scholarly journals Expression of vascular endothelial growth factor does not promote transformation but confers a growth advantage in vivo to Chinese hamster ovary cells.

1993 ◽  
Vol 91 (1) ◽  
pp. 160-170 ◽  
Author(s):  
N Ferrara ◽  
J Winer ◽  
T Burton ◽  
A Rowland ◽  
M Siegel ◽  
...  
2017 ◽  
Vol 68 (4) ◽  
pp. 326-329
Author(s):  
Piotr Barć ◽  
Tomasz Płonek ◽  
Dagmara Baczyńska ◽  
Artur Pupka ◽  
Wojciech Witkiewicz ◽  
...  

1988 ◽  
Vol 8 (5) ◽  
pp. 2229-2232 ◽  
Author(s):  
A M Brunner ◽  
L E Gentry ◽  
J A Cooper ◽  
A F Purchio

Analyses of cDNA clones coding for simian type 1 transforming growth factor beta (TGF-beta 1) suggest that there are three potential sites for N-linked glycosylation located in the amino terminus of the precursor region. Analysis of [3H]glucosamine-labeled serum-free supernatants from a line of Chinese hamster ovary cells which secrete high levels of recombinant TGF-beta 1 indicate that the TGF-beta 1 precursor, but not the mature form, is glycosylated. Digestion with neuraminidase resulted in a shift in migration of the two TGF-beta 1 precursor bands, which suggests that they contain sialic acid residues. Endoglycosidase H had no noticeable effect. Treatment with N-glycanase produced two faster-migrating sharp bands, the largest of which had a molecular weight of 39 kilodaltons. TGF-beta 1-specific transcripts produced by SP6 polymerase programmed the synthesis of a 42-kilodalton polypeptide which, we suggest, is the unmodified protein backbone of the precursor. Labeling with 32Pi showed that the TGF-beta 1 precursor was phosphorylated in the amino portion of the molecule.


1983 ◽  
Vol 3 (8) ◽  
pp. 1468-1477
Author(s):  
K D Mehta ◽  
R S Gupta

Stable mutants which are approximately three- and eightfold resistant to the pyrazolopyrimidine nucleosides formycin A and formycin B (FomR) have been selected in a single step from mutagenized Chinese hamster ovary cells. In cell extracts, the two FomR mutants which were examined were both found to contain no measurable activity of the enzyme adenosine kinase (AK). However, cross-resistance studies with other adenosine analogs such as toyocamycin and tubercidin show that these mutants are distinct from toyocamycin or tubercidin resistant (Toyr) mutants which also contain no measurable AK activity in cell extracts. Studies on the uptake and incorporation of [3H]adenosine and [3H]tubercidin by various mutants and parental cell lines show that unlike the Toyr mutants, which are severely deficient in the phosphorylation of these compounds, the FomR mutants possess nearly normal capacity to phosphorylate these compounds and incorporate them into cellular macromolecules. These results suggest that the FomR mutants contain normal levels of AK activity in vivo. In cell hybrids formed between FomR X FomS cells and FomR X Toyr cells, the formycin-resistant phenotype of both of the FomR mutants behaved codominantly. However, the extracts from these hybrid cells contained either congruent to 50% (FomR X FomS) or no measurable (FomR X Toyr) AK activity, indicating that the lesion in these mutants neither suppresses the wild-type AK activity nor complements the AK deficiency of the Toyr mutants. The presence of AK activity in the FomR mutants in vivo, but not in their cell extracts, along with the codominant behavior of the mutants in hybrids, indicates that the lesions in the FomR mutant are of a novel nature. It is suggested that the genetic lesion in these mutants affects AK activity indirectly and that it may involve an essential cellular function which exists in a complex form with AK. Some implications of these results regarding the mechanism of action of formycin B are discussed.


2002 ◽  
Vol 115 (12) ◽  
pp. 2559-2567 ◽  
Author(s):  
Teresa Odorisio ◽  
Cataldo Schietroma ◽  
M. Letizia Zaccaria ◽  
Francesca Cianfarani ◽  
Cecilia Tiveron ◽  
...  

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family, comprising at least five cytokines specifically involved in the regulation of vascular and/or lymphatic endothelium differentiation. Several lines of evidence indicate a role for PlGF in monocyte chemotaxis and in potentiating the activity of VEGF, but the exact function of this cytokine is not fully understood. To define the biological role of PlGF in vivo, we have produced a transgenic mouse model overexpressing this factor in the skin by using a keratin 14 promoter cassette. Our data indicate that PlGF has strong angiogenic properties in both fetal and adult life. PlGF overexpression results in a substantial increase in the number,branching and size of dermal blood vessels as well as in enhanced vascular permeability. Indeed, intradermally injected recombinant PlGF was able to induce vessel permeability in wild-type mice. The analysis of vascular endothelial growth factor receptor 1/flt-1 and vascular endothelial growth factor receptor 2/flk-1 indicates that the two receptors are induced in the skin endothelium of transgenic mice suggesting that both are involved in mediating the effect of overexpressed PlGF.


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