scholarly journals Inositol polyphosphates are not increased by overexpression of Ins(1,4,5)P3 3-kinase but show cell-cycle dependent changes in growth factor-stimulated fibroblasts.

1994 ◽  
Vol 5 (1) ◽  
pp. 17-27 ◽  
Author(s):  
T Balla ◽  
S S Sim ◽  
A J Baukal ◽  
S G Rhee ◽  
K J Catt
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Inositol Polyphosphates ◽  
Transfected Cells ◽  
3T3 Fibroblasts ◽  
Significant Difference ◽  
Early Peak ◽  
Tightly Coupled ◽  
Cycle Dependent ◽  
Nih 3T3

NIH 3T3 fibroblasts were stably transfected with rat brain inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) 3-kinase to explore the relationship between increased production of Ins(1,3,4,5)P4 and the formation of InsP5 and InsP6. Mass measurements of InsP5 and InsP6 revealed no significant difference between kinase- and vector-transfected fibroblasts. However, such 3-kinase-transfected cells, when labeled with [3H]inositol for 48-72 h, showed lower levels of [3H]InsP5 and [3H]InsP6, as well as [3H]Ins(1,3,4,6)P4 and D/L[3H]Ins(1,4,5,6)P4, than their vector-transfected counterparts. Because Ins(1,4,5)P3 3-kinase-transfected cells grew less rapidly than vector-transfected controls, we determined whether the synthesis of InsP5 and InsP6 was related to a specific phase of the cell cycle. When NIH 3T3 cells prelabeled with [3H]inositol were synchronized by serum deprivation followed by stimulation with platelet-derived growth factor (PDGF), the amounts of labeled InsP5 and InsP6 began to increase only after 12 h of stimulation, when cells entered the S-phase as indicated by increased [3H]thymidine incorporation. The enhanced synthesis of these inositol polyphosphates was preceded by an early increase in Ins(1,4,5)P3 and its metabolites that was no longer evident by the fifth hour of PDGF action. There was also a prominent and biphasic increase in the level of D/L-Ins(1,4,5,6)P4 with an early peak at approximately 3 h and a second rise that paralleled the increases in InsP5 and InsP6. These results indicate that the formation of highly phosphorylated inositols is not tightly coupled to the receptor-mediated formation of Ins(1,4,5)P3 and its metabolites but is mainly determined by other factors that operate at specific points of the cell cycle.

scholarly journals A cell cycle and mutational analysis of anchorage-independent growth: cell adhesion and TGF-beta 1 control G1/S transit specifically

1993 ◽  
Vol 122 (2) ◽  
pp. 461-471 ◽  
Author(s):  
EK Han ◽  
TM Guadagno ◽  
SL Dalton ◽  
RK Assoian
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Cell Cycle Progression ◽  
Fibroblast Cell ◽  
Tgf Beta ◽  
Cycle Progression ◽  
Anchorage Independent Growth ◽  
Differential Effects ◽  
3T3 Fibroblasts ◽  
Nih 3T3

We have examined cell cycle control of anchorage-independent growth in nontransformed fibroblasts. In previous studies using G0-synchronized NRK and NIH-3T3 cells, we showed that anchorage-independent growth is regulated by an attachment-dependent transition at G1/S that resembles the START control point in the cell cycle of Saccharomyces cerevisiae. In the studies reported here, we have synchronized NRK and NIH-3T3 fibroblasts immediately after this attachment-dependent transition to determine if other portions of the fibroblast cell cycle are similarly regulated by adhesion. Our results show that S-, G2-, and M-phase progression proceed in the absence of attachment. Thus, we conclude that the adhesion requirement for proliferation of these cells can be explained in terms of the single START-like transition. In related studies, we show that TGF-beta 1 overrides the attachment-dependent transition in NRK and AKR-2B fibroblasts (lines in which TGF-beta 1 induces anchorage-independent growth), but not in NIH-3T3 or Balb/c 3T3 fibroblasts (lines in which TGF-beta 1 fails to induce anchorage-independent growth). These results show that (a) adhesion and TGF-beta 1 can have similar effects in stimulating cell cycle progression from G1 to S and (b) the differential effects of TGF-beta 1 on anchorage-independent growth of various fibroblast lines are directly reflected in the differential effects of the growth factor at G1/S. Finally, we have randomly mutagenized NRK fibroblasts to generate mutant lines that have lost their attachment/TGF-beta 1 requirement for G1/S transit while retaining their normal mitogen requirements for proliferation. These clones, which readily proliferate in mitogen-supplemented soft agar, appear non-transformed in monolayer: they are well spread, nonrefractile, and contact inhibited. The existence of this new fibroblast phenotype demonstrates (a) that the growth factor and adhesion/TGF-beta 1 requirements for cell cycle progression are genetically separable, (b) that the two major control points in the fibroblast cell cycle (G0/G1 and G1/S) are regulated by distinct extracellular signals, and (c) that the genes regulating anchorage-independent growth need not be involved in regulating contact inhibition, focus formation, or growth factor dependence.

scholarly journals Ethanol, Zn2+ and insulin interact as progression factors to enhance DNA synthesis synergistically in the presence of Ca2+ and other cell cycle initiators in fibroblasts

2000 ◽  
Vol 346 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Jin-Sheng HUANG ◽  
Qing-Bai SHE ◽  
Karan S. CRILLY ◽  
Zoltan KISS
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Cell Cycle Progression ◽  
Synergistic Effects ◽  
Dependent Manner ◽  
Cycle Progression ◽  
3T3 Fibroblasts ◽  
Igf I ◽  
Nih 3T3

In serum-starved NIH 3T3 fibroblasts, ethanol (30-80 mM) promoted the effects of insulin and insulin-like growth factor I (IGF-I) on DNA synthesis in a Zn2+-dependent manner. Ethanol and Zn2+ were most effective when added shortly before or after insulin, indicating that all these agents facilitated cell cycle progression. The synergistic effects of ethanol, Zn2+ and insulin (or IGF-I) on DNA synthesis required 1.1-2.3 mM Ca2+, which seemed to act as the cell cycle initiator. When serum-starved cells were pretreated for 2 h with other cell cycle initiators such as 10% (v/v) serum, 50 ng/ml platelet-derived growth factor or 2 ng/ml fibroblast growth factor, subsequent co-treatments with 60 mM ethanol, Zn2+ and insulin for an 18 h period again synergistically increased DNA synthesis. Of the various signal transducing events examined, ethanol stimulated cellular uptake of 45Ca and it enhanced the stimulatory effects of insulin on p70 S6 kinase activity in a Zn2+-dependent manner. In contrast, ethanol inhibited insulin-induced activating phosphorylation of p42/p44 mitogen-activated protein kinases; these inhibitory ethanol effects were prevented by Zn2+. The results show that, in NIH 3T3 fibroblasts, ethanol can promote cell cycle progression in the presence of a cell cycle initiator as well as Zn2+ and insulin (or IGF-I).

scholarly journals FIN13, a novel growth factor-inducible serine-threonine phosphatase which can inhibit cell cycle progression.

1997 ◽  
Vol 17 (9) ◽  
pp. 5485-5498 ◽  
Author(s):  
M A Guthridge ◽  
P Bellosta ◽  
N Tavoloni ◽  
C Basilico
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
Physiological Role ◽  
Cycle Progression ◽  
Transfected Cells ◽  
Inhibit Cell Cycle Progression ◽  
Nih 3T3

We have identified a novel type 2C serine-threonine phosphatase, FIN13, whose expression is induced by fibroblast growth factor 4 and serum in late G1 phase. The protein encoded by FIN13 cDNA includes N- and C-terminal domains with significant homologies to type 2C phosphatases, a domain homologous to collagen, and an acidic domain. FIN13 expression predominates in proliferating tissues. Bacterially expressed FIN13 and FIN13 expressed in mammalian cells exhibit serine-threonine phosphatase activity, which requires Mn2+ and is insensitive to inhibition by okadaic acid. FIN13 is localized in the nuclei of transiently transfected cells. Cotransfection of FIN13-expressing plasmids with a plasmid that expresses the neomycin resistance gene inhibits the growth of drug-resistant colonies in NIH 3T3, HeLa and Rat-1 cells. In transiently transfected cells, FIN13 inhibits DNA synthesis and results in the accumulation of cells in G1 and early S phases. Similarly, the induction of expression of FIN13 under the control of a tetracycline-regulated promoter in NIH 3T3 cells leads to growth inhibition, with accumulation of cells in G1 and early S phases. Thus, overexpression and/or unregulated expression of FIN13 inhibits cell cycle progression, indicating that the physiological role of this phosphatase may be that of regulating the orderly progression of cells through the mitotic cycle by dephosphorylating specific substrates which are important for cell proliferation.

The erbB-2 mitogenic signaling pathway: tyrosine phosphorylation of phospholipase C-gamma and GTPase-activating protein does not correlate with erbB-2 mitogenic potency

1991 ◽  
Vol 11 (4) ◽  
pp. 2040-2048
Author(s):  
F Fazioli ◽  
U H Kim ◽  
S G Rhee ◽  
C J Molloy ◽  
O Segatto ◽  
...  
Keyword(s):  
Growth Factor ◽  
Dna Synthesis ◽  
Phospholipase C ◽  
Signaling Pathway ◽  
Tyrosine Phosphorylation ◽  
Platelet Derived Growth Factor ◽  
Mitogenic Signaling ◽  
Gtpase Activating Protein ◽  
3T3 Fibroblasts ◽  
Nih 3T3

The erbB-2 gene product, gp185erbB-2, unlike the structurally related epidermal growth factor (EGF) receptor (EGFR), exhibits constitutive kinase and transforming activity. We used a chimeric EGFR/erbB-2 expression vector to compare the mitogenic signaling pathway of the erbB-2 kinase with that of the EGFR, at similar levels of expression, in response to EGF stimulation. The EGFR/erbB-2 chimera was significantly more active in inducing DNA synthesis than the EGFR when either was expressed in NIH 3T3 cells. Analysis of biochemical pathways implicated in signal transduction by growth factor receptors indicated that both phospholipase C type gamma (PLC-gamma) and the p21ras GTPase-activating protein (GAP) are substrates for the erbB-2 kinase in NIH 3T3 fibroblasts. However, under conditions in which activation of the erbB-2 kinase induced DNA synthesis at least fivefold more efficiently than the EGFR, the levels of erbB-2- or EGFR-induced tyrosine phosphorylation of PLC-gamma and GAP were comparable. In addition, the stoichiometry of tyrosine phosphorylation of these putative substrates by erbB-2 appeared to be at least an order of magnitude lower than that induced by platelet-derived growth factor receptors at comparable levels of mitogenic potency. Thus, our results indicate that differences in tyrosine phosphorylation of PLC-gamma and GAP do not account for the differences in mitogenic activity of the erbB-2 kinase compared with either the EGFR or platelet-derived growth factor receptor in NIH 3T3 fibroblasts.

scholarly journals Posttranscriptional control of human gamma interferon gene expression in transfected mouse fibroblasts.

1986 ◽  
Vol 6 (6) ◽  
pp. 2253-2256 ◽  
Author(s):  
H A Young ◽  
L Varesio ◽  
P Hwu
Keyword(s):  
Gene Expression ◽  
Genomic Dna ◽  
Gamma Interferon ◽  
Biologically Active ◽  
Posttranscriptional Control ◽  
Transfected Cells ◽  
3T3 Fibroblasts ◽  
Nih 3T3 ◽  
Interferon Gene ◽  
Calcium Phosphate Precipitation

Human gamma interferon genomic DNA was introduced into NIH 3T3 fibroblasts by calcium phosphate precipitation and was not expressed in these cells at the cytoplasmic mRNA or protein level. Treatment of the transfected cells with cycloheximide (1 microgram/ml) induced the accumulation of cytoplasmic gamma interferon mRNA and biologically active human gamma interferon. Analysis of the nuclear enriched RNA from untreated cells indicated that human gamma interferon mRNA was present, suggesting that cycloheximide may act by inhibiting a specific nuclease or may enhance the processing or transport of the RNA from the nucleus to the cytoplasm.

scholarly journals Overexpression of glutamine:fructose-6-phosphate-amidotransferase induces transforming growth factor-β1 synthesis in NIH-3T3 fibroblasts

FEBS Letters ◽  
2001 ◽  
Vol 488 (1-2) ◽  
pp. 95-99 ◽  
Author(s):  
Cora Weigert ◽  
Katrin Brodbeck ◽  
Rainer Lehmann ◽  
Hans U. Häring ◽  
Erwin D. Schleicher
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
3T3 Fibroblasts ◽  
Nih 3T3

scholarly journals The erbB-2 mitogenic signaling pathway: tyrosine phosphorylation of phospholipase C-gamma and GTPase-activating protein does not correlate with erbB-2 mitogenic potency.

1991 ◽  
Vol 11 (4) ◽  
pp. 2040-2048 ◽  
Author(s):  
F Fazioli ◽  
U H Kim ◽  
S G Rhee ◽  
C J Molloy ◽  
O Segatto ◽  
...  
Keyword(s):  
Growth Factor ◽  
Dna Synthesis ◽  
Phospholipase C ◽  
Signaling Pathway ◽  
Tyrosine Phosphorylation ◽  
Platelet Derived Growth Factor ◽  
Mitogenic Signaling ◽  
Gtpase Activating Protein ◽  
3T3 Fibroblasts ◽  
Nih 3T3

The erbB-2 gene product, gp185erbB-2, unlike the structurally related epidermal growth factor (EGF) receptor (EGFR), exhibits constitutive kinase and transforming activity. We used a chimeric EGFR/erbB-2 expression vector to compare the mitogenic signaling pathway of the erbB-2 kinase with that of the EGFR, at similar levels of expression, in response to EGF stimulation. The EGFR/erbB-2 chimera was significantly more active in inducing DNA synthesis than the EGFR when either was expressed in NIH 3T3 cells. Analysis of biochemical pathways implicated in signal transduction by growth factor receptors indicated that both phospholipase C type gamma (PLC-gamma) and the p21ras GTPase-activating protein (GAP) are substrates for the erbB-2 kinase in NIH 3T3 fibroblasts. However, under conditions in which activation of the erbB-2 kinase induced DNA synthesis at least fivefold more efficiently than the EGFR, the levels of erbB-2- or EGFR-induced tyrosine phosphorylation of PLC-gamma and GAP were comparable. In addition, the stoichiometry of tyrosine phosphorylation of these putative substrates by erbB-2 appeared to be at least an order of magnitude lower than that induced by platelet-derived growth factor receptors at comparable levels of mitogenic potency. Thus, our results indicate that differences in tyrosine phosphorylation of PLC-gamma and GAP do not account for the differences in mitogenic activity of the erbB-2 kinase compared with either the EGFR or platelet-derived growth factor receptor in NIH 3T3 fibroblasts.

Posttranscriptional control of human gamma interferon gene expression in transfected mouse fibroblasts

1986 ◽  
Vol 6 (6) ◽  
pp. 2253-2256
Author(s):  
H A Young ◽  
L Varesio ◽  
P Hwu
Keyword(s):  
Gene Expression ◽  
Genomic Dna ◽  
Gamma Interferon ◽  
Biologically Active ◽  
Posttranscriptional Control ◽  
Transfected Cells ◽  
3T3 Fibroblasts ◽  
Nih 3T3 ◽  
Interferon Gene ◽  
Calcium Phosphate Precipitation

Human gamma interferon genomic DNA was introduced into NIH 3T3 fibroblasts by calcium phosphate precipitation and was not expressed in these cells at the cytoplasmic mRNA or protein level. Treatment of the transfected cells with cycloheximide (1 microgram/ml) induced the accumulation of cytoplasmic gamma interferon mRNA and biologically active human gamma interferon. Analysis of the nuclear enriched RNA from untreated cells indicated that human gamma interferon mRNA was present, suggesting that cycloheximide may act by inhibiting a specific nuclease or may enhance the processing or transport of the RNA from the nucleus to the cytoplasm.

scholarly journals Differential processing of colony-stimulating factor 1 precursors encoded by two human cDNAs.

1988 ◽  
Vol 8 (11) ◽  
pp. 5026-5034 ◽  
Author(s):  
C W Rettenmier ◽  
M F Roussel
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Biologically Active ◽  
Colony Stimulating Factor ◽  
Acid Product ◽  
Human Cdna ◽  
3T3 Fibroblasts ◽  
Nih 3T3 ◽  
Stimulating Factor

The biosynthesis of macrophage colony-stimulating factor 1 (CSF-1) was examined in mouse NIH-3T3 fibroblasts transfected with a retroviral vector expressing the 554-amino-acid product of a human 4-kilobase (kb) CSF-1 cDNA. Similar to results previously obtained with a 1.6-kb human cDNA that codes for a 256-amino-acid CSF-1 precursor, the results of the present study showed that NIH-3T3 cells expressing the product of the 4-kb clone produced biologically active human CSF-1 and were transformed by an autocrine mechanism when cotransfected with a vector containing a human c-fms (CSF-1 receptor) cDNA. The 4-kb CSF-1 cDNA product was synthesized as an integral transmembrane glycoprotein that was assembled into disulfide-linked dimers and rapidly underwent proteolytic cleavage to generate a soluble growth factor. Although the smaller CSF-1 precursor specified by the 1.6-kb human cDNA was stably expressed as a membrane-bound glycoprotein at the cell surface and was slowly cleaved to release the extracellular growth factor, the cell-associated product of the 4-kb clone was efficiently processed to the secreted form and was not detected on the plasma membrane. Digestion with glycosidic enzymes indicated that soluble CSF-1 encoded by the 4-kb cDNA contained both asparagine(N)-linked and O-linked carbohydrate chains, whereas the product of the 1.6-kb clone had only N-linked oligosaccharides. Removal of the carbohydrate indicated that the polypeptide chain of the secreted 4-kb cDNA product was longer than that of the corresponding form encoded by the smaller clone. These differences in posttranslational processing may reflect diverse physiological roles for the products of the two CSF-1 precursors in vivo.

Sign in / Sign up

Export Citation Format

Share Document