scholarly journals Expression of the v-src or v-fps oncogene increases fructose 2,6-bisphosphate in chick-embryo fibroblasts. Novel mechanism for the stimulation of glycolysis by retroviruses

1986 ◽  
Vol 236 (2) ◽  
pp. 595-599 ◽  
Author(s):  
L Bosca ◽  
M Mojena ◽  
J Ghysdael ◽  
G G Rousseau ◽  
L Hue
Keyword(s):  
Chick Embryo ◽  
Rous Sarcoma Virus ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Kinase Activation ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Rate Limiting ◽  
Stimulation Of

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.

scholarly journals Transformation-sensitive isoactin in passaged chick embryo fibroblasts transformed by Rous sarcoma virus.

1983 ◽  
Vol 96 (6) ◽  
pp. 1766-1771 ◽  
Author(s):  
D P Witt ◽  
D J Brown ◽  
J A Gordon
Keyword(s):  
Chick Embryo ◽  
Rous Sarcoma Virus ◽  
General Characteristic ◽  
Cellular Transformation ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Microfilament System ◽  
Alpha Actin

Transformation by Rous sarcoma virus (RSV) has been reported to block the expression of differentiated cell products in chicken cells. The expression of these proteins may or may not be suppressed when temperature-sensitive mutants are shifted from the nonpermissive to the permissive temperature. A general characteristic of cellular transformation is the disruption of the microfilament system. In passaged chick embryo fibroblast cultures (CEF), this system is principally composed of isomeric forms of actin designated alpha, beta, and gamma by their isoelectric focusing and when subjected to SDS-PAGE behavior. We present evidence that an alpha-actin in CEF cultures, identified by its electrofocusing behavior, retention in the cytoskeleton, and DNase 1 binding properties, is selectively and dramatically reduced in amount upon transformation by RSV. Little or no reduction is observed in the beta- and gamma-isoactins. The reduction of alpha-actin is shown to be reversible and transformation related by use of a temperature-sensitive mutant, tsNY68. The decrease in this transformation-sensitive isoactin is apparently due to a decrease in synthesis, though other possibilities are discussed. A specific decrease in a particular isoactin after transformation may give insight into the mechanism by which the microfilaments are normally maintained.

scholarly journals Transformation-specific cell killing by a cancer-associated galactosyltransferase acceptor and cellular binding

1982 ◽  
Vol 208 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Daniel K. Podolsky ◽  
Kurt J. Isselbacher
Keyword(s):  
Chick Embryo ◽  
Growth Inhibition ◽  
Rous Sarcoma Virus ◽  
Specific Cell ◽  
Permissive Temperature ◽  
Trypsin Treatment ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Intermediate Amount

Cancer-associated galactosyltransferase acceptor (CAGA glycoprotein), a small glycoprotein purified from human malignant effusion that selectively kills transformed cells, was tritiated by reductive methylation in the presence of NaB3H4. CAGA-glycoprotein-sensitive cells (baby-hamster kidney cells transformed by polyoma virus and chick-embryo fibroblasts infected with Ts68 temperature-sensitive mutant of Rous sarcoma virus grown at 37°C, the permissive temperature) bound 3–5-fold more 3H-labelled CAGA glycoprotein than did their CAGA-glycoprotein-resistant non-transformed counterparts. The Rous-sarcoma-virus-infected chick-embryo fibroblasts grown at non-permissive temperature (41°C) bound an intermediate amount of 3H-labelled CAGA glycoprotein; however, this intermediate amount appeared to be sufficient to induce inhibition of cell growth when the infected chick-embryo fibroblasts treated at 41°C were switched to 37°C. Binding of 3H-labelled CAGA glycoprotein was time- and temperature-dependent and was not inhibited by monosaccharide. Binding was completely inhibited by the oligosaccharide liberated by endoglucosaminidase H treatment or by exhaustive Pronase digestion of intact CAGA glycoprotein. However, the isolated oligosaccharide failed to demonstrate the growth-inhibition characteristics of the intact glycopeptide. Binding of 3H-labelled CAGA glycoprotein was unaffected by co-incubation with the peptide core released by endoglucosaminidase H treatment. 3H-labelled CAGA glycoprotein bound to intact cells could be removed by trypsin treatment up to 4h after addition of the glycoprotein but not thereafter. This time course paralleled the decreasing reversibility of growth inhibition. However, all 3H-labelled CAGA glycoprotein was found in the supernatant when cells were first disrupted by sonication followed by trypsin treatment for up to 12h. 3H-labelled CAGA glycoprotein linked to Sepharose 4B failed to cause growth inhibition in CAGA-glycoprotein-sensitive cells. These findings suggest that binding of CAGA glycoprotein occurs via its oligosaccharide moiety. Binding appears to be a necessary but not sufficient condition to induce cell killing. Growth inhibition appears to depend on internalization of the glycoprotein and the presence of a transformation-specific cell process.

scholarly journals Decreased levels of collagen mRNA in rous sarcoma virus-transformed chick embryo fibroblasts

1978 ◽  
Vol 253 (16) ◽  
pp. 5869-5874
Author(s):  
B.H. Howard ◽  
S.L. Adams ◽  
M.E. Sobel ◽  
I. Pastan ◽  
B. de Crombrugghe
Keyword(s):  
Chick Embryo ◽  
Rous Sarcoma Virus ◽  
Collagen Mrna ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts
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