scholarly journals Effect of 5‘-deoxy-5’-isobutylthioadenosine on putrescine uptake and polyamine biosynthesis by chick embryo fibroblasts

1982 ◽  
Vol 204 (3) ◽  
pp. 853-859 ◽  
Author(s):  
F Lawrence ◽  
U Bachrach ◽  
M Robert-Géro

The effect of 5‘-deoxy-5’-S-isobutylthioadenosine (SIBA) on polyamine biosynthesis has been studied by using cultured chick embryo fibroblasts. It has been shown that the drug inhibits the uptake of [14C]putrescine and its conversion into labelled spermidine or spermine. The inhibitory effect is reversed by removing the inhibitor after exposing the cells to the drug for 24 h. SIBA also caused a significant decrease in cellular spermine levels and an accumulation of putrescine. These changes are reversed by removing the inhibitor. SIBA had the same effect on chick embryo fibroblasts transformed by Rous sarcoma virus; a decrease in cellular spermine levels in SIBA-treated cells was observed. In all the experiments SIBA caused a reduction in the spermine/putrescine and spermidine/putrescine ratios. It is suggested that SIBA is not only an inhibitor of transmethylation but also interferes with polyamine biosynthesis, probably by blocking aminopropyltransferase.

1978 ◽  
Vol 253 (16) ◽  
pp. 5869-5874
Author(s):  
B.H. Howard ◽  
S.L. Adams ◽  
M.E. Sobel ◽  
I. Pastan ◽  
B. de Crombrugghe

1976 ◽  
Vol 22 (10) ◽  
pp. 1474-1479
Author(s):  
Lorraine Leblond-Larouche ◽  
Réjean Morais

Attempts have been made to keep in vitro, for extended periods of time, cultures of chick embryo fibroblasts transformed by the Schmidt–Ruppin strain of Rous sarcoma virus, subgroup D. Roller cultures of transformed chick cells kept in serum-deficient medium can be maintained without subcultivation for up to 6 months. The confluent cultures continuously release viruses and viable tumor cells into the medium. The released cells can be plated and have characteristics of growth and morphology which are relatively stable with time until the culture degenerates. Cells released at later stages of the culture produced substantially more viruses than those released earlier, suggesting that cell selection or differentiation occurs during long-term cultivation in low serum concentration. Long-term cultures of untransformed chick embryo fibroblasts can also be maintained in the same way. The release of viable cells by these confluent cultures, however, is negligible.


1986 ◽  
Vol 236 (2) ◽  
pp. 595-599 ◽  
Author(s):  
L Bosca ◽  
M Mojena ◽  
J Ghysdael ◽  
G G Rousseau ◽  
L Hue

The concentration of fructose 2,6-bisphosphate and the activity of 6-phosphofructo-2-kinase are increased after infection of chick-embryo fibroblasts with the Rous sarcoma virus, or with a temperature-sensitive mutant of this virus at the permissive, but not at the non-permissive, temperature. This is observed after transformation by retroviruses carrying either the v-src or v-fps, but not the v-mil and/or v-myc, oncogenes. Comparison of the effects of the Rous sarcoma virus with those of phorbol myristate acetate on fructose 2,6-bisphosphate suggests that both result from the stimulation of a step which is rate-limiting for 6-phosphofructo-2-kinase activation and which is also controlled by protein kinase C.


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