scholarly journals FIBRINOLYSIS ASSOCIATED WITH ONCOGENIC TRANSFORMATION

1973 ◽  
Vol 138 (5) ◽  
pp. 1056-1064 ◽  
Author(s):  
L. Ossowski ◽  
J. P. Quigley ◽  
G. M. Kellerman ◽  
E. Reich
Keyword(s):  
Liquid Medium ◽  
Exponential Growth ◽  
Soft Agar ◽  
Transformed Cells ◽  
Oncogenic Transformation ◽  
3T3 Cells ◽  
Fetal Bovine ◽  
Embryo Fibroblasts ◽  
And Control

Fetal bovine and dog serum were selectively freed of plasminogen by affinity chromatography. The resulting serum as well as native and reconstituted serum (obtained by the addition of purified plasminogen to the plasminogen-depleted serum) were used to examine the role of plasminogen in (a) growth of normal and SV-40-transformed hamster embryo fibroblasts in liquid medium, (b) growth of SV-40-transformed hamster embryo fibroblasts in soft agar, (c) aggregation — a characteristic morphological change of SV-40-transformed hamster cells, and (d) migration of SV-40-transformed and control 3T3 cells from a monolayer into a "wound." The results demonstrated that exponential growth of both normal and transformed cells in liquid medium proceeded at the same rate in the presence or absence of plasminogen. In contrast, removal of plasminogen markedly depressed the plating efficiency of transformed cells in soft agar, eliminated their characteristic aggregation, and substantially reduced the extent of migration. The role of plasminogen and its activation in oncogenic transformation is discussed.

Role of Ca2+ in serum-stimulated Na+ influx in normal and transformed cells

1985 ◽  
Vol 248 (3) ◽  
pp. C288-C295 ◽  
Author(s):  
N. E. Owen ◽  
M. L. Villereal
Keyword(s):  
Human Lung ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Lung Fibroblasts ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Calmodulin Antagonist ◽  
Human Foreskin Fibroblasts ◽  
Swiss 3T3

Previous studies in human foreskin fibroblasts suggested that the mechanism by which serum stimulates Na+ influx is via a Ca2+-calmodulin-mediated event. In the present experiments in normal WI-38 cells (human lung fibroblasts), both the intracellular Ca2+ antagonist 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8) and the potent calmodulin antagonist trifluoperazine (TFP) blocked serum-stimulated Na+ influx [TMB-8 concentration causing half-maximal inhibition (Ki) = 15 microM and TFP Ki = 10 microM]. Similar results were obtained in Swiss 3T3 cells. In contrast, in transformed WI-38 or Swiss 3T3 cells neither TMB-8 nor TFP had any effect on serum-stimulated Na+ influx (TMB-8 Ki greater than 100 microM and TFP Ki greater than 100 microM). In addition, when 45Ca2+ efflux measurements were made on normal and transformed cells, serum stimulated significant 45Ca2+ efflux (P less than 0.05) from WI-38 and Swiss 3T3 cells, while having no effect on 45Ca2+ efflux from simian virus 40 (SV40)-WI-38 or SV40-Swiss 3T3 cells. However, an elevation of intracellular Ca2+ can stimulate Na+ influx, since it was found that A23187 mimicked the effects of serum in both normal and transformed cells. These results suggest that the Ca2+-calmodulin-mediated event, which is thought to be involved in serum-stimulated Na+ influx in normal cells, may be bypassed or overridden in transformed cells.

Existence of different Fos/Jun complexes during the G0-to-G1 transition and during exponential growth in mouse fibroblasts: differential role of Fos proteins

1992 ◽  
Vol 12 (11) ◽  
pp. 5015-5023
Author(s):  
K Kovary ◽  
R Bravo
Keyword(s):  
Exponential Growth ◽  
S Phase ◽  
3T3 Cells ◽  
Mouse Fibroblasts ◽  
Quiescent Cells ◽  
Serum Stimulation ◽  
Fos Protein ◽  
Swiss 3T3 ◽  
Stimulation Of

We have determined the different Fos/Jun complexes present in Swiss 3T3 cells either following serum stimulation of quiescent cells or during exponential growth by immunoprecipitation analyses. We have shown that while c-Fos is the major Fos protein associated with the Jun proteins (c-Jun, JunB, and JunD) soon after serum stimulation, at later times Fra-1 and Fra-2 are the predominant Fos proteins associated with the different Jun proteins. During exponential growth, the synthesis of Fra-1 and Fra-2 is maintained at a significant level, in contrast to c-Fos and FosB, which are expressed at very low or undetectable levels. Consequently, Fra-1 and Fra-2 are the main Fos proteins complexed with the Jun proteins in asynchronously growing cells. To determine whether the Fos proteins are differentially required during the G0-to-G1 transition and exponential growth for the entrance into S phase, we microinjected affinity-purified antibodies directed against c-Fos, FosB, Fra-1, and Fra-2. We have found that while the activities of c-Fos and FosB are required mostly during the G0-to-G1 transition, Fra-1 and Fra-2 are involved both in the G0-to-G1 transition and in asynchronous growth.

scholarly journals Resistance to oncogenic transformation in revertant R1 of human ras-transformed NIH 3T3 cells.

1989 ◽  
Vol 9 (5) ◽  
pp. 2258-2263 ◽  
Author(s):  
N Kuzumaki ◽  
Y Ogiso ◽  
A Oda ◽  
H Fujita ◽  
H Suzuki ◽  
...  
Keyword(s):  
Simian Virus 40 ◽  
Soft Agar ◽  
Simian Virus ◽  
T Antigen ◽  
Oncogenic Transformation ◽  
3T3 Cells ◽  
Cellular Mechanisms ◽  
Ras Gene ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

A flat revertant, R1, was isolated from human activated c-Ha-ras-1 (hu-ac-Ha-ras) gene-transformed NIH 3T3 cells (EJ-NIH 3T3) treated with mutagens. R1 contained unchanged transfected hu-ac-Ha-ras DNA and expressed high levels of hu-ac-Ha-ras-specific mRNA and p21 protein. Transfection experiments revealed that NIH 3T3 cells could be transformed by DNA from R1 cells but R1 cells could not be retransformed by Kirsten sarcoma virus, DNA from EJ-NIH 3T3 cells, hu-ac-Ha-ras, v-src, v-mos, simian virus 40 large T antigen, or polyomavirus middle T antigen. Somatic cell hybridization studies showed that R1 was not retransformed by fusion with NIH 3T3 cells and suppressed anchorage independence of EJ-NIH 3T3 and hu-ac-Ha-ras gene-transformed rat W31 cells in soft agar. These results suggest that the reversion and resistance to several oncogenes in R1 is due not to cellular defects in the production of the transformed phenotype but rather to enhancement of cellular mechanisms that suppress oncogenic transformation.

scholarly journals Existence of different Fos/Jun complexes during the G0-to-G1 transition and during exponential growth in mouse fibroblasts: differential role of Fos proteins.

1992 ◽  
Vol 12 (11) ◽  
pp. 5015-5023 ◽  
Author(s):  
K Kovary ◽  
R Bravo
Keyword(s):  
Exponential Growth ◽  
S Phase ◽  
3T3 Cells ◽  
Mouse Fibroblasts ◽  
Quiescent Cells ◽  
Serum Stimulation ◽  
Fos Protein ◽  
Swiss 3T3 ◽  
Stimulation Of

We have determined the different Fos/Jun complexes present in Swiss 3T3 cells either following serum stimulation of quiescent cells or during exponential growth by immunoprecipitation analyses. We have shown that while c-Fos is the major Fos protein associated with the Jun proteins (c-Jun, JunB, and JunD) soon after serum stimulation, at later times Fra-1 and Fra-2 are the predominant Fos proteins associated with the different Jun proteins. During exponential growth, the synthesis of Fra-1 and Fra-2 is maintained at a significant level, in contrast to c-Fos and FosB, which are expressed at very low or undetectable levels. Consequently, Fra-1 and Fra-2 are the main Fos proteins complexed with the Jun proteins in asynchronously growing cells. To determine whether the Fos proteins are differentially required during the G0-to-G1 transition and exponential growth for the entrance into S phase, we microinjected affinity-purified antibodies directed against c-Fos, FosB, Fra-1, and Fra-2. We have found that while the activities of c-Fos and FosB are required mostly during the G0-to-G1 transition, Fra-1 and Fra-2 are involved both in the G0-to-G1 transition and in asynchronous growth.

scholarly journals Tropomyosin-2 cDNA lacking the 3' untranslated region riboregulator induces growth inhibition of v-Ki-ras-transformed fibroblasts.

1997 ◽  
Vol 8 (5) ◽  
pp. 897-908 ◽  
Author(s):  
R A Janssen ◽  
J W Mier
Keyword(s):  
Growth Inhibition ◽  
Tumor Cells ◽  
Growth Rates ◽  
Untranslated Region ◽  
Soft Agar ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Transformed Fibroblasts ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

The levels of high molecular weight isoforms of tropomyosin (TM) are markedly reduced in ras-transformed cells. Previous studies have demonstrated that the forced expression of tropomyosin-1 (TM-1) induces reversion of the transformed phenotype of ras-transformed fibroblasts. The effects of the related isoform TM-2 on transformation are less clear. To assess the effects of forced expression of the TM-2 protein on ras-induced tumorigenicity, we introduced a TM-2 cDNA lacking the 3' untranslated region riboregulator into ras-transformed NIH 3T3 fibroblasts. TM-2 expression resulted in a flatter cell morphology and restoration of stress fibers. TM-2 expression also significantly reduced growth rates in low serum, soft agar, and nude mice. The reduced growth rates were associated with a prolongation of G0-G1. To identify the mechanism of TM-2-induced growth inhibition, we analyzed the effects of TM-2 reexpression of ERK and c-jun N-terminal kinase (JNK) activities. Levels of ERK phosphorylation and activity in TM-2-transfected tumor cells were comparable to those in mock-transfected tumor cells. JNK activity was only modestly increased in ras-transformed cells relative to untransformed NIH 3T3 cells and only slightly reduced as result of forced TM-2 expression. We conclude that the partially restored expression of the TM-2 protein induces growth inhibition of ras-transformed NIH 3T3 cells without influencing ERK or JNK activities. Furthermore, the 3' untranslated region riboregulator of the alpha-tropomyosin gene is not needed for the inhibition of ras-induced growth.

scholarly journals Suppression of tumorigenicity in transformed cells after transfection with vinculin cDNA.

1992 ◽  
Vol 119 (2) ◽  
pp. 427-438 ◽  
Author(s):  
J L Rodríguez Fernández ◽  
B Geiger ◽  
D Salomon ◽  
I Sabanay ◽  
M Zöller ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Suppressive Effect ◽  
Soft Agar ◽  
Transformed Cells ◽  
Tumor Cell Lines ◽  
3T3 Cells ◽  
Apparent Increase ◽  
Cell Matrix ◽  
Endogenous Protein

Transfection of chicken vinculin cDNA into two tumor cell lines expressing diminished levels of the endogenous protein, brought about a drastic suppression of their tumorigenic ability. The SV-40-transformed Balb/c 3T3 line (SVT2) contains four times less vinculin than the parental 3T3 cells, and the rat adenocarcinoma BSp73ASML has no detectable vinculin. Restoration of vinculin in these cells, up to the levels found in 3T3 cells, resulted in an apparent increase in substrate adhesiveness, a decrease in the ability to grow in soft agar, and suppression of their capacity to develop tumors after injection into syngeneic hosts or nude mice. These results suggest that vinculin, a cytoplasmic component of cell-matrix and cell-cell adhesions, may have a major suppressive effect on the transformed phenotype.

scholarly journals Resistance to oncogenic transformation in revertant R1 of human ras-transformed NIH 3T3 cells

1989 ◽  
Vol 9 (5) ◽  
pp. 2258-2263
Author(s):  
N Kuzumaki ◽  
Y Ogiso ◽  
A Oda ◽  
H Fujita ◽  
H Suzuki ◽  
...  
Keyword(s):  
Simian Virus 40 ◽  
Soft Agar ◽  
Simian Virus ◽  
T Antigen ◽  
Oncogenic Transformation ◽  
3T3 Cells ◽  
Cellular Mechanisms ◽  
Ras Gene ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

A flat revertant, R1, was isolated from human activated c-Ha-ras-1 (hu-ac-Ha-ras) gene-transformed NIH 3T3 cells (EJ-NIH 3T3) treated with mutagens. R1 contained unchanged transfected hu-ac-Ha-ras DNA and expressed high levels of hu-ac-Ha-ras-specific mRNA and p21 protein. Transfection experiments revealed that NIH 3T3 cells could be transformed by DNA from R1 cells but R1 cells could not be retransformed by Kirsten sarcoma virus, DNA from EJ-NIH 3T3 cells, hu-ac-Ha-ras, v-src, v-mos, simian virus 40 large T antigen, or polyomavirus middle T antigen. Somatic cell hybridization studies showed that R1 was not retransformed by fusion with NIH 3T3 cells and suppressed anchorage independence of EJ-NIH 3T3 and hu-ac-Ha-ras gene-transformed rat W31 cells in soft agar. These results suggest that the reversion and resistance to several oncogenes in R1 is due not to cellular defects in the production of the transformed phenotype but rather to enhancement of cellular mechanisms that suppress oncogenic transformation.

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