THE SYNTHESIS OF EXTRACELLULAR RIBONUCLEOSIDES BY ASCITES TUMOR CELLS IN VITRO

1965 ◽  
Vol 43 (2) ◽  
pp. 257-269 ◽  
Author(s):  
A. R. P. Paterson
Keyword(s):  
Tumor Cells ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Ascites Tumor ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells

Ehrlich ascites carcinoma cells in vitro converted extracellular hypoxanthine to extracellular inosine if uridine or guanosine was provided in the medium at the rate of 20–30 μmoles per milliliter of cells per hour. The synthesis of external uridine also took place when cells were incubated with uracil and a purine ribonucleoside, but at a lower rate than that of inosine. Intact Ehrlich ascites cells catalyzed an exchange between labelled uracil and uridine when both were present in the incubation medium.The synthesis of the extracellular ribonucleoside appeared to be mediated by ribonucleoside phosphorylases and to take place by the transfer of the ribosyl group from a donor ribonucleoside to an acceptor base.

THE ENZYMIC FORMATION OF 6-(METHYLMERCAPTO)PURINE RIBONUCLEOSIDE 5′-PHOSPHATE

1966 ◽  
Vol 44 (2) ◽  
pp. 229-245 ◽  
Author(s):  
Ian C. Caldwell ◽  
J. Frank Henderson ◽  
A. R. P. Paterson
Keyword(s):  
Tumor Cells ◽  
Blood Cells ◽  
Intraperitoneal Injection ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Ehrlich Ascites ◽  
Mouse Tissues ◽  
Enzymatic Methods

6-(Methylmercapto)purine ribonucleoside (Me6MPR) is efficiently phosphorylated in mouse tissues and in Ehrlich ascites carcinoma cells in vivo; tumor cells in vitro and cell-free extracts of the tumor also phosphorylate this analogue ribonucleoside. The product of this reaction has been identified by chemical and enzymatic methods and by its chromatographic behaviour as Me6MPR 5′-phosphate. The evidence presented in this report indicates that no other major metabolites of Me6MPR are formed.The phosphorylation of Me6MPR by cell-free tumor extracts requires ATP and Mn2+ (or Mg2+), and evidence is presented that the reaction is probably mediated by adenosine kinase.Me-14C-6MPR is rapidly taken up by most mouse tissues following its intraperitoneal injection. Forty minutes after injection of the labeled drug, the highest levels of radioactivity were found in intestine, liver, blood cells, lung, and spleen, in descending order; virtually no radioactivity was found in brain tissue or in blood plasma.

ARGININE UPTAKE AND ARGINASE ACTIVITY IN EHRLICH ASCITES CARCINOMA CELLS

1959 ◽  
Vol 37 (4) ◽  
pp. 589-598 ◽  
Author(s):  
R. M. Johnstone
Keyword(s):  
Amino Acids ◽  
Tumor Cells ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Arginase Activity ◽  
Anaerobic Glycolysis ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Arginine Uptake ◽  
Ehrlich Ascites

Anaerobic glycolysis in Ehrlich ascites tumor cells exposed to amino acids leads to an increased uptake of a number of the amino acids to levels comparable with those obtained under aerobic conditions. The arginine uptake in the cell is not increased by glucose. Anaerobically the arginase activity is inhibited when glucose is present. The inhibition appears to be the result of an increased retention in the cell of the ornithine produced by arginase activity.

ARGININE UPTAKE AND ARGINASE ACTIVITY IN EHRLICH ASCITES CARCINOMA CELLS

1959 ◽  
Vol 37 (1) ◽  
pp. 589-598 ◽  
Author(s):  
R. M. Johnstone
Keyword(s):  
Amino Acids ◽  
Tumor Cells ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Arginase Activity ◽  
Anaerobic Glycolysis ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Arginine Uptake ◽  
Ehrlich Ascites

Anaerobic glycolysis in Ehrlich ascites tumor cells exposed to amino acids leads to an increased uptake of a number of the amino acids to levels comparable with those obtained under aerobic conditions. The arginine uptake in the cell is not increased by glucose. Anaerobically the arginase activity is inhibited when glucose is present. The inhibition appears to be the result of an increased retention in the cell of the ornithine produced by arginase activity.

The Degradation of Newly Synthesized RNA in Ehrlich Ascites Tumor Cells

1973 ◽  
Vol 51 (5) ◽  
pp. 495-505 ◽  
Author(s):  
Richard G. von Tigerstrom
Keyword(s):  
Tumor Cells ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
The Stability

The stability of rapidly labelled RNA in Ehrlich ascites tumor cells under in vitro conditions was investigated. [2-14C]Uridine was effectively incorporated into RNA and 90% of the acid-insoluble isotope was associated with the nucleus after 30 min labelling. When RNA synthesis was inhibited by actinomycin D or when [14C]uridine was chased with [12C]uridine at this time, a rapid degradation of approximately 50% of the labelled RNA could be observed. The rates of degradation, the extent of degradation under certain incubation conditions, and the classes of RNA from which the isotope was released were almost identical when the two chase techniques were compared. The concentration of uridine used during the chase did not inhibit RNA synthesis significantly as judged from incorporation of [8-14C]guanine. The results indicated that the degradation of the newly synthesized RNA in Ehrlich ascites cells occurred naturally and was not induced by actinomycin D.

Die Wirkung von 9.10-Phenanthrenhydrochinon-bisglycylester auf den Ehrlich-Ascites-Tumor der Maus und das Jensen-Sarkom der Ratte

1963 ◽  
Vol 18 (12) ◽  
pp. 1053-1056 ◽  
Author(s):  
U. Dold ◽  
H. J. Risse ◽  
H. Tiedemann
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Redox Cycle ◽  
Ascites Tumor ◽  
Low Oxygen ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
Ascites Tumors ◽  
Hydrolysis Of

9.10-phenanthrahydroquinone formed by the enzymatic hydrolysis of 9.10-phenanthrahydroquinone-bisglycylester undergoes a redox-cycle in tumor-cells. H2O2 is formed during the autoxidation of the hydroquinone. The amount of H2O2 is especially large in aerobically glycolyzing cells.The cancerostatic action of the hydroquinone-bisglycylester was tested on Ehrlich-Ascites-carcinoma-cells and on Jensen-sarcoma. When Ehrlich-Ascites-cells preincubated with 3.4 to 8.4·10-5 Mol/l Ester for 30 minutes at 37°C are injected into mice, the development of Ascites-tumors is inhibited. Injection of the ester directly into Ascites-tumors has no effect. One of the reasons for this may be the low oxygen content of the Ascites-tumor, which does not permit the redox-cycle to operate.In a part of the cases full regression of Jensen-sarcoma was obtained after injecting 8.2·10-5 Mol/kg Ester 2 - 3 times intravenously every of 2 -3 days.

INHIBITION OF RIBONUCLEOSIDE METABOLISM IN EHRLICH ASCITES TUMOR CELLS BY PURINE ANALOGUE RIBONUCLEOSIDES

1965 ◽  
Vol 43 (10) ◽  
pp. 1701-1710 ◽  
Author(s):  
A. R. P. Paterson ◽  
A. I. Simpson
Keyword(s):  
Tumor Cells ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Ehrlich Ascites Tumor Cells ◽  
Purine Analogues ◽  
Intact Cells ◽  
Ehrlich Ascites ◽  
Derivatives Of ◽  
Related Compounds

Several aspects of the metabolism of inosine and uridine by Ehrlich ascites carcinoma cells in vitro have been found to be inhibited by ribonucleoside derivatives of four purine analogues. The synthesis of both inosine and uridine by intact tumor cells was profoundly inhibited in the presence of 6-methylmercaptopurine ribonucleoside. Also inhibited were inosine and uridine cleavage, and the exchange of isotope between these ribonucleosides and the corresponding C14 labelled bases. These reactions, however, were not inhibited when they took place in broken-cell preparations. Similarly, inosine metabolism in intact cells (but not in broken cells) was profoundly inhibited by three related compounds: the ribonucleosides of the 6-chloro, 6-methylmercapto, and 6-propylmercapto derivatives of 2-aminopurine.

METABOLISM OF 6-MERCAPTOPURINE RIBONUCLEOSIDE BY EHRLICH ASCITES CARCINOMA CELLS

1964 ◽  
Vol 42 (10) ◽  
pp. 1415-1423 ◽  
Author(s):  
A. R. P. Paterson ◽  
Aiko Sutherland
Keyword(s):  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Glycosidic Linkage ◽  
Ascites Tumor ◽  
Resistant Line ◽  
Cell Compartment ◽  
Ehrlich Ascites ◽  
A Cell ◽  
Derivatives Of

Ribonucleoside derivatives of 6-mercaptopurine (6-MP) and other purine bases were rapidly catabolized when incubated with Ehrlich ascites carcinoma cells in vitro. The catabolism of purine ribonucleosides proceeded by way of phosphorolytic cleavage of the glycosidic linkage and resulted in accumulation of the liberated base in the incubation medium. The ribosyl portions of ribonucleoside substrates were utilized with the formation of lactate, which also appeared extracellularly.Cells of a 6-MP-resistant subline of the Ehrlich ascites tumor degraded 6-MP ribonucleoside (6-MPR) at rates comparable to those of the parent line. This finding, when considered with other characteristics of the resistant line of cells, implied that cleavage of 6-MPR took place in a cell compartment from which inosinate pyrophosphorylase was absent.

EFFECT OF X-IRRADIATION ON DNA SYNTHESIS IN EHRLICH ASCITES CARCINOMA CELLS

1965 ◽  
Vol 43 (7) ◽  
pp. 859-864 ◽  
Author(s):  
Shan-Ching Sung
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Total Rna ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
X Irradiation

The rate of DNA synthesis in Ehrlich ascites cells measured immediately after X-irradiation of 500 r for 6 minutes in vitro showed about 15% reduction. However, if X-irradiation was followed by preincubation of the cells, the subsequent synthesis of DNA in the X-irradiated cells was markedly inhibited. Under the same condition, the uptake of thymidine-2-C14, uridine-2-C14, adenine-8-C14, and glycine-1-C14, and protein synthesis in the X-irradiated cells were found to be almost the same as those in the non-irradiated control. RNA synthesis measured as total RNA was only slightly inhibited.

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