scholarly journals EFFECT OF ADENOSINE 3'-5'-CYCLIC MONOPHOSPHATE ON CELL PROLIFERATION

1972 ◽  
Vol 55 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Jeffrey E. Froehlich ◽  
Martin Rachmeler
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Dna Synthesis ◽  
Contact Inhibition ◽  
Fresh Medium ◽  
Cyclic Monophosphate ◽  
Human Diploid Fibroblasts ◽  
Dependent Inhibition ◽  
Camp Metabolism ◽  
Inhibition Of Dna Synthesis

Secondary cultures of human diploid fibroblasts, which demonstrate density-dependent inhibition of cell growth, were used to study the effect of adenosine 3'-5'-cyclic monophosphate (cAMP) on cell proliferation. DNA synthesis in nonconfluent cultures and in contact-inhibited cultures stimulated to grow by refeeding with fresh medium was found to be inhibited by exogenous cAMP. The properties of this inhibition of DNA synthesis, together with the alterations in cAMP metabolism observed in confluent cultures of cells stimulated with fresh medium to resume growth, strongly suggest that cAMP is involved in contact-inhibition of cell proliferation.

scholarly journals INHIBITION OF CELL GROWTH IN THE G1 PHASE BY ADENOSINE 3',5'-CYCLIC MONOPHOSPHATE

1974 ◽  
Vol 60 (1) ◽  
pp. 249-257 ◽  
Author(s):  
Jeffrey E. Froehlich ◽  
Martin Rachmeler
Keyword(s):  
Cell Growth ◽  
Dna Synthesis ◽  
Tritiated Thymidine ◽  
S Phase ◽  
Fresh Medium ◽  
G1 Phase ◽  
Cyclic Monophosphate ◽  
Diploid Fibroblasts ◽  
Human Diploid Fibroblasts

Incorporation of tritiated thymidine into acid-precipitable material was used to measure the rate of DNA synthesis in secondary cultures of human diploid fibroblasts. Confluent cultures of human diploid fibroblasts, which are synchronized in the G1 phase due to contact inhibition, were released from growth inhibition either by the addition of fresh medium to the cultures or by trypsinization and replating at nonconfluent densities. Either treatment resulted in a synchronous wave of DNA synthesis beginning 10–15 h after treatment and peaking at 20–25 h. In confluent cultures stimulated by fresh medium, either the addition of 0.25 mM N6, O2-dibutyryl-adenosine 3',5'-cyclic monophosphate (db-cAMP) to the medium in the interval 4–8 h after stimulation or the replacement of the fresh medium in that same 4 h interval with the depleted medium present on the cells for the 2 day period before stimulation delayed the synchronous onset of DNA synthesis in the cultures by about 4 h. In nonconfluent cultures freshly seeded from trypsinized confluent cultures, this same depleted medium obtained after a 2 day incubation of fresh medium on confluent cultures is shown to support the progress of the cells into S phase; however, the addition of 0.25 mM db-cAMP to the medium 3½ h after replating still partially prevented the initiation of DNA synthesis in the cultures. The results are discussed in terms of the role of serum and cAMP in the control of cell growth in fibroblast cultures.

ANF-C-receptor-mediated inhibition of aortic smooth muscle cell proliferation and thymidine kinase activity

1994 ◽  
Vol 266 (1) ◽  
pp. R194-R203 ◽  
Author(s):  
P. A. Cahill ◽  
A. Hassid
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Dna Synthesis ◽  
Thymidine Kinase ◽  
Receptor Binding ◽  
Kinase Activity ◽  
Thymidine Kinase Activity ◽  
Aortic Smooth Muscle ◽  
Inhibition Of Dna Synthesis ◽  
Type Receptor

We have investigated the inhibition of DNA synthesis and cell proliferation by rat atrial natriuretic factor [rANF-(99-126)] and several synthetic peptides that bind selectively to the ANF-C-type clearance receptors in subcultured aortic smooth muscle cells. These peptides decreased serum-induced 1) [3H]thymidine incorporation, 2) cell proliferation, and 3) thymidine kinase activity without altering basal or elevated cAMP or cGMP levels. In contrast, another ANF-C-receptor-binding peptide, des[Gln116,Ser117,Gly118,Leu119,Gly120] rANF-(102-121)-NH2 (cANF), failed to decrease serum-induced mitogenesis, yet 100 nM cANF reversed the inhibition of DNA synthesis and cell proliferation and the decrease of thymidine kinase activity elicited by other C receptor-binding peptides, including rANF-(99-126), rANF-(103-125), and porcine C-type natriuretic peptide [pCNP-(1-22)]. Delayed addition experiments indicated that atrial peptides influence a relatively late event (or events) during the G1 phase of the cell cycle. The inhibition of DNA synthesis by C-receptor-binding atrial peptides appeared to be selective for aortic smooth muscle cells, inasmuch as a potent inhibitory agonist peptide, Cys116-rANF-(102-116), was without significant influence on the incorporation of thymidine in cultured rat mesangial cells or bovine pulmonary artery endothelial cells. These results indicate that atrial natriuretic peptide analogues decrease vascular smooth muscle cell mitogenesis and proliferation by a cyclic nucleotide-independent mechanism involving the C-type receptor. Moreover the inhibition of DNA synthesis by rANF-(99-126) and the neuropeptide pCNP-(1-22) appears to be mediated by the ANF-C-type receptor and is associated with inhibition of thymidine kinase activity.

A Comparison of the Effects of Endotoxin Upon Fibroblast Proliferation and Macromolecular Syntheses

1979 ◽  
Vol 58 (6) ◽  
pp. 1634-1639 ◽  
Author(s):  
R.E. Singer ◽  
W.G. Dutton
Keyword(s):  
Escherichia Coli ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Dna Synthesis ◽  
L929 Cell ◽  
Cell Protein ◽  
Fibroblast Proliferation ◽  
Proline Incorporation ◽  
Inhibition Of Dna Synthesis

The effects of Escherichia coli endotoxin upon mouse L929 cell proliferation, DNA synthesis, protein synthesis, and proline incorporation were determined. It was found that a level of endotoxin which inhibited cell proliferation prompted a similar inhibition of DNA synthesis and overall cell protein synthesis. In contrast, endotoxin was shown to inhibit incorporation of proline into cell protein to a significantly greater extent.

Role of polyamines in glucocorticoid effects on pancreatic acinar AR42J cell growth and differentiation

1992 ◽  
Vol 262 (2) ◽  
pp. G285-G290
Author(s):  
C. D. Logsdon ◽  
F. Alves ◽  
S. Rosewicz
Keyword(s):  
Cell Growth ◽  
Dna Synthesis ◽  
Mrna Levels ◽  
Ar42j Cells ◽  
Glucocorticoid Induction ◽  
Cell Growth And Differentiation ◽  
Ar42j Cell ◽  
Inhibition Of Dna Synthesis ◽  
Stimulation Of

We previously found that glucocorticoids inhibit growth and increase differentiation in rat pancreatic acinar AR42J cells. In the current study, we examined the role of polyamines in these effects. Treatment of AR42J cells with the ornithine decarboxylase (ODC) inhibitor difluoromethylornithine (DFMO) inhibited DNA synthesis. Thus polyamines are required for AR42J cell growth. However, we have previously shown that dexamethasone (Dex) increased AR42J cell ODC activity and mRNA levels. In the current study, we found that Dex treatment increased cellular putrescine levels. These increases in ODC and putrescine occurred during Dex-induced inhibition of DNA synthesis. Therefore, in AR42J cells, ODC activity and polyamine levels are not strictly growth related. To examine the requirement for glucocorticoid induction of ODC activity in glucocorticoid stimulation of differentiation, we examined the effects of DFMO on amylase gene expression and cholecystokinin binding. DFMO reduced cell amylase content while having little effect on mRNA levels in both Dex-treated and untreated cells. In contrast, DFMO had little effect on control CCK binding but inhibited the Dex-induced increase. Thus polyamines are necessary for growth and glucocorticoid-induced differentiation of AR42J cells; however, effects of glucocorticoids on AR42J cell growth and differentiation are not mediated by effects on ODC.

Inhibition of smooth muscle cell growth by nitric oxide and activation of cAMP-dependent protein kinase by cGMP

1994 ◽  
Vol 267 (5) ◽  
pp. C1405-C1413 ◽  
Author(s):  
T. L. Cornwell ◽  
E. Arnold ◽  
N. J. Boerth ◽  
T. M. Lincoln
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Dna Synthesis ◽  
Activity Ratio ◽  
Dependent Protein Kinase ◽  
Inhibition Of Proliferation ◽  
Cyclic Monophosphate ◽  
Dependent Inhibition ◽  
Dependent Protein

Recent studies indicate that nitric oxide (NO) and guanosine 3',5'-cyclic monophosphate (cGMP) may inhibit the proliferation of vascular smooth muscle cells (SMC) in vitro. The purpose of this study was to investigate the mechanism of NO- and cGMP-dependent inhibition of cultured rat aortic SMC. The cytokine interleukin-1 beta (IL-1 beta) inhibited serum- and platelet-derived growth factor-stimulated [3H]thymidine incorporation into DNA in subcultured rat aortic SMC. Incubation with IL-1 beta for 24 h markedly increased cGMP levels but not adenosine 3',5'-cyclic monophosphate (cAMP) levels. However, the IL-1 beta-induced increase in cGMP was correlated with an activation of the cAMP-dependent protein kinase (cAMP kinase) activity ratio. The activation of the cAMP kinase was prevented by treatments that blocked NO and cGMP production. The NO-generating vasodilator, S-nitroso-N-acetylpenicillamine (SNAP) also inhibited DNA synthesis and elevated cGMP levels. The inhibition of DNA synthesis by both IL-1 beta and SNAP was observed only when cGMP levels were elevated to high levels (10-fold or more). As was the case for IL-1 beta, SNAP increased the activity ratio of cAMP kinase. Selective inhibition of cAMP kinase using (R)-p-bromoadenosine 3',5'-cyclic monophosphorothioate prevented the inhibition of proliferation by IL-1 beta. By contrast, the inhibitor of the cGMP-dependent protein kinase, (R)-p-bromoguanosine 3',5'-cyclic monophosphorothioate, had no effect on IL-1 beta-induced inhibition of cellular proliferation. These studies suggest that cGMP-dependent activation of the cAMP kinase may be responsible in part at least for the NO-dependent inhibition of proliferation of subcultured rat aortic SMC.

scholarly journals Inhibition of DNA synthesis in SV3T3 cultures by isolated 3T3 plasma membranes.

1983 ◽  
Vol 97 (1) ◽  
pp. 276-279 ◽  
Author(s):  
S W Peterson ◽  
V Lerch
Keyword(s):  
Plasma Membrane ◽  
Dna Synthesis ◽  
Cell Cultures ◽  
Plasma Membranes ◽  
Inhibitory Effect ◽  
Density Dependent ◽  
Inhibition Of Growth ◽  
Dependent Inhibition ◽  
Membrane Components ◽  
Inhibition Of Dna Synthesis

3T3 plasma membranes were added to subconfluent cultures of SV3T3 cells in the presence of fusogens. If this protocol results in the introduction into the SV3T3 cell membrane of 3T3 plasma membrane components responsible for density-dependent inhibition of growth, then the SV3T3 cell cultures would be expected to show decreased rates of DNA synthesis as they approach confluence. Results of these experiments indicate that rates of DNA synthesis in SV3T3 cultures so treated were as much as 63% less than in untreated controls. This effect could not be attributed to the fusogens or to the 3T3 plasma membranes alone. This growth-inhibitory effect is specific for 3T3 membranes and is not observed when SV3T3 plasma membranes are fused with SV3T3 cell cultures. These data support the hypothesis that one aspect of the loss of density-dependent inhibition of growth in SV3T3 cells is a deletion or alteration in plasma membrane components and, further, that density-dependent inhibition of growth can be in part restored to SV3T3 cell cultures by fusing the cells with 3T3 plasma membranes.

Polyamine-modulated expression of c-myc plays a critical role in stimulation of normal intestinal epithelial cell proliferation

2005 ◽  
Vol 288 (1) ◽  
pp. C89-C99 ◽  
Author(s):  
Lan Liu ◽  
Li Li ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Huifang M. Zhang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Epithelial Cell ◽  
Dna Synthesis ◽  
Intestinal Epithelial Cell ◽  
Small Intestinal Mucosa ◽  
Intestinal Epithelial ◽  
Epithelial Cell Proliferation ◽  
Myc Gene ◽  
Stimulation Of

The nuclear protein c-Myc is a transcription factor involved in the control of cell cycle. Our previous studies indicated that cellular polyamines are absolutely required for cell proliferation in crypts of small intestinal mucosa and that polyamines have the ability to stimulate expression of the c- myc gene. The current study went further to determine whether induced nuclear c-Myc plays a role in stimulation of cell proliferation by polyamines in intestinal crypt cells (IEC-6 line). Exposure of normal quiescent cells after 24-h serum deprivation to 5% dialyzed fetal bovine serum (dFBS) increased both cellular polyamines and expression of the c- myc gene. Increased c-Myc protein formed heterodimers with its binding partner, Max, and specifically bound to the Myc/Max binding site, which was associated with an increase in DNA synthesis. Depletion of cellular polyamines by pretreatment with α-difluoromethylornithine (DFMO) prevented increases in c- myc expression and DNA synthesis induced by 5% dFBS. c- Myc gene transcription and cell proliferation decreased in polyamine-deficient cells, whereas the natural polyamine spermidine given together with DFMO maintained c- myc gene expression and cell growth at normal levels. Disruption of c- myc expression using specific c- myc antisense oligomers not only inhibited normal cell growth (without DFMO) but also prevented the restoration of cell proliferation by spermidine in polyamine-deficient cells. Ectopic expression of wild-type c- myc by recombinant adenoviral vector containing c- myc cDNA increased cell growth. These results indicate that polyamine-induced nuclear c-Myc interacts with Max, binds to the specific DNA sequence, and plays an important role in stimulation of normal intestinal epithelial cell proliferation.

Sign in / Sign up

Export Citation Format

Share Document