共查询到20条相似文献,搜索用时 125 毫秒
1.
Ruo-Pan Huang Hisako Muramatsu Takashi Muramatsu 《Development, growth & differentiation》1990,32(2):189-195
MK gene was intensely expressed, when aggregates of HM-1 embryonal carcinoma (EC) cells were treated with retinoic acid for 2 days to induce the differntiation to nerve cells, myoblasts and extraembryonic endoderm cells. The conditions inhibiting nerve cell diffrentiation or extraembryonic endoderm cell differentiation affected MK gene expression only slightly. The maximum level of MK RNA was detected 2 days after initiation of retionic acid treatment, when cells were morphologically indistinguishable from undifferentiated EC cells. Thus, MK gene appears to be expressed in differentiating EC cells irrespective of the direction of differentiation. The degree of MK gene expression in sparsely cultured HM-1 cells correlated with the concentration of retinoic acid, especially between 10-8 and 10-7 M. When retinoic acid treatment was terminated after 1 day, the amount of MK RNA started to decrease. These two results are consistent with the view that retionic acid complexed with the receptor is directly involved in expression of MK gene. 相似文献
2.
Stimulation of differentiation of several murine embryonal carcinoma cell lines by retinoic acid 总被引:16,自引:0,他引:16
Retinoic acid stimulates several murine embryonal carcinoma (EC) cell lines, even those previously considered to be incapable of differentiating, to give rise to cell types distinguishable from the parental phenotype in morphology, production of plasminogen activator and surface protein properties. Retinoic acid promotes these changes over a range of low concentrations (10−9–10−5 M) which are generally non-toxic to the cells. The effects are clearly demonstrated when EC cells are aggregated prior to exposure to retinoic acid. It is concluded that the observed phenotypic alterations induced by retinoic acid reflect differentiation of the EC cells since non-EC cell characteristics are maintained by cloned cells several generations after retinoic acid is removed from the cultures. Our studies suggest that although retinoic acid stimulates the conversion of EC cells to differentiated derivatives, it does not influence the direction of differentiation. Furthermore, the effectiveness of retinoic acid in stimulating differentiation of EC cells from lines such as Nulli-SCC1 raises the question of whether true ‘nullipotent’ EC lines really exist. 相似文献
3.
Monique Cadrin Geoffrey O. Wasteneys Elizabeth M. V. Jones-Villeneuve David L. Brown Kenneth R. Reuhl 《Cell biology and toxicology》1988,4(1):61-80
Immunofluorescence staining with antibodies to tubulin, neurofilaments and glial filaments was used to study the effects of methylmercury on the differentiation of retinoic acid-induced embryonal carcinoma cells into neurons and astroglia and on the cytoskeleton of these neuroectodermal derivatives. Methylmercury did not prevent undifferentiated embryonal carcinoma cells from developing into neurons and glia. Treatment of committed embryonal carcinoma cells with methylmercury doses exceeding 1 M resulted in the formation of neurons with abnormal morphologies. In differentiated cultures, microtubules were the first cytoskeletal element to be affected. Their disassembly was time- and concentration-dependent. Microtubules in glial cells and in neuronal perikarya were more sensitive than those in neuronal processes. Neurofilaments and glial filaments appeared relatively insensitive to methylmercury treatment but showed reorganization after complete disassembly of the microtubules. The data demonstrate 1) the sensitivity of microtubules of both neurons and glia to methylmercury-induced depolymerization, and 2) the heterogeneous response of neuronalAbbreviations -MEM
alpha minimal essential medium
- EC
embryonal carcinoma cells
- FCS
fetal calf serum
- MAP
microtubule-associated protein
- MeHg
methylmercury
- RA
retinoic acid 相似文献
4.
Teratocarcinoma cells exhibit growth cooperativity in vitro 总被引:1,自引:0,他引:1
Malignant PC13 embryonal carcinoma (EC) cells differentiate in vitro in response to retinoic acid, giving rise to a population of benign endoderm-like cells (END), termed PC13 END. PC13 EC and PC13 END cells exhibit growth cooperativity in co-culture, whereby the EC cells stimulate END cell proliferation and the END cells can support EC cell multiplication. The EC cells' stimulatory effect operates via soluble, diffusible factors which are also active on a range of fibroblast cell lines. END cells support the multiplication of EC cells plated at low density, via a multifactorial mechanism. Contact-dependent effects can operate in the absence of END cell metabolic activity, while contact-independent effects require the continuous presence of live END cells. It was observed that there was a variation in the ability of fibroblast cell lines to act as EC cell feeders. Similar interactive events may be important during the in vivo proliferation and differentiation of teratocarcinoma cells and their embryonic counterparts. 相似文献
5.
We have studied the expression of c-src and c-abl proto-oncogenes in early mouse development using embryonal carcinoma (EC) cells as a model system, and compared this to the expression pattern in adult tissues. In all three EC lines tested (F9, PC13, and P19), c-src and c-abl mRNA can be detected. When F9 and PC13 are induced to differentiate they form endodermal cells characteristic of the early embryo, and we found no change in c-src or c-abl expression. In contrast, P19 cells showed increased levels of both mRNAs both mRNAs when induced to differentiate along the neural pathway by retinoic acid, whereas differentiation along the muscle pathway by dimethyl sulfoxide resulted in decreased levels of c-abl expression. These results are consistent with the idea that c-src and c-abl have important functions in the differentiation of the cell types of the later embryo, but not in those of the early embryo. 相似文献
6.
R. Atencia M. García-Sanz G. Pérez-Yarza A. Asumendi E. Hilario J. Aréchaga 《Protoplasma》1997,198(3-4):163-169
Summary During the execution phase of apoptosis, the cell undergoes a set of morphological changes which reveal the activation of a complex machinery leading the cell to its disruption into small, spherical, membrane-bounded fragments called apoptotic bodies. In the present study, we have focused on the implications of the micro-filament network in the early stages of the active phase of apoptosis. By using confocal microscopy, we have analysed the location of the actin microfilaments and two actin-binding proteins, -actinin and myosin, in F9 embryonal carcinoma cells undergoing apoptosis during the stages previous to their fragmentation. Our results show that these proteins locate in the centre of the disrupting cell and form a three-dimensional structure which suggests the existence of a fully functional contractile system involved in the fragmentation of the cell and the formation of apoptotic bodies.Abbreviations CI-II
calpain inhibitor II
- CD
cytochalasin D
- CSLM
confocal scanning laser microscopy
- EC
embryonal carcinoma
- FALS
forward angle side scattered
- FCS
fetal calf serum
- FITC
fluorescein isothyocyanate
- ISS
integrated side scattered
- PBS
phosphate buffered saline: PI propidium iodide
- RA
retinoic acid
- TEM
transmission electron microscopy 相似文献
7.
8.
We document the time of appearance and the levels of two markers of differentiation during the formation of embryoid bodies by two embryonal carcinoma (EC) cell lines. Neither of these markers has been described before for EC cells differentiating in aggregate culture, and they further extend the identification and characterization of new cell types. Both F9 and PC13 EC cell lines form embryoid bodies (so-called because they resemble early mouse embryos) with an outer epithelial layer of visceral endoderm cells, after suspension culture in the presence of retinoic acid. However, the two cell lines differ in the procedures needed to initiate the differentiation process. Once floating aggregate cultures have been formed, the time course of the appearance of epidermal growth factor (EGF) receptors and of the secretion of transferrin are similar in both cell lines, although the levels differ. EGF receptors and transferrin are quantified by 125I-EGF binding assays and enzyme-linked immunosorbent assays (ELISA) using specific antibodies, respectively. The expression of EGF receptors increases about two fold while that of transferrin increases up to 40 fold after treating F9 aggregates with retinoic acid. The EGF receptors reach a maximum 4 days after adding retinoic acid and then decline, while transferrin only increases later from a low but detectable level. For PC13 cells, EGF receptors increase tenfold, and transferrin synthetic rate increases 40 fold during the time-course. Interestingly, unstimulated F9 cells in monolayer cultures also express low levels of these markers, while the levels in PC13 EC cells are barely detectable above background.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Metabolism of retinoids by embryonal carcinoma cells 总被引:4,自引:0,他引:4
Several embryonal carcinoma (EC) cell lines were tested in culture for their ability to metabolize all-trans-[3H]retinol, all-trans-[3H]retinyl acetate, and all-trans-[3H]retinoic acid. There was little, if any, metabolism of all-trans-retinol to more polar compounds; we failed to detect conversion to acidic retinoids by reverse-phase high performance liquid chromatography and derivatization. We also did not observe [3H]retinoic acid when EC cells were incubated with [3H]retinyl acetate. Unlike the other retinoids, all-trans-[3H]retinoic acid, even at micromolar levels, was almost totally modified by cells from several EC lines within 24 h. Most of the labeled products were secreted into the medium. Some EC lines metabolized retinoic acid constitutively, whereas others had an inducible enzyme system. A differentiation-defective line, which contains little or no cellular retinoic acid-binding protein activity, metabolized retinoic acid poorly, even after exposure to inducers. At least eight retinoic acid metabolites were generated; many contain hydroxyl residues. Our data lead us to propose that retinol does not induce differentiation of EC cells in vitro via conversion to retinoic acid. Also, the relatively rapid metabolism of retinoic acid by EC cells suggests either that the induction of differentiation need involve only a transient exposure to this retinoid or that one or more of the retinoic acid metabolites can also promote differentiation. 相似文献
10.
C.L. Mummery C.E. van den Brink P.T. van der Saag S.W. de Laat 《Developmental biology》1984,104(2):297-307
Time-lapse films were made of PC13 embryonal carcinoma cells, synchronized by mitotic shake off, in the absence and presence of retinoic acid. Using a method based on the transition probability model, cell cycle parameters were determined during the first five generations following synchronization. In undifferentiated cells, cell cycle parameters remained identical for the first four generations, the generation time being 11–12 hr. In differentiating cells, with retinoic acid added at the beginning of the first cycle, the first two generations were the same as controls. The duration of the third generation, however, was increased to 15.7 hr while the fourth and fifth generation were approximately 20 hr, the same as in exponentially growing, fully differentiated cells. The increase in generation time of dividing cells was principally due to an increase in the length of S phase. Cell death induced by retinoic acid also occurred principally in the third and subsequent generations. Cell population growth was then significantly less than that expected from the generation time derived from cycle analysis of dividing cells. Cells lysed frequently as sister pairs suggesting susceptibility to retinoic acid toxicity determined in a generation prior to death. Morphological differentiation, as estimated by the area of substrate occupied by cells, was shown to begin in the second cell cycle after retinoic acid addition. These results demonstrate that as in the early mammalian embryo, differentiation of embryonal carcinoma cells to an endoderm-like cell is also accompanied by a decrease in growth rate but that this is preceded by acquisition of the morphology characteristic of the differentiated progeny. 相似文献
11.
In an initial effort to determine whether circulating retinol might promote differentiation of embryonal carcinoma (EC) cells in tumor form, we have assessed the ability of retinol to stimulate differentiation of cultured EC cells. We found that retinol induces several murine EC cell lines to differentiate in vitro. Differentiated derivatives were distinguishable from parental EC cells by morphology, cell surface antigenic properties and levels of secretion of plasminogen activator. Retinol effects could be seen at concentrations as low as 8.7 × 10−8 M (0.025 (μg/ml). Only two of eight EC lines tested failed to differentiate in response to retinol: PCC4-azaIR, which dies at retinol concentrations above 3.5 × 10−7 M; and PCC4(RA)-1, a mutant line derived from PCC4-azaIR cells, which also fails to differentiate in response to retinoic acid. 相似文献
12.
Cell cycle analysis during retinoic acid induced differentiation of a human embryonal carcinoma-derived cell line 总被引:1,自引:0,他引:1
C L Mummery M A van Rooijen S E van den Brink S W de Laat 《Cell differentiation》1987,20(2-3):153-160
Several subclones of the human embryonal carcinoma (EC) cell line Tera-2 can be induced to differentiate in monolayer culture by retinoic acid (RA) to a flattened cell type with reduced growth rate. Using a method based on the transition probability model, we have analysed changes in cell cycle kinetics of Tera-2 cells during the differentiation process. Growth inhibition was shown to occur without a lag period and to be partly due to an increase in the duration of the S-phase, but with a relatively greater contribution from an increase in the duration of G1-phase. Since the fraction of the cell population in the G1-phase then doubled, cells accumulated in this part of the cycle. In contrast, the reduced proliferation rate of two murine EC cell lines, PC13 and P19, treated with RA occurs after a lag period of about two cell cycles and is mainly attributable to an increase in the duration of the S-phase. The results illustrate a differential response of human and murine EC cells to growth regulation by RA and again emphasize that although the stem cells of murine teratocarcinomas may provide a useful model, they are not identical to their human counterparts. 相似文献
13.
14.
N. E. Haidar M. Carrara C. Andriamampandry J. N. Kanfer L. Freysz H. Dreyfus R. Massarelli 《Neurochemical research》1994,19(1):9-13
Human neuroblastoma cholinergic LA-N-2 cells were used as an experimental model to test the possibility that the methylation of phosphoethanolamine (PEtn) to phosphocholine (PCho) and free choline (Cho) (Andriamampandry et al. 1989) could contribute to acetylcholine (AcCho) synthesis. LA-N-2 cells were incubated with [3H]Cho for 90 min and 22.7% of the radioactivity was present in PCho, 18.5% in free Cho and 4.8% as AcCho. The ratio of Cho/AcCho, however, was of about 1 after 16 hours of incubation. The incorporation of 10M [3H]ethanolamine (Etn) into MeEtn, PMeEtn, PMe2Etn and their corresponding phospholipids was reduced in cells incubated in medium containing 7.2M choline as compared to cells incubated in medium devoid of choline indicating that the lack of Cho from the incubation medium stimulated the conversion of PEtn to Cho water soluble derivatives. Incubation of LA-N-2 cells with [3H]Etn led to the labelling of [3H]AcCho. Cultures incubated in parallel with [3H]Cho showed that roughly 10% of [3H]AcCho obtained after 16 hrs of incubation with the Cho label derived from [3H]Etn. The synthesis of Cho and AcCho from Etn may be enhanced after cellular differentiation induced by the growth of the cells in the presence of retinoic acid (RA). The results indicate that the methylation of [3H]Etn and/or of [3H]PEtn may be used by cholinergic neurons as precursor for AcCho.Abbreviations Etn
ethanolamine
- MeEtn
monomethylethanolamine
- Me2Etn
dimethylethanolamine
- P-
phosphoryl
- AcCho
acetylcholine
- Ptd
phosphatidyl
- LPtd
lysophosphatidyl
- RA
retinoic acid 相似文献
15.
HGPRT+ and HGPRT? clones have been isolated from the mouse embryonal carcinoma tissue culture line PC13. Upon inoculation into isogeneic mice, all clones form tumors showing the same pattern of differentiation as that given by PC13, namely, a predominance of neural differentiation with the presence of smaller amounts of other tissues. The karyotype of one HGPRT clone, PC13TG8, has been compared with that of PC13 by G-banding. Both lines possess a marker isochromosome and show a substantial degree of chromosome imbalance. By two techniques, (a) autoradiography after [3H]hypoxanthine labelling and (b) co-culture in toxic purine analogues, PC13 and PC13TG8 cells have been shown to participate in metabolic co-operation with each other and with the Chinese hamster cell line Don and its derivatives. Like other tissue culture lines, however, they show little or no metabolic co-operation with derivatives of mouse L cells. 相似文献
16.
Previously it was observed that mixture cultures of “nullipotent” and pluripotent embryonal carcinoma (EC) cells failed to differentiate, suggesting that nullipotent cells might restrict the differentiation of pluripotent cells (M. J. Rosenstraus and A. J. Levine, 1979, Cell17, 337–346). This report shows, however, that the differentiation of mixed cultures is dependent on the relative growth rates of the two cell types and that nullipotent cells do not directly affect pluripotent cell development. When the growth rate of nullipotent cells was modulated by taking advantage of drug-resistance markers, mixed cultures, containing pluripotent PSA-1 cells and a genetically marked subclone of nullipotent F9 cells, exhibited extensive differentiation. The differentiated cells were PSA-1 derivatives, whereas, the F9 cells remained as undifferentiated EC cells. Similar results were obtained when a genetically marked PSA-1 subclone was cocultured with a second nullipotent cell line, Nulli SSC1. Thus nullipotent and pluripotent EC cells appear to express their developmental potential autonomously in mixed cultures. This implies that the nullipotent cell lines studied are intrinsically incapable of responding to the conditions that trigger in vitro differentiation of EC cells upon aggregation. 相似文献
17.
Mesophyll cells isolated from Zinnia elegans L. cv. Canary Bird were cultured for 96 h in a liquid medium containing 0.1 mg l-1 -naphthaleneacetic acid and 1 mg l-1 benzyladenine in which both differentiation of tracheary elements (TE) and cell division were induced, or in a medium containing 0.1 mg l-1 -naphthaleneacetic acid and 0.001 mg l-1 benzyladenine, in which cell division was induced but TE differentiation was not. Lignification was found to occur only in the former medium, fairly synchronously after 76 h of culture, 5 h later than the onset of visible secondary wall thickening. Changes in the soluble phenolics were not correlated with TE differentiation. Of three important enzymes which have been reported to play a role in TE differentiation, the activity of phenylalanine ammonia-lyase (EC 4.3.1.5) in the TE-inductive culture was higher than that in the control culture between 72 and 96 h of culture, when TE differentiation progressed and lignin was synthesized actively. O-Methyltransferase (EC 2.1.1.6) activity was higher in the control culture than in the TE-inductive culture, indicating that this enzyme was not a marker enzyme of TE differentiation. The activities of peroxidases (EC 1.11.1.7), one extractable and the other nonextractable, with CaCl2 from the cell walls, reached peaks at 72 h (just before lignification) and 84 h of culture (active lignin synthesis), respectively, in the TE-inductive culture only, whereas the activity of soluble peroxidase showed a similar pattern of increase in the TE-inductive to the control culture. These results indicate that phenylalanine ammonia-lyase and peroxidase bound to the cell walls can be marker proteins for the differentiation of TE.Abbreviations OMT
O-methyltransferase
- PO
peroxidase
- PAL
phenylalanine ammonia-lyase
- TE
tracheary element(s) 相似文献
18.
19.
The differentiation of teratocarcinoma stem cells is marked by the types of collagen which are synthesized. 总被引:9,自引:0,他引:9
A cloned line of undifferentiated teratocarcinoma cells (OC15S1) was either maintained as a homogeneous embryonal carcinoma (EC) cell population or was cultured under conditions where the cells differentiated into endoderm-like (END) cells. In this study we examine the synthesis of collagen in both EC and END cells. Cell cultures were incubated with tritiated proline and lysine, and the radioactive collagen secreted into the medium was extracted and purified or immunoprecipitated by antibodies to type IV collagen (Adamson and Ayers, 1979). Radioactive collagens were identified by electrophoretic mobility, by sensitivity to collagenase and to reduction, by insensitivity to pepsin, by cyanogen bromide peptides, and by aminoacid analyses of 3-hydroxyproline, 4-hydroxyproline and proline. OC15S1 EC cells were found to synthesize several collagenous polypeptides, of which 60–70% of the radioactivity was like that of basement membrane (type IV) collagen. Type I-like collagen was the main collagenous product of END cells, but a minor product of EC cells. We concluded that type IV collagen synthesis was suppressed during the differentiation of EC cells to END, while type I-like synthesis was increased. Similarly, other EC cell lines produced mainly type IV-like collagen polypeptides (PC13, F9, PSA1), and following the formation of END cells, two lines produced mainly type I-like collagen polypeptides (PC13, C145b). The type of endoderm formed on embryoid bodies, however, presents an alternate route of differentiation, since immunoperoxidase tests showed that it was synthesizing significant amounts of type IV collagen. We discuss the significance of these findings in relation to a similar change which occurs during normal development. 相似文献
20.
Sjerp M. Weima Marga A. van Rooijen Alie Feijen Christine L. Mummery Everardus J.J. van Zoelen Siegfried W. de Laat Adriana J.M. van den Eijnden-van Raaij 《Differentiation; research in biological diversity》1989,41(3):245-253
The human embryonal carcinoma cell lines Tera-2 clone 13 and NTera-2 clone D1 can be induced by retinoic acid to differentiate in vitro into neuroectodermal derivatives. The undifferentiated cells are rapidly proliferating and tumorigenic, whereas retinoic-acid-treated cells possess a decreased growth rate, lose their transformed phenotype and show a finite lifespan. Differentiation is accompanied by a marked increase in the levels of mRNA for TGF-beta 1 and TGF-beta 2 and the production of TGF-beta activity. Just like murine embryonal carcinoma cells the growth of Tera-2 clone 13 cells is not affected by the addition of either TGF-beta 1 or TGF-beta 2 to the culture medium. In contrast to published data on murine embryonal carcinoma cells, Tera-2 clone 13 and NTera-2 clone D1 cells bind TGF-beta 1 with high affinity, which is due to the presence of type-III TGF-beta receptors. Furthermore, and again in contrast to murine embryonal carcinoma cells, treatment of the human embryonal carcinoma cells with retinoic acid causes a nearly complete loss of TGF-beta 1 binding sites. These results are discussed in the light of similarities and differences in the regulation of growth and differentiation of human and murine embryonal carcinoma cell lines. 相似文献