THE MECHANISM OF PYRIDINE NUCLEOTIDE SYNTHESIS IN EHRLICH ASCITES CARCINOMA AND HOST LIVER

1967 ◽  
Vol 45 (2) ◽  
pp. 179-190 ◽  
Author(s):  
J. Purko ◽  
H. B. Stewart
Keyword(s):  
Nicotinic Acid ◽  
Ehrlich Ascites Carcinoma ◽  
Pyridine Nucleotide ◽  
Host Liver ◽  
Nucleotide Synthesis ◽  
Tumor Bearing ◽  
Ehrlich Ascites ◽  
Metabolic Products ◽  
Ehrlich Ascites Cells ◽  
Specific Activities

Labeled nicotinamide–adenine dinucleotide (NAD) and nicotinic acid–adenine dinucleotide (NacAD) were identified following Dowex 2 (formate) chromatography of extracts of Ehrlich ascites cells and of livers of mice 3 and 6 h after injection of nicotinamide (Nam) (500 mg/kg) containing Nam-7-14C, and 3 h after injection of nicotinic acid (Nac) (50 mg/kg) containing Nac-7-14C into tumor-bearing animals. Labeled Nac mononucleotide (NacMN) was also identified in the liver extracts. The urinary metabolic products of the precursors were separated and partially characterized. Liver appeared to be somewhat more active in synthesis of NAD than tumor; the more efficient amidation of NacAD to NAD in liver probably contributes to this difference. The results are consistent with NacAD being an intermediate in NAD biosynthesis. Investigations of extracts of acetone powders of tumor provided evidence for two possible routes of synthesis (via NMN, and NacMN–NacAD): (1) Extracts incubated with Nam mononucleotide (NMN) and ATP formed NAD. (2) Extracts incubated with Nac-14C or Nam-14C with suitable supplementation gave rise to labeled NacMN, NacAD and NAD. These substances were isolated and their specific activities determined. Glutamine appeared to enhance NAD formation at the expense of NacAD. Although a net accumulation of NAD did not occur, the formation of Nam-14C from Nac-14C and the demonstration of NADase in the preparations suggested that NAD was formed but rapidly degraded.

PARTICIPATION OF NICOTINAMIDE MONONUCLEOTIDE IN PYRIDINE NUCLEOTIDE SYNTHESIS IN TUMOR AND HOST LIVER

1967 ◽  
Vol 45 (3) ◽  
pp. 363-373 ◽  
Author(s):  
J. W. D. McDonald ◽  
H. B. Stewart
Keyword(s):  
Pyridine Nucleotide ◽  
Host Liver ◽  
Nucleotide Synthesis ◽  
Nicotinamide Mononucleotide ◽  
Ehrlich Ascites ◽  
Nad Synthesis ◽  
Ehrlich Ascites Cells ◽  
High Doses

Evidence is presented to show that nicotinamide-7-14C in low or high doses is incorporated into nicotinamide mononucleotide (NMN) by Ehrlich ascites cells and host liver in vivo. Nicotinamide mononucleotide formed from nicotinamide-7-14C has been isolated from incubations of Sephadex-treated extracts of ascites cell acetone powders with 5-phosphoribosyl-1-pyrophosphate and characterized by spectral and chemical analysis. The apparent Km and Vmax for NMN synthesis from nicotinamide have been determined. NMN-14C has been shown to form NAD-14C in the same extracts in the presence of ATP, and the apparent Vmax and Km of this process have been determined. The role of NMN in NAD synthesis is discussed.

Phosphorylation of Adenosine and Deoxyadenosine in Ehrlich Ascites Carcinoma Cells Resistant to 6-(Methylmercapto)purine Ribonucleoside

1972 ◽  
Vol 50 (4) ◽  
pp. 423-427 ◽  
Author(s):  
Christopher A. Lomax ◽  
J. Frank Henderson
Keyword(s):  
Mutant Cell ◽  
Ehrlich Ascites Carcinoma ◽  
Adenosine Kinase ◽  
Carcinoma Cells ◽  
Ehrlich Ascites Tumor Cells ◽  
Nucleotide Synthesis ◽  
Ehrlich Ascites ◽  
Mutant Strains ◽  
Selection For ◽  
Reduced Activity

The metabolism of adenosine and deoxyadenosine has been studied in Ehrlich ascites tumor cells and in a subline (EAC-R2) resistant to growth inhibition by 6-(methylmercapto)purine ribonucleoside (6MeMPR). The mutant cell line showed reduced rates of conversion of adenosine and deoxyadenosine into nucleotides. It was concluded from this that both compounds probably are phosphorylated by adenosine kinase. Comparison of the rates of nucleotide synthesis at increasing concentrations of adenosine indicated differences in the Km and Vmax values of the adenosine kinases in the parent and mutant strains. Competition experiments between adenosine and 6MeMPR showed that adenosine kinase in EAC-R2 had probably lost all affinity for the analogue. Selection for resistance to 6MeMPR therefore seems to have altered the structure of adenosine kinase, such that it has no activity with 6MeMPR and reduced activity with adenosine and deoxyadenosine.

Tube Leukocyte Adherence-Inhibition Response to Related and Unrelated Tumor Antigens in Mammary Tumor-Bearing Mice

1983 ◽  
Vol 69 (4) ◽  
pp. 299-303 ◽  
Author(s):  
Utpala Chattopadhyay ◽  
Surajit Guha
Keyword(s):  
Mammary Tumor ◽  
Tumor Antigens ◽  
Ehrlich Ascites Carcinoma ◽  
Tumor Burden ◽  
Leukocyte Adherence ◽  
Tumor Bearing ◽  
Inhibition Response ◽  
Ehrlich Ascites ◽  
Leukocyte Adherence Inhibition ◽  
Adherence Inhibition

Tube leukocyte adherence-inhibition response to syngeneic mammary tumor antigens and alloantigens from Ehrlich ascites carcinoma and fibrosarcoma was studied in spontaneous mammary tumor-bearing C3H/Jax mice. The mice with limited tumor burden responded significantly to the mammary tumor antigen and the Ehrlich ascites carcinoma antigen. The reactivity disappeared with increased tumor load. Oscillatory responses in leukocyte adherence inhibition to the reactive antigens was observed with increasing tumor weight. There was no response to the alloantigen of fibrosarcoma.

RESISTANCE TO 6-MERCAPTOPURINE: I. BIOCHEMICAL DIFFERENCES BETWEEN THE EHRLICH ASCITES CARCINOMA AND A 6-MERCAPTOPURINE-RESISTANT SUBLINE

1962 ◽  
Vol 40 (1) ◽  
pp. 181-194 ◽  
Author(s):  
A. R. P. Paterson ◽  
A. Hori
Keyword(s):  
Ehrlich Ascites Carcinoma ◽  
Cell Types ◽  
Nucleotide Metabolism ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Purine Nucleotide ◽  
Nucleotide Synthesis ◽  
Ehrlich Ascites ◽  
Purine Nucleotide Metabolism ◽  
Resistant Cells

A 6-mercaptopurine (6-MP)-resistant subline of the Ehrlich ascites carcinoma developed in this laboratory has been reported previously to lack the ability to synthesize thioinosinate, a characteristic believed to be related to mercaptopurine resistance. A comparison was made of various aspects of purine nucleotide metabolism in cells of the parent tumor line and the resistant subline in order to detect differences which, if they existed, might account for resistance to 6-MP.The synthesis of adenylate or of inosinate from adenine-8-C14was found to take place at similar rates in the two cell types under conditions in which adenylate renewal was independent of adenine-8-C14concentration. Both cell types synthesized adenylate and inosinate at comparable rates from hypoxanthine-8-C14and had equivalent adenylate deaminase activities. The size of the pool of inosinate in the tumor cells was measured by the isotope dilution method and that of the Ehrlich cells was found to be 1.6 times the pool size of the resistant cells. The conversion of guanine-8-C14to guanylate took place at similar rates in both tumors.In general, no differences in purine nucleotide metabolism were revealed which were obviously related to resistance or to the characteristic inability of the resistant subline to synthesize thioinosinate. This inability did not appear to be due to an inadequacy of the phosphoribosylpyrophosphate resources of the resistant cell, since the rates of purine nucleotide synthesis were similar in the two cell types. In Part II it is shown that extracts of the 6-MP-resistant cells catalyzed the synthesis of thioinosinate. It was concluded that the failure of intact resistant cells to synthesize thioinosinate was due to failure of 6-MP to enter the cell.

Effects of ethanol extract of Pisonia aculeata Linn. on ehrlich ascites carcinoma tumor bearing mice

2008 ◽  
Vol 2 (1) ◽  
pp. 50 ◽  
Author(s):  
Raju Senthilkumar ◽  
Rangasamy Manivannan ◽  
Ayyasamy Balasubramaniam ◽  
Thangavel Sivakumar ◽  
Balasubramanian Rajkapoor
Keyword(s):  
Ethanol Extract ◽  
Ehrlich Ascites Carcinoma ◽  
Tumor Bearing ◽  
Ehrlich Ascites ◽  
Carcinoma Tumor

THE BIOSYNTHESIS OF AMINO ACID ACCEPTOR RNA

1964 ◽  
Vol 42 (6) ◽  
pp. 859-870 ◽  
Author(s):  
R. A. Cook ◽  
J. P. Bouchard ◽  
M. J. Fraser
Keyword(s):  
Amino Acid ◽  
Tumor Cells ◽  
Actinomycin D ◽  
Ehrlich Ascites Carcinoma ◽  
Ehrlich Ascites ◽  
Specific Activities ◽  
Dna Template ◽  
Acceptor Capacity ◽  
Amino Acid Acceptor

Preliminary observations have been made on the biosynthesis of amino acid acceptor RNA in the mouse Ehrlich ascites carcinoma. Measurements have been made of the incorporation of radioactivity from either14C-CH3-methionine or uridine-2-14C into the RNA of nuclear and cytoplasmic fractions which precipitate at pH 5.0 from 105,000 × g supernatants of broken nuclei preparations and of cell homogenates ("soluble" RNA or sRNA). With either labelled precursor higher specific activities were found in the nuclear than in the cytoplasmic sRNA fractions. Whereas actinomycin D and DNase inhibited the incorporation of radioactivity from uridine-2-14C into nuclear sRNA, these agents stimulated significantly the incorporation of radioactivity from14C-CH3-methionine. The glycine acceptor capacity of nuclear sRNA was found to be greater than that of cytoplasmic sRNA. The base ratios of the amino acid acceptor RNA fractions derived from nuclear sRNA and from cytoplasmic sRNA by chromatography on methylated albumin columns were very similar. The results are consistent with the hypothesis that the amino acid acceptor RNA is made on a DNA-template in the nucleus of the tumor cells, is subsequently released from the template, methylated, and then transferred to the cytoplasm.

THIOPURINE NUCLEOTIDE SYNTHESIS IN A 6-MP-RESISTANT SUBLINE OF THE EHRLICH ASCITES CARCINOMA AND GROWTH INHIBITION BY CERTAIN ANTIMETABOLITES

1960 ◽  
Vol 38 (10) ◽  
pp. 1129-1135 ◽  
Author(s):  
A. R. P. Paterson
Keyword(s):  
Growth Inhibition ◽  
Tumor Cells ◽  
Test Dose ◽  
Ehrlich Ascites Carcinoma ◽  
Tumor Line ◽  
Nucleotide Synthesis ◽  
Parent Line ◽  
Ehrlich Ascites ◽  
Ascites Tumors ◽  
Hydrolysis Of

A 6-MP-resistant subline of the Ehrlich ascites carcinoma has been characterized as cross-resistant to thioguanine and is more sensitive to azaserine than the parent tumor line. The resistant subline has retained the sensitivity to amethopterin shown by the parent tumor line. 6-MP riboside was no more effective than 6-MP in inhibiting the growth of the resistant cells.It was shown previously that cells of this resistant subline, in contrast to cells of the parent line, were unable to synthesize 6-MP nucleotide from a test dose of 6-MP injected into the ascitic fluid. In the present study it was shown that resistant cells were also unable to convert 6-MP riboside or thioguanine to their nucleotide derivatives, both of which were synthesized by the 6-MP-sensitive parent line of tumor cells. Similarities observed in the metabolism of 6-MP and 6-MP riboside and in their chemotherapeutic effects were probably due to the extensive hydrolysis of 6-MP riboside which took place in both ascites tumors.

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.

scholarly journals Inhibition by derivatives of diguanidines of cell proliferation in Ehrlich ascites cells grown in cultures

1980 ◽  
Vol 188 (2) ◽  
pp. 491-501 ◽  
Author(s):  
L Alhonen-Hongisto ◽  
H Pösö ◽  
J Jänne
Keyword(s):  
Growth Inhibition ◽  
Ehrlich Ascites Carcinoma ◽  
Tumour Cells ◽  
Polyamine Metabolism ◽  
Decarboxylase Activity ◽  
Subsequent Formation ◽  
Adenosylmethionine Decarboxylase ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
In Cells

The anti-proliferative effects of 1,1′-[(methylethanediylidene)dinitrilo]diguanidine [methylglyoxal bis(guanylhydrazone)] and 1,1′-[(metHYLETHANEDIYLIDENE)dinitrilo]bis-(3-aminoguaNIDINE) HAVE BEEN STUDIED IN Ehrlich ascites carcinoma cells grown in suspension cultures. Both compounds are potent inhibitors of S-adenosyl-L-methionine decarboxylase from the tumour cells. In the presence of putrescine (but not in its absence), the inhibition produced by 1,1′-[methylethanediylidene)dinitrilo]bis-(3-aminoguanadine) was apparently irreversible, as judged by persistent depression of the enzyme activity even after extensive dialysis. The two compounds produced similar increases in adenosylmethionine decarboxylase activity, which resulted from a striking stabilization of the enzyme in cells grown in the presence of the drugs. The inhibitory effect of the two diguanidine derivatives on the synthesis of DNA and protein became evident after an exposure of 4–8 h. At that time, the only change seen in tumour polyamines in cells grown in the presence of the inhibitors was an increase in cellular putrescine. To find out whether the compounds initially interfered with the energy production of the tumour cells, the cultures were grown in the presence of uniformly labelled glucose, and the formation of lactate, as well as the oxidation of the sugar into CO2, were measured. The activation of glycolysis upon dilution of the tumour cells with fresh medium and the subsequent formation of labelled CO2 were siliar in control cells and in cells exposed to methylglyoxal bis(buanylhydrazone), 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine) or diaminopropanol. Only a marginal decrease in the cellular content of ATP was found in cells exposed to the inhibitors for 24 h. The diguanidine-induced growth inhibition was fully reversed by low concentrations of exogenous polyamines. However, the possibility remained that the reversal by polyamines was due to a decrease of intracellular diguanidine concentration. Our results indicate that the mode of action of 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine) is fully comparable to that of methylglyoxal bis(guanylhydrazone), as regards stabilization of adenosylmethionine decarboxylase and the appearance of growth inhibition in Ehrlich ascites cells. The data tend to support the view that both compounds apparently have an early anti-proliferative effect unrelated to polyamine metabolism.

Sign in / Sign up

Export Citation Format

Share Document