scholarly journals Sorting out of normal and virus-transformed cells in cellular aggregates.

1976 ◽  
Vol 68 (2) ◽  
pp. 276-286 ◽  
Author(s):  
H Gershman ◽  
J Drumm ◽  
L Culp
Keyword(s):  
B Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Con A ◽  
Adhesive Properties ◽  
Established Cell ◽  
Swiss 3T3 ◽  
Cellular Aggregates

The sorting-out behavior (self-segregation of two cell types from mixtures of the two) of five different established cell lines was studied. Eight of the ten possible binary combinations of these lines, cultured as cellular aggregates, were examined. Mouse BALB/c 3T3 cells sorted out internally to the corresponding malignant SV40 virus-transformed 3T3 cells. The transformed 3T3 line (SVT-2) did not sort out from a revertant line selected from SVT-2 cells by resistance to concanavalin A (con A). The revertant cells sorted out externally to the parent BALB/c 3T3 cells, although segregation was generally incomplete. BALB/c 3T3 cells did not sort out from another contact-inhibited line of 3T3 cells derived from Swiss albino mice (Swiss 3T3). Both BALB/c 3T3 and Swiss 3T3 cells sorted out from cells of the contact-inhibited hamster line, NIL B. Instead of a two-layered sphere, however, a three-layered structure was observed with most of the NIL B cells external to the 3T3 cells, and a few NIL B cells comprising the center of the sphere. On the other hand, NIL B cells did not consistently sort out from either the SVT-2 or con A cells. In general, sorting out between pairs of these five lines are slower and less complete than is generally observed between the more extensively studied chick embryonic tissue cells, suggesting that the cultured cells may be more closely related in their adhesive properties. The internal segregation of BALB/c 3T3 cells relative to SVT-2 cells is consistent with the hypothesis that transformed cells are less adhesive than their nontransformed counterparts.

CCK-B receptors produce similar signals but have opposite growth effects in CHO and Swiss 3T3 cells

1997 ◽  
Vol 273 (5) ◽  
pp. C1449-C1457 ◽  
Author(s):  
Katharina Detjen ◽  
David Yule ◽  
Min-Jen Tseng ◽  
John A. Williams ◽  
Craig D. Logsdon
Keyword(s):  
B Cells ◽  
Dna Synthesis ◽  
Cell Types ◽  
Receptor Activation ◽  
Receptor Expression ◽  
Growth Responses ◽  
3T3 Cells ◽  
Growth Effects ◽  
Receptor Coupling ◽  
Swiss 3T3

Rat cholecystokinin-B (CCK-B) receptors were transfected into Chinese hamster ovary (CHO)-K1 (CHO-CCK-B) and Swiss 3T3 (Swiss 3T3-CCK-B) cells, and the effects of receptor activation on cell proliferation and intracellular signaling were investigated. CCK octapeptide (CCK-8) treatment had no effect on cell growth in quiescent CHO-CCK-B cells but inhibited DNA synthesis, proliferation, and colony formation when the cells were grown in fetal bovine serum (FBS). In contrast, CCK-8 stimulated DNA synthesis in quiescent Swiss 3T3-CCK-B cells and had no effect when the cells were grown in FBS. These differences in growth responses were not due to differences in the level of receptor expression, as similar numbers of receptors were present in both cell types. To determine whether the different growth effects were due to differences in receptor coupling to common second messenger pathways, we investigated the effects of CCK-8 on several known intracellular signals. In both cell types, CCK-8 stimulated increases in intracellular Ca2+concentration and polyphosphoinositide hydrolysis with similar potencies and efficacies. CCK-8 also stimulated arachidonate release from both cell types, although the potency was higher in the CHO cells. Adenosine 3′,5′-cyclic monophosphate generation was observed at high agonist concentrations in both cell types and was much greater in cells with higher receptor density. In summary, receptor activation had opposite effects on growth parameters in CHO and Swiss 3T3 cells, but only minor differences were observed in the characteristics of CCK-B receptor coupling to specific second messengers in the two cell types. Thus cellular context is a principal determinant of the biological effects of CCK-B receptor activation, and differences in biological responses may occur independently of major differences in receptor coupling.

Differential activation of focal adhesion kinase, Rho and Rac by the ninth and tenth FIII domains of fibronectin

1999 ◽  
Vol 112 (17) ◽  
pp. 2937-2946
Author(s):  
N.A. Hotchin ◽  
A.G. Kidd ◽  
H. Altroff ◽  
H.J. Mardon
Keyword(s):  
Growth Factor ◽  
Focal Adhesion Kinase ◽  
Signaling Pathways ◽  
Focal Adhesion ◽  
Cell Attachment ◽  
Cell Types ◽  
Integrin Receptors ◽  
3T3 Cells ◽  
Swiss 3T3 ◽  
Kinase Phosphorylation

Fibronectins are widely expressed extracellular matrix ligands that are essential for many biological processes. Fibronectin-induced signaling pathways are elicited in diverse cell types when specific integrin receptors bind to the ninth and tenth FIII domains, FIII9-10. Integrin-mediated signal transduction involves activation of signaling pathways of the growth factor-dependent Ras-related small GTP-binding proteins Rho and Rac, and phosphorylation of focal adhesion kinase. We have dissected the requirement of FIII9 and FIII10 for Rho and Rac activity and phosphorylation of focal adhesion kinase in BHK fibroblasts and Swiss 3T3 cells. We demonstrate that FIII10 supports cell attachment but does not induce phosphorylation of focal adhesion kinase. In Swiss 3T3 cells, growth factor-independent phosphorylation of focal adhesion kinase and downstream adhesion events are dependent upon the presence of FIII9 in the intact FIII9-10 pair, whereas FIII10-mediated focal adhesion kinase phosphorylation requires a synergistic signal from growth factors. Furthermore, FIII10 is able to elicit cellular responses mediated by Rho, but not Rac, whereas FIII9-10 can elicit both Rho- and Rac-mediated responses. We propose that activation of specific integrin subunits by the FIII10 and FIII9-10 ligands elicits distinct signaling events. This may represent a general molecular mechanism for activation of receptor-specific signaling pathways by a multi-domain ligand.

scholarly journals Production of plasminogen activator by established cell lines of mouse origin.

1977 ◽  
Vol 73 (1) ◽  
pp. 47-55 ◽  
Author(s):  
D B Rifkin ◽  
R Pollack
Keyword(s):  
Plasminogen Activator ◽  
Cell Lines ◽  
3T3 Cells ◽  
Established Cell Lines ◽  
Embryo Cultures ◽  
Established Cell ◽  
Swiss 3T3 ◽  
Swiss 3T3 Cell ◽  
Transformed Cell Lines ◽  
3T3 Cell Lines

The correlation between malignant transformation and increased plasminogen activator synthesis has been studied in a variety of established cell lines. In contrast to the behavior of secondary mouse embryo cultures, which always show increased fibrinolytic activity when transformed, no such correlation was found within the BALB/c 3T3 line and its transformed derivatives. Cell lines were established from tumors initiated in BALB/c mice by several transformed cell lines. These lines were generally found to contain no more plasminogen activator than the cells used for inoculation. A correlation was found between transformation and plasminogen activator synthesis within Swiss 3T3 cell lines. However, the correlation was not maintained by serum revertants of transformed Swiss 3T3 cells.

scholarly journals Differential Modulation and Subsequent Blockade of Mitogenic Signaling and Cell Cycle Progression by Pasteurella multocida Toxin

2000 ◽  
Vol 68 (8) ◽  
pp. 4531-4538 ◽  
Author(s):  
Brenda A. Wilson ◽  
Lyaylya R. Aminova ◽  
Virgilio G. Ponferrada ◽  
Mengfei Ho
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Pasteurella Multocida ◽  
Morphological Changes ◽  
Cell Types ◽  
Vero Cells ◽  
3T3 Cells ◽  
Mitogenic Response ◽  
Cycle Progression ◽  
Swiss 3T3

ABSTRACT The intracellularly acting protein toxin of Pasteurella multocida (PMT) causes numerous effects in cells, including activation of inositol 1,4,5-trisphosphate (IP3) signaling, Ca2+ mobilization, protein phosphorylation, morphological changes, and DNA synthesis. The direct intracellular target of PMT responsible for activation of the IP3 pathway is the Gq/11α-protein, which stimulates phospholipase C (PLC) β1. The relationship between PMT-mediated activation of the Gq/11-PLC-IP3pathway and its ability to promote mitogenesis and cellular proliferation is not clear. PMT stimulation of p42/p44 mitogen-activated protein kinase occurs upstream via Gq/11-dependent transactivation of the epidermal growth factor receptor. We have further characterized the effects of PMT on the downstream mitogenic response and cell cycle progression in Swiss 3T3 and Vero cells. PMT treatment caused dramatic morphological changes in both cell lines. In Vero cells, limited multinucleation, nuclear fragmentation, and disruption of cytokinesis were also observed; however, a strong mitogenic response occurred only with Swiss 3T3 cells. Significantly, this mitogenic response was not sustained. Cell cycle analysis revealed that after the initial mitogenic response to PMT, both cell types subsequently arrested primarily in G1and became unresponsive to further PMT treatment. In Swiss 3T3 cells, PMT induced up-regulation of c-Myc; cyclins D1, D2, D3, and E; p21; PCNA; and the Rb proteins, p107 and p130. In Vero cells, PMT failed to up-regulate PCNA and cyclins D3 and E. We also found that the initial PMT-mediated up-regulation of several of these signaling proteins was not sustained, supporting the subsequent cell cycle arrest. The consequences of PMT entry thus depend on the differential regulation of signaling pathways within different cell types.

scholarly journals Quantitative analysis of intercellular adhesive specificity in freshly explanted and cultured cells.

1981 ◽  
Vol 90 (1) ◽  
pp. 55-62 ◽  
Author(s):  
F Sieber ◽  
S Roseman
Keyword(s):  
Quantitative Analysis ◽  
Cho Cells ◽  
Binomial Distribution ◽  
Cultured Cells ◽  
Chinese Hamster ◽  
Simian Virus 40 ◽  
Cell Types ◽  
Simian Virus ◽  
Fluorescent Label ◽  
3T3 Cells

A new method is presented for the quantitative analysis of intercellular adhesive specificity. In this assay, two cell types are mixed, one unlabeled and the other labeled with the fluorescent dye, fluorescamine [4-phenylspiro(feran-2[3H],1'-phthalan)-3,3'-dione]. The resulting aggregates are analyzed by fluorescence microscopy to determine the number of labeled and unlabeled cells per aggregate. Random (nonspecific) aggregation was characterized by a binomial distribution, and adhesive specificity was accordingly quantified by the deviation (as determined by a chi-square test) from the calculated binomial distribution. The labeling procedure was simple and rapid, and experiments with 18 different cell types showed that it did not affect cell viability, morphology, rate and extent of adhesion, plating efficiency, and the capability of myogenic cells to undergo terminal differentiation. Most important, assays with morphologically identifiable cell pairs indicated that the fluorescent label neither induced apparent nor destroyed existing adhesive specificity. The most pronounced adhesive specificities were observed with freshly explanted cells from adult tissues and also with mixtures of simian virus 40-transformed and nontransformed BALB/c 3T3 cells. A glucosamine-6-phosphate N-acetylase-deficient mutant 3T3 line (AD6), however, aggregated randomly with parental 3T3 cells. Lectin-resistant mutant Chinese hamster ovary (CHO) cells displayed marginal adhesive specificity when mixed with normal CHO cells.

Control of cell mobility by cyclic AMP

1984 ◽  
Vol 65 (1) ◽  
pp. 177-192
Author(s):  
W.E. Katzin ◽  
H. Gershman
Keyword(s):  
B Cells ◽  
Chick Embryo ◽  
Cyclic Amp ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cell Types ◽  
Intracellular Concentration ◽  
Dibutyryl Cyclic Amp ◽  
3T3 Cells ◽  
Cell Mobility

Cyclic AMP concentrations have been measured in a number of different cell types under a variety of culture conditions in an attempt to define the relationship between the endogenous concentration of cyclic AMP and cell mobility. In previous work it was shown that agents that increase the intracellular concentration of cyclic AMP can effectively suppress cell movement. In Balb/c 3T3 cells, which have a very low mobility in cellular aggregates, the intracellular concentration of cyclic AMP was elevated only transiently soon after the formation of the three-dimensional cell masses. In contrast, in the highly mobile virally transformed counterpart of Balb/c 3T3 cells, called SVT-2, the concentration of cyclic AMP was relatively low soon after the cell masses were formed, but later rose to a level that was higher than that in Balb/c 3T3 cells. Using NIL B cells, SV40-transformed NIL B cells, and several lines of tumour cells derived from NIL B cells, it was found that the average intracellular concentration of cyclic AMP did not vary significantly from one population of cells to another. Finally, the intracellular concentration of cyclic AMP was measured in chick embryo ventricle cells. The mobility of these cells had previously been found to decrease as embryonic development progressed; furthermore, it had been shown that dibutyryl cyclic AMP plus theophylline produced nearly complete inhibition of their movement in cell masses. In the series of experiments reported here we found that the endogenous concentration of cyclic AMP in aggregates and fragments of chick embryo ventricle cells decreases as development proceeds; these data are consistent with preliminary experiments reported by other investigators. In a separate set of experiments, the intracellular concentration of cyclic AMP was measured in cells that had been cultured in a medium containing 1.2 mM-dibutyryl cyclic AMP plus 1.0 mM-theophylline. This drug treatment has previously been shown to inhibit the movement of cells both in aggregates and in monolayers; it also produces striking effects on cell shape and ultrastructure. In aggregates of chick embryo ventricle cells, treatment with these drugs resulted in increases in the intracellular concentrations of cyclic AMP from approximately 10 picomol/mg protein to approximately 500 picomol/mg protein. In Balb/c 3T3 and SVT-2 cells this treatment increased cyclic AMP concentrations from 3.7 to 160 and from 6.4 to 470 picomol/mg protein, respectively.

Signalling Pathways Involved in the Mitogenic Effects of cAMP

1997 ◽  
Vol 92 (5) ◽  
pp. 445-451 ◽  
Author(s):  
D. J. Withers
Keyword(s):  
Dna Synthesis ◽  
Mapk Pathway ◽  
Critical Role ◽  
Cell Types ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
3T3 Cells ◽  
Mitogen Activated Protein ◽  
Swiss 3T3

1. Elevation of intracellular cyclic AMP (cAMP) is a potent mitogenic signal for a number of cell types, including Swiss 3T3 cells, thyroid epithelial cells and the somatotroph cells of the anterior pituitary. 2. Activation of the mitogen-activated protein kinase (MAPK) cascade has been shown to underlie the mitogenic effects of many growth factors. However, the precise relationship between the mitogenic effects of cAMP and the MAPK cascade is not fully defined. 3. In Swiss 3T3 cells, elevation of cAMP did not stimulate kinases at all three levels of the MAPK cascade. Additionally, blockade of the MAPK pathway failed to inhibit cAMP-stimulated DNA synthesis. 4. Mitogenic combinations of cAMP strongly stimulated the phosphorylation and activation of the serine/threonine kinase p70 S6 kinase, p70S6K, an effect that was inhibited by rapamycin. This agent markedly inhibited cAMP-stimulated DNA synthesis, suggesting a critical role for p70S6K in cAMP mitogenic signalling. 5. Thus, multiple parallel but distinct signalling pathways may be involved in the action of mitogens. This redundancy has important implications for the pathogenesis and treatment of conditions characterized by inappropriate activation of growth factor signalling pathways.

scholarly journals Cytoskeleton organization is aberrantly rearranged in the cells of B chronic lymphocytic leukemia and hairy cell leukemia

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 233-239 ◽  
Author(s):  
F Caligaris-Cappio ◽  
L Bergui ◽  
L Tesio ◽  
G Corbascio ◽  
F Tousco ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Hairy Cell Leukemia ◽  
Close Contact ◽  
Cell Types ◽  
Lymphocytic Leukemia ◽  
Hairy Cell ◽  
Cell Leukemia ◽  
Adhesive Properties

Abstract The organization of actin-containing microfilaments and vimentin- containing intermediate filaments has been investigated in B chronic lymphocytic leukemia (B-CLL), hairy cell leukemia (HCL), and normal B cells cultured in vitro under basal conditions and after induction with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). In uninduced B-CLL cells, F-actin was predominantly associated with dot-shaped structures scattered over the ventral membrane representing spotty close contact adhesion sites analogous to ““podosomes” described in other cell types. On TPA induction, podosomes became clustered in sharply defined areas sitting in the cell center beneath the nucleus. In some cells, long actin-containing protrusions appeared. In HCL cells, F-actin was associated with thin microvilli responsible for the “hairy” appearance; occasional cells showed scattered podosomes. On TPA induction, HCL cells sprouted long dendritic processes rich in submembraneous F-actin, which made intertwined networks. Therefore, in both B-CLL and HCL cells, adhesion structures were present and the capacity for adhesion in vitro was marked, which might explain some peculiar clinical features of the diseases. Adhesion structures and adhesive properties never appeared in normal B cells. These data further support the notion that B-CLL and HCL, although clinically different, may share common biological features and suggest that in these disorders, cytoskeleton modifications may represent a hallmark of transformation.

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.

scholarly journals DIBUTYRYL CYCLIC ADENOSINE 3' 5' MONOPHOSPHATE, SUGAR TRANSPORT, AND REGULATORY CONTROL OF CELL DIVISION IN NORMAL AND TRANSFORMED CELLS

1973 ◽  
Vol 56 (2) ◽  
pp. 487-491 ◽  
Author(s):  
William J. Grimes ◽  
Judith L. Schroeder
Keyword(s):  
Cell Division ◽  
Cell Growth ◽  
Sugar Transport ◽  
Cell Number ◽  
High Density ◽  
Regulatory Control ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Lower Ability ◽  
Swiss 3T3

Swiss 3T3 cells exhibit contact-regulated cell growth and have a lower ability to transport 2-deoxyglucose than polyoma (Py)-transformed 3T3 cells. Py3T3 cells treated with dibutyryl cyclic adenosine 3'5' monophosphate (dBcAMP) and theophylline have reduced cell growth and transport 2-deoxyglucose at the same rate as normal 3T3 cells. Evidence that the cessation of cell growth and reduced transport abilities in Py3T3 cells does not represent a return to contact-regulated growth comes from the following observations. First, treating high density Py3T3 cells with dBcAMP allows more than two doublings of cell number, even though ability to transport 2-deoxyglucose is returned to levels equal to those of normal 3T3 cells. Second, dBcAMP prevents serum-stimulated increases in 2-deoxyglucose transport in Py3T3 but not in 3T3 cells.

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