Effects of altered ribonucleotide concentrations on ribonucleotide reduction in intact Chinese hamster ovary cells

1981 ◽  
Vol 59 (10) ◽  
pp. 821-829 ◽  
Author(s):  
Darel Hunting ◽  
Joyce Hordern ◽  
J. Frank Henderson
Keyword(s):  
Chinese Hamster Ovary ◽  
Narrow Range ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Naturally Occurring ◽  
Wide Range ◽  
Ribonucleoside Triphosphate ◽  
Deoxyribonucleoside Triphosphate ◽  
The Relationship

The effect of changes in ribonucleoside triphosphate concentrations on those of deoxyribonucleotides has been determined in Chinese hamster ovary K-1 cells. Ribonucleoside triphosphate concentrations were manipulated by the use of drugs or naturally occurring purines or pyrimidines. Changes in the concentration of each ribonucleoside triphosphate led to changes in the concentration of each corresponding deoxyribonucleoside triphosphate. The relationships between the concentrations of CTP and dCTP and between those of GTP and dGTP were linear over a wide range. The relationship between the concentrations of ATP and dATP was linear over the narrow range studied, while the relationship between UTP and dTTP concentrations was curvilinear. Overall, these results demonstrate that ribonucleotides play an important role in controlling deoxyribonucleotide concentrations but the exact mechanism of this control remains to be determined.

Protein glycosylation in heat-sensitive and thermotolerance-deficient mutants of Chinese hamster ovary cells

1990 ◽  
Vol 95 (4) ◽  
pp. 555-561
Author(s):  
K.J. Henle ◽  
W.A. Nagle ◽  
J.S. Bedford ◽  
W.F. Harvey
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Protein Glycosylation ◽  
Heat Sensitivity ◽  
Ovary Cells ◽  
Cell Fractions ◽  
High Degree ◽  
The Relationship

Chinese hamster ovary (CHO) cells are capable of developing a high degree of thermotolerance in response to appropriate heat conditioning. In this study we examined the relationship between thermotolerance development and protein glycosylation using four sublines of CHO cells. Two of these CHO sublines are characterized by an increased heat sensitivity and impaired cellular capacity for thermotolerance development. The data show that thermotolerance development after heat conditioning in the heat-sensitive, thermotolerance-deficient mutants was accompanied by reduced labeling of a Mr 50,000 glycoprotein (GP50), in both soluble and insoluble cell fractions. Similarly, activation of UDP-N-acetylgalactosaminyltransferase (Gal-NAcT) after hyperthermia was almost completely abolished in these cell lines. Both of these endpoints have been correlated previously with thermotolerance expression. The data are consistent with the glycosylation hypothesis that attributes increased heat resistance of thermotolerant cells, at least in part, to enhanced glycosylation and accumulation of endogenous glycoproteins, such as GP50.

scholarly journals CHANGES IN SURFACE MORPHOLOGY OF CHINESE HAMSTER OVARY CELLS DURING THE CELL CYCLE

1973 ◽  
Vol 57 (3) ◽  
pp. 815-836 ◽  
Author(s):  
Keith Porter ◽  
David Prescott ◽  
Jearl Frye
Keyword(s):  
Cell Cycle ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Confluent Culture ◽  
Large Numbers ◽  
Wide Range ◽  
Surface Changes

Synchronized populations of Chinese hamster ovary (CHO) cells in confluent culture have been examined by scanning electron microscopy and their surface changes noted as the cells progress through the cycle. During G1 it is characteristic for cells to show large numbers of microvilli, blebs, and ruffles. Except for the ruffles, these tend to diminish in prominence during S and the cells become relatively smooth as they spread thinly over the substrate. During G2 microvilli increase in number and the cells thicken in anticipation of rounding up for mitosis. It appears that the changes observed here reflect the changing capacity of CHO cells during the cycle to respond to contact with other cells in the population, because, as noted in the succeeding paper (Rubin and Everhart), CHO cells in sparse nonconfluent cultures do not show the same wide range of changes during the cell cycle. Normal, nontransformed cells of equivalent type in confluent culture are essentially devoid of microvilli, blebs, and ruffles. The relation of these surface configurations to the internal structure of the cell is discussed.

Functional Properties of Two Naturally Occurring Isoforms of the Human Insulin Receptor in Chinese Hamster Ovary Cells*

Endocrinology ◽  
1991 ◽  
Vol 129 (4) ◽  
pp. 2058-2066 ◽  
Author(s):  
YOSHIHIKO YAMAGUCHI ◽  
JEFFREY S. FLIER ◽  
ATSUSHI YOKOTA ◽  
HEIKE BENECKE ◽  
JONATHAN M. BACKER ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Functional Properties ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Naturally Occurring ◽  
Human Insulin Receptor

scholarly journals Effects of turmeric and its active principle, curcumin, on bleomycin-induced chromosome aberrations in Chinese hamster ovary cells

1999 ◽  
Vol 22 (3) ◽  
pp. 407-413 ◽  
Author(s):  
Maria Cristina P. Araújo ◽  
Francisca da Luz Dias ◽  
Sergio N. Kronka ◽  
Catarina S. Takahashi
Keyword(s):  
Cell Cycle ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Active Principle ◽  
Chromosomal Damage ◽  
Ovary Cells ◽  
Naturally Occurring ◽  
Plant Constituents

Naturally occurring antioxidants have been extensively studied for their capacity to protect organisms and cells from oxidative damage. Many plant constituents including turmeric and curcumin appear to be potent antimutagens and antioxidants. The effects of turmeric and curcumin on chromosomal aberration frequencies induced by the radiomimetic agent bleomycin (BLM) were investigated in Chinese hamster ovary (CHO) cells. Three concentrations of each drug, turmeric (100, 250 and 500 <FONT FACE="Symbol">m</FONT>g/ml) and curcumin (2.5, 5 and 10 <FONT FACE="Symbol">m</FONT>g/ml), were combined with BLM (10 <FONT FACE="Symbol">m</FONT>g/ml) in CHO cells treated during the G1/S, S or G2/S phases of the cell cycle. Neither turmeric nor curcumin prevented BLM-induced chromosomal damage in any phases of the cell cycle. Conversely, a potentiation of the clastogenicity of BLM by curcumin was clearly observed in cells treated during the S and G2/S phases. Curcumin was also clastogenic by itself at 10 µg/ml in two protocols used. However, the exact mechanism by which curcumin produced clastogenic and potentiating effects remains unknown.

Comparison of purine and pyrimidine metabolism in G1 and S phases of HeLa and Chinese hamster ovary cells

1982 ◽  
Vol 60 (4) ◽  
pp. 422-433 ◽  
Author(s):  
Joyce Hordern ◽  
J. Frank Henderson
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
S Phase ◽  
Pyrimidine Metabolism ◽  
Ovary Cells ◽  
Size Dependent ◽  
Quantitative Studies ◽  
Deoxyribonucleoside Triphosphate ◽  
Rna And Dna

Detailed quantitative studies of purine and pyrimidine metabolism in G1 and S phases of synchronized HeLa and Chinese hamster ovary cells have been carried out. Concentrations of ribonucleoside triphosphates increased approximately in proportion to the increase in cell size as cells moved from G1 to S phase. Deoxyribonucleoside triphosphate concentrations were low in G1 phase and increased 2.5- to 10-fold in S phase. Pathways and rates of metabolism of radioactive adenine, guanosine, deoxyadenosine, deoxyguanosine, uridine, cytidine, deoxyuridine, deoxycytidine, and thymidine were determined by measuring the incorporation of each precursor into individual acid-soluble nucleotides and RNA and DNA bases. Cell-cycle or size-dependent differences were detected in many of the parameters studied.

Quantitative analysis of purine and pyrimidine metabolism in Chinese hamster ovary cells

1981 ◽  
Vol 59 (10) ◽  
pp. 838-847 ◽  
Author(s):  
Darel Hunting ◽  
Joyce Hordern ◽  
J. Frank Henderson
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Study ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Pyrimidine Metabolism ◽  
Ovary Cells ◽  
Direct Measurements ◽  
Deoxyribonucleoside Triphosphate ◽  
Pool Sizes

A detailed quantitative study of purine and pyrimidine metabolism in logarithmically growing Chinese hamster ovary cells has been performed. Direct measurements of the ribonucleoside and deoxyribonucleoside triphosphate pool sizes have been made, and the pathways and rates of metabolism of adenine, hypoxanthine, guanine, guanosirae, deoxyadenosine, and deoxyguanosine and of uridine, cytidine, deoxyeytidine, deoxyuridine, and thymidine have been determined.

Antimutagenic activities of naturally occurring polyamines in Chinese hamster ovary cells in vitro

1991 ◽  
Vol 18 (3) ◽  
pp. 207-211 ◽  
Author(s):  
Renata Cozzi ◽  
Paolo Perticone ◽  
Roberta Bona ◽  
Stefania Polani ◽  
D. A. Casciano
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Naturally Occurring

Regulation of ribonucleotide reduction by deoxyribonucleotides in intact Chinese hamster ovary cells

1981 ◽  
Vol 59 (10) ◽  
pp. 830-837 ◽  
Author(s):  
Darel Hunting ◽  
J. Frank Henderson
Keyword(s):  
Ribonucleotide Reductase ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Nucleoside Triphosphate ◽  
Ovary Cells ◽  
Naturally Occurring

The ribonucleotide reductase model of Thelander and Reichard, which is based on studies of the purified enzyme, has been tested in cultured Chinese hamster ovary K-1 cells. Deoxyribo-nucleoside triphosphate concentrations were manipulated by the use of drugs or naturally occurring deoxyribonucleosides, and ribo- and deoxyribo-nucleoside triphosphate concentrations were measured. The results are consistent with the hypothesis that dTTP inhibits CDP reduction and stimulates GDP reduction, and that dGTP inhibits CDP reduction. However, the results are contrary to the hypothesis that dGTP inhibits UDP reduction and stimulates ADP reduction. and that dATP inhibits CDP reduction. It is concluded that the model of Thelander and Reichard applies only in part to intact CHO cells.

Sign in / Sign up

Export Citation Format

Share Document