell multiplication is manifest much later than the rapid phase of incorporation of the analog.
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PMID:5-Diazo-4-oxo-L-norvaline: reactive asparagine analog with biological specificity. 524 Aug 31


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