epidermal-growth-factor and Teratoma

Topics: Animals; Antigens, Surface; Cell Adhesion Molecules; Cell Differentiation; Embryo, Mammalian; Embryo, Nonmammalian; Embryonic and Fetal Development; Epidermal Growth Factor; Female; Growth Substances; Oncogenes; Platelet-Derived Growth Factor; Pregnancy; Somatomedins; Teratoma

Topics: Animals; Cell Differentiation; Epidermal Growth Factor; ErbB Receptors; Extraembryonic Membranes; Female; Fetus; Growth Substances; Mice; Models, Biological; Oncogenes; Placenta; Pregnancy; Receptors, Transferrin; Teratoma; Transferrin

EGF-Rs are cell membrane glycoproteins of wide distribution. They have not yet been fully characterized or purified but are probably molecules of 170-190,000 mol. wt. in most cells. The growth factor EGF binds and will saturate cell surface receptors with a KA of about 5 X 10(9) M-1 although a receptor class with an affinity in excess of 10(10) M-1 has been detected in some cells. The number of receptors on a cell does not determine the level of its response. Some cell types have receptors which bind EGF, but with no mitogenic response. The ways in which receptor affinity and/or number is modulated are described. This and other evidence is reviewed in a search for a suitable model of a mechanism of action on the cell, which best fits the current data. There is ample evidence that EGF binds to the receptor; that ligand-receptor complexes cluster or aggregate; and then are internalized and degraded, but evidence for a direct connection between internalization and the subsequent mitogenic response is lacking. Good correlations between internalization and mitogenic responses have been observed and developed into a theory of endocytic activation, but there is a body of evidence which cannot be accommodated by this theory. Instead, an alternative model is suggested.

Topics: Animals; Binding Sites; Cell Membrane; Cell Transformation, Neoplastic; Cell Transformation, Viral; DNA; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Kinetics; Models, Biological; Molecular Weight; Organ Specificity; Peptides; Pregnancy; Receptors, Cell Surface; Species Specificity; Teratoma; Tissue Distribution; Tretinoin

The availability of induced pluripotent stem cells (iPSCs) has created extraordinary opportunities for modeling and perhaps treating human disease. However, all reprogramming protocols used to date involve the use of products of animal origin. Here, we set out to develop a protocol to generate and maintain human iPSC that would be entirely devoid of xenobiotics. We first developed a xeno-free cell culture media that supported the long-term propagation of human embryonic stem cells (hESCs) to a similar extent as conventional media containing animal origin products or commercially available xeno-free medium. We also derived primary cultures of human dermal fibroblasts under strict xeno-free conditions (XF-HFF), and we show that they can be used as both the cell source for iPSC generation as well as autologous feeder cells to support their growth. We also replaced other reagents of animal origin (trypsin, gelatin, matrigel) with their recombinant equivalents. Finally, we used vesicular stomatitis virus G-pseudotyped retroviral particles expressing a polycistronic construct encoding Oct4, Sox2, Klf4, and GFP to reprogram XF-HFF cells under xeno-free conditions. A total of 10 xeno-free human iPSC lines were generated, which could be continuously passaged in xeno-free conditions and maintained characteristics indistinguishable from hESCs, including colony morphology and growth behavior, expression of pluripotency-associated markers, and pluripotent differentiation ability in vitro and in teratoma assays. Overall, the results presented here demonstrate that human iPSCs can be generated and maintained under strict xeno-free conditions and provide a path to good manufacturing practice (GMP) applicability that should facilitate the clinical translation of iPSC-based therapies.

Topics: Animals; Biomarkers; Cell Culture Techniques; Cell Proliferation; Cell Transdifferentiation; Cells, Cultured; Cellular Reprogramming; Culture Media; Epidermal Growth Factor; Fibroblasts; Gene Expression Regulation, Developmental; GPI-Linked Proteins; Homeodomain Proteins; Humans; Induced Pluripotent Stem Cells; Intercellular Signaling Peptides and Proteins; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Male; Membrane Glycoproteins; Mice; Mice, SCID; Nanog Homeobox Protein; Neoplasm Proteins; Octamer Transcription Factor-3; Recombinant Proteins; SOXB1 Transcription Factors; Teratoma; Transduction, Genetic

Previous studies have shown that prolonged propagation of undifferentiated human embryonic stem cells (hESCs) requires conditioned medium from mouse embryonic feeders (MEF-CM) as well as matrix components. Because hESCs express growth factor receptors, including those for basic fibroblast growth factor (bFGF), stem cell factor (SCF), and fetal liver tyrosine kinase-3 ligand (Flt3L), we evaluated these and other growth factors for their ability to maintain undifferentiated hESCs in the absence of conditioned medium. We found cultures maintained in bFGF alone or in combination with other factors showed characteristics similar to MEF-CM control cultures, including morphology, surface marker and transcription factor expression, telomerase activity, differentiation, and karyotypic stability. In contrast, cells in media containing Flt-3L, thrombopoietin, and SCF, individually or in combination, showed almost complete differentiation after 6 weeks in culture. These data demonstrate that hESCs can be maintained in nonconditioned medium using growth factors.

Topics: Animals; Antigens, CD; Antigens, Surface; Cell Differentiation; Cell Line; Cell Proliferation; Cell Survival; Culture Media, Conditioned; DNA-Binding Proteins; Embryo, Mammalian; Epidermal Growth Factor; Fibroblast Growth Factor 2; Flow Cytometry; Gene Expression; Glycoproteins; Glycosphingolipids; GPI-Linked Proteins; Humans; Intercellular Signaling Peptides and Proteins; Karyotyping; Membrane Glycoproteins; Mice; Mice, SCID; Neoplasm Proteins; Octamer Transcription Factor-3; Pluripotent Stem Cells; Proteoglycans; Stage-Specific Embryonic Antigens; Telomerase; Teratoma; Tetraspanin 29; Transcription Factors

Embryonic stem (ES) cells have been suggested as candidate therapeutic tools for cell replacement therapy in neurodegenerative disorders. However, limitations for the use of these cells lie in our restricted knowledge of the molecular mechanisms involved in their specialized differentiation and in the risk of tumor formation. Recent findings suggest that the EGF-CFC protein Cripto is a key player in the signaling pathways controlling neural induction in ES cells. Here we show that in vitro differentiation of Cripto(-/-) ES cells results in increased dopaminergic differentiation and that, upon transplantation into Parkinsonian rats, they result in behavioral and anatomical recovery with no tumor formation. The use of knockout ES cells that can generate dopamine cells while eliminating tumor risk holds enormous potential for cell replacement therapy in Parkinson's disease.

Topics: Animals; Brain; Brain Neoplasms; Cell Differentiation; Dopamine; Embryo, Mammalian; Epidermal Growth Factor; Male; Oxidopamine; Parkinson Disease; Rats; Rats, Sprague-Dawley; Stem Cell Transplantation; Stem Cells; Stereotyped Behavior; Teratoma

The expression of mRNA for the epidermal growth factor (EGF) receptor, EGF and transforming growth factor alpha (TGF-alpha) was determined in 76 malignant, six borderline and 15 benign primary ovarian tumours using the reverse transcriptase-polymerase chain reaction and related to clinical and pathological parameters. Of the malignant tumours, 70% (53/76) expressed EGF receptor mRNA, 31% (23/75) expressed EGF mRNA and 35% (26/75) expressed TGF-alpha mRNA. For the borderline tumours, four of six (67%) expressed EGF receptor mRNA, 1/6 (17%) expressed TGF-alpha mRNA and none expressed EGF mRNA. Finally, 33% (5/15) of the benign tumours expressed EGF receptor mRNA, whereas 40% (6/15) expressed EGF mRNA and 7% (1/15) expressed TGF-alpha mRNA. The presence of the EGF receptor in malignant tumours was associated with that of TGF-alpha (P = 0.0015) but not with EGF (P = 1.00), whereas there was no relationship between the presence of EGF and TGF-alpha (P = 1.00). EGF receptor mRNA expression was significantly and positively associated with serous histology (P = 0.006) but not with stage or grade. Neither EGF nor TGF-alpha showed any link with histological subtype or stage. The survival of patients with malignant tumours possessing EGF receptor mRNA was significantly reduced compared with that of patients whose tumours were negative (P = 0.030 for all malignant tumours; P = 0.007 for malignant epithelial tumours only). In contrast, neither the expression of TGF-alpha nor EGF was related to survival. These data suggest that the presence of EGF receptor mRNA is associated with poor prognosis in primary ovarian cancer.

Topics: Base Sequence; Carcinoma; DNA Primers; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Humans; Molecular Sequence Data; Multivariate Analysis; Ovarian Neoplasms; Prognosis; RNA, Messenger; RNA, Neoplasm; Survival Analysis; Teratoma; Tumor Necrosis Factor-alpha

The function of growth factors in early development is reviewed. Special emphasis is on the epidermal growth factor and its receptor, and on the c-fos and its family of transcriptional factor proteins, which play an important role in modulating the growth and differentiation of early embryos and embryonal carcinoma cells.

Topics: Animals; Blastocyst; Cell Differentiation; Embryonal Carcinoma Stem Cells; Epidermal Growth Factor; ErbB Receptors; Genes, jun; Mice; Neoplastic Stem Cells; Proto-Oncogene Proteins c-fos; Signal Transduction; Teratoma

1246-3A is an insulin-independent tumorigenic cell line isolated from the C3H mouse teratoma-derived adipogenic cell line 1246. In the present paper, we have demonstrated that testosterone inhibits the in vivo tumorigenic properties of the 1246-3A cells. Castrated male mice receiving injections of 1246-3A cells developed larger tumors at a higher frequency than sham-operated animals. Administration of testosterone to castrated male mice resulted in a dramatic decrease in tumor development. In vitro studies indicated that testosterone inhibited by 50% the proliferation of the 1246-3A cells in culture. However, growth inhibition was observed only if the cells had been cultivated in the presence of testosterone for at least 4 days. In contrast, testosterone had little effect on the proliferation of the parent cell line 1246. Binding of several polypeptide growth factors was examined in cells cultivated in the absence and in the presence of testosterone. Testosterone increased 125I-EGF specific binding to 1246-3A cells. Scatchard analysis of EGF binding indicated that testosterone treatment induced a 2.4-fold increase in the number of cell surface EGF binding sites. This was accompanied by an increase in the intensity of cross-linked EGF receptors on the cells treated with testosterone. In addition, 1246-3A cells cultivated for 9 days in the presence of testosterone displayed a 10-fold increase in the level of EGF receptor mRNA when compared to 1246-3A cells maintained in its absence. Similar to its action on cell proliferation, the increase in EGF receptor number and mRNA expression was observed mainly if 1246-3A cells had been exposed to testosterone for 9 days. The data presented in this paper demonstrate that both in vivo and in vitro, testosterone induces in the teratoma-derived 1246-3A cell line phenotypic changes such as growth inhibition and modulation of EGF receptor expression.

Topics: Animals; Cell Division; Cell Line; Epidermal Growth Factor; ErbB Receptors; Insulin; Kinetics; Male; Mice; Mice, Inbred C3H; Orchiectomy; Radioligand Assay; Receptor, Insulin; RNA, Messenger; Teratoma; Testosterone; Transcription, Genetic; Tumor Cells, Cultured

The human teratocarcinoma cell line PA-1 was derived from culturing ascites fluid cells from a patient with an ovarian germ line tumor. We previously described a non-neoplastic variant cloned from the PA-1 human teratocarcinoma cell line, clone 6, which at passage 40 was resistant to transformation by activated ras oncogenes. However, these cells could be transformed by a plasmid containing both myc and ras. Another PA-1 cell variant, clone 1, isolated at passage 63 and used 50 passages later becomes tumorigenic in nude mice after transfection with an activated ras oncogene (Tainsky et al., Anticancer Res., 8, 899-914, 1988). We report here that the progression from ras resistance to ras susceptibility occurs in both clone 1 and clone 6 cells during 25 passages in culture. In the presence of epidermal growth factor, transforming growth factor-alpha, and basic fibroblast growth factor, the ras-transformable cells exhibit anchorage independent growth, whereas the ras-resistant cells can not be growth stimulated by these growth factors. Similarly, ornithine decarboxylase (ODC) activity was inducible in ras susceptible and ras transformed cells by these growth factors, but not in the ras resistant cells. These differences are not due to the level and activity of epidermal growth factor receptor or to the level of expression of 25 proto-oncogenes.

Topics: Blotting, Northern; Cell Line; Cell Transformation, Neoplastic; Clone Cells; Enzyme Induction; Epidermal Growth Factor; ErbB Receptors; Fibroblast Growth Factor 2; Genes, ras; Humans; Immunoblotting; Oncogenes; Ornithine Decarboxylase; Plasmids; Protein-Tyrosine Kinases; Proto-Oncogene Proteins p21(ras); Receptors, Cell Surface; Receptors, Fibroblast Growth Factor; Signal Transduction; Teratoma

Embryonal carcinoma (EC) cells are the malignant stem cells of teratocarcinoma and have the capacity to proliferate in the absence of serum growth factors. As yet no receptor protein tyrosine kinases have been identified on undifferentiated EC cells and as a consequence tyrosine kinase signaling pathways could not be studied in these cells. We have used stably transfected P19 embryonal carcinoma cells expressing a well-characterized receptor protein tyrosine kinase, the human epidermal growth factor receptor (hEGF-R) to study protein tyrosine kinase signaling mechanisms in undifferentiated EC cells. Here we report that the ectopically expressed hEGF-R contains EGF-inducible autophosphorylation activity and is rapidly internalized and degraded upon ligand binding. In addition, the exogenous hEGF-R confers EGF-responsiveness to these cells in that inositol phosphate formation and cytoplasmic-free Ca2+ concentration are enhanced in response to EGF. Furthermore, the Na+/H+ exchanger is activated in response to EGF, leading to a sustained rise in intracellular pH. Our results show that undifferentiated P19 EC cells contain the necessary components of protein tyrosine kinase signal transduction machinery.

Topics: Adenosine Triphosphate; Animals; Bradykinin; Calcium; Cell Line; Chlorides; Epidermal Growth Factor; ErbB Receptors; Histamine; Humans; Hydrogen-Ion Concentration; Inositol Phosphates; Kinetics; Lithium; Lithium Chloride; Mice; Phosphorylation; Protein-Tyrosine Kinases; Signal Transduction; Teratoma; Transfection

The mouse C3H teratoma-derived cell line 1246 is an adipogenic cell line which stringently requires insulin to proliferate and differentiate in defined medium. From this cell line an insulin-independent cell line called 1246-3A was isolated. It was found that, in contrast to 1246 cells, 1246-3A cells had lost the ability to differentiate and became tumorigenic when injected at a density of 10(6) cells/mouse into syngeneic host C3H mice. In addition, they produce in their culture medium transforming growth factor alpha- and beta-like polypeptides which stimulate their proliferation. Highly tumorigenic insulin-independent cell lines able to give rise to tumor when injected at a density of 10(4) cells/mouse were isolated by using an in vitro-in vivo shuttle technique. The highly tumorigenic cell lines have lost the response to TGF-beta 1. The binding of TGF-beta 1 to the nontumorigenic parent cell line or to cells displaying increased tumorigenic properties was investigated. The data presented here indicate that the increased tumorigenicity is accompanied by a progressive decrease of specific binding of TGF-beta 1 to the cells. However, the decreased number of cell surface TGF-beta 1 binding sites in the highly tumorigenic cells did not correlate with an increase in the secretion of TGF-beta protein by the tumorigenic cells, as all of TGF-beta produced by the cells was in a latent form. Affinity cross-linking experiments indicated that the 1246 cell line displayed several TGF-beta cross-linked molecular species (MW 140, 92, and 70 kDa). Increase of tumorigenicity was accompanied by a marked decrease in the intensity of the cross-linked bands, particularly of the 92 and 70 kDa species.

Topics: Animals; Cell Differentiation; Cell Division; Cell Line; Epidermal Growth Factor; Insulin; Kinetics; Mice; Mice, Inbred C3H; Molecular Weight; Receptors, Cell Surface; Receptors, Transforming Growth Factor beta; Teratoma; Transforming Growth Factor beta

To identify polypeptide growth factors for human teratocarcinoma cells, we studied the malignant ovarian teratoma-derived cell line, PA-1, that grew autonomously in serum-free medium. Medium conditioned by undifferentiated PA-1 cells strongly stimulated proliferation of the mouse mammary tumor cell line, GR 2H6, which is responsive to epidermal growth factor (EGF) and insulinlike growth factor-I (IGF-I). After ammonium sulfate precipitation, PA-1 conditioned medium was analyzed by anion exchange chromatography and bioassay of elution fractions on GR 2H6 cells that were grown in medium deficient in either EGF or insulin. The results demonstrated that PA-1 CM contained factors that can substitute for EGF and IGF-I in stimulating growth of GR 2H6 cells. Western blots of peak mitogenic fractions revealed low molecular weight polypeptides that were immunoreactive with either anti-EGF or anti-IGF-I antibodies. Indirect immunofluorescence staining of PA-1 cells with monoclonal antibodies localized receptors for each growth factor, and binding of human EGF and IGF-I to these cells was quantified by radioreceptor assays. Secretion of factors closely related to EGF and IGF-I by PA-1 cells under serum-free conditions may provide a novel model system to study molecular mechanisms of autocrine growth stimulation in teratocarcinomas.

Topics: Animals; Antibodies; Blotting, Western; Child; Chromatography, Ion Exchange; Culture Media; Epidermal Growth Factor; ErbB Receptors; Female; Fluorescent Antibody Technique; Humans; Insulin-Like Growth Factor I; Mammary Neoplasms, Experimental; Mice; Ovarian Neoplasms; Peptides; Receptors, Cell Surface; Receptors, Somatomedin; Teratoma; Tumor Cells, Cultured

A hybrid clone was developed by the fusion of a pluripotent mouse teratocarcinoma cell line PCC-4 AzaR to the Zajdela ascitic hepatoma (ZAH) of rat origin. This hybrid cell line, F2231A, possessed a predominantly teratocarcinoma morphology with a large nucleus and prominent nucleoli, and grew in nests. F2231A cells formed undifferentiated tumours in irradiated Sv/129 mice. It formed aggregates when subcultured at high densities in bacteriological Petri dishes. The hybrid cell line differentiated in response to retinoic acid and also underwent spontaneous differentiation upon overgrowth. Karyological analysis showed the presence of several rat chromosomes in the hybrid and upon isozyme analysis it was found that only the rat variant of the X-linked enzyme HGPRT was expressed. Analysis of the genomic DNA with a cloned probe, specific for rat repetitive sequences, gave strong positive signals in the hepatoma parent and F2231A cells while the parental embryonal carcinoma (EC) cells were negative. The hybrid cell line, like the PCC-4 cells, expressed the SSEA-1 surface marker but not SSEA-3, intercellular fibronectin and EGF receptors. Upon differentiation of F2231A cells there was a loss of expression of SSEA-1. The mRNA for alpha-fetoprotein was expressed by the hybrid cell line and in this respect it resembled the hepatoma parent. Albumin mRNA was not detectable in the hybrid cell line. The mRNA for the transformation-related protein, p53, was expressed at a high level in F2231A cells. The hybrid cell line F2231A retained several of the biochemical and immunological properties of the teratocarcinoma cells.

Topics: Animals; Antigens, Surface; Blotting, Southern; Cell Differentiation; DNA, Neoplasm; Epidermal Growth Factor; Hybrid Cells; Isoenzymes; Karyotyping; L-Lactate Dehydrogenase; Liver Neoplasms, Experimental; Mice; Molecular Weight; Phenotype; Rats; Repetitive Sequences, Nucleic Acid; RNA; Stem Cells; Teratoma; Tretinoin; Tumor Cells, Cultured

A novel human gene, encoding a 188 amino acid polypeptide that contains a region similar to that of the epidermal growth factor, has been isolated. The gene, expressed in undifferentiated human and mouse teratocarcinoma cells, is shut off after inducing the cells to differentiate by treatment with retinoic acid. Introduction of the cDNA under the control of a viral LTR induces transformation of NIH3T3 cells.

Topics: Amino Acid Sequence; Animals; Base Sequence; Blotting, Northern; Cell Differentiation; Cell Line; Cells, Cultured; DNA, Neoplasm; Epidermal Growth Factor; Genes; Humans; Mice; Molecular Sequence Data; Multigene Family; Sequence Homology, Nucleic Acid; Teratoma; Transcription, Genetic; Tretinoin

The rate at which P19 embryonal carcinoma cells in monolayer culture become anchorage dependent during differentiation induced by retinoic acid (RA) was investigated. In both nonsynchronized cultures and cultures synchronized by mitotic selection, the ability to grow in semisolid medium, characteristic of the malignant stem cell, decreased after a lag period of about 12 hr in the continuous presence of RA, prior to an increase in cell generation time. However, striking differences between synchronized and nonsynchronized cultures were observed in their commitment to differentiation following RA removal. After only 2 hr of exposure to RA, synchronized cells continued a program of differentiation in which they became anchorage dependent, while at least 24 hr of exposure was required for exponentially growing cells to become similarly committed. Induction of anchorage dependence by RA was also strikingly cell cycle dependent; 2 or 4 hr of exposure of synchronized cells to RA in G1 phase, when the intrinsic capacity for soft agar growth is low, was sufficient to commit cells to anchorage dependence, but a similar exposure in S phase was not. Together, these results suggested that interactions between cells in different cell cycle phases in asynchronous cultures influenced commitment since exposure to RA for more than one cycle (13 hr) was required for all cells to become anchorage dependent. Increased plasminogen activator secretion and epidermal growth factor binding, markers of certain differentiated cell types, increased only 3 and 5 days after RA addition, respectively, and were not induced by pulsed exposure to RA of less than 24 hr, even in synchronized cells.

Topics: Animals; Antibodies, Monoclonal; Cell Adhesion; Cell Cycle; Cell Differentiation; Cell Line; Culture Media; Cytoskeleton; Epidermal Growth Factor; ErbB Receptors; Glycolipids; Laminin; Lewis X Antigen; Mice; Plasminogen Activators; Teratoma; Time Factors; Tretinoin

Aggregation of pluripotent P19 embryonal carcinoma (EC) cells in the presence of DMSO induces differentiation to various mesodermal cell types, including spontaneously contracting muscle. We have established clonal cell lines from these cultures and characterized one (MES-1) in particular for its response to growth factors. In contrast to the undifferentiated stem cells, but as a number of myoblast and muscle cell lines, MES-1 cells respond to both carbachol and bradykinin by the rapid release of Ca2+ from intracellular stores. In addition, MES-1 express receptors for and respond mitogenically to epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). Isolated membranes from these cells retain the capacity to bind both ligands; addition of EGF to membranes induces endogenous phosphorylation of several proteins, including the EGF receptor itself and a 38 kD protein, while addition of PDGF specifically induces phosphorylation of the PDGF receptor. By contrast, other derivatives of P19, isolated from retinoic acid (RA)-treated aggregates and resembling neuroectodermal or endodermal cell types respond only to EGF; PDGF neither binds nor induces phosphorylation and a mitogenic response in these cells. During differentiation from EC cells therefore MES-1 cells developed a combination of growth factor receptor characteristics typical of somatic mesodermal cells and indicate that such receptors on EC-derived mesodermal cells are also functional.

Topics: Animals; Bradykinin; Carbachol; Cells, Cultured; Epidermal Growth Factor; ErbB Receptors; Mesoderm; Mice; Phosphorylation; Platelet-Derived Growth Factor; Receptors, Cell Surface; Receptors, Platelet-Derived Growth Factor; Teratoma

It has been shown that differentiated derivatives of retinoic acid (RA)-treated F9 embryonal carcinoma cells become non-malignant. In the present study it is asked whether this loss of malignancy is due to cellular differentiation. Because the ability of cells to grow in suspension correlates with in vivo tumorigenicity, we determined the time course of the loss of this property, after RA treatment, with relation to the differentiation to parietal endoderm and the acquisition of normalcy in several common transformation-specific properties of F9 cells. Our results show that pretreatment with RA for 24 h caused 80% inhibition of anchorage-independent growth in F9 cells, and this inhibition reached its highest level (98%) after pretreatment with RA for 48 h and longer. However, all other observed transformation-related properties, and the levels of plasminogen activator (marker for parietal endoderm) remained unaltered at this early post-treatment stage. These observations suggest that the loss of malignancy is a relatively early event in the biochemical pathways involved in the RA-induced differentiation of F9 cells. Furthermore, our data show that the presence of elevated levels of p53 alone may not be sufficient to maintain the anchorage-independent growth and the rapid proliferation of F9 cells.

Topics: Actins; Animals; Bucladesine; Cell Adhesion; Cell Differentiation; Cell Division; Cell Line; Cell Transformation, Neoplastic; Deoxyglucose; Embryonal Carcinoma Stem Cells; Epidermal Growth Factor; ErbB Receptors; Fibronectins; Mice; Neoplasm Proteins; Neoplastic Stem Cells; Phosphoproteins; Plasminogen Activators; Receptors, Cell Surface; Teratoma; Tretinoin; Tumor Suppressor Protein p53

Differentiated clonal cell lines were isolated from pluripotent P19 embryonal carcinoma (EC) cells treated as aggregates with retinoic acid. Two were characterized in detail. The lines differ in morphology, proliferation rate, the production of plasminogen activator, and in their mitogenic response to insulin but both produce extracellular matrix proteins and can be serially passaged over extended periods, in contrast to differentiated derivatives of many other EC lines. Further, both lines have receptors for and respond mitogenically to epidermal growth factor (EGF). Endogenous phosphorylation of several proteins, including the EGF receptor (150 kDa) and a 38-kDa protein, is induced by EGF in membranes isolated from these cells. Preincubation of membranes with EGF renders them able to catalyze phosphorylation of tyrosine residues in exogenously added peptide substrates. High voltage electrophoresis confirmed the tyrosine specificity of the phosphorylation on the 150- and 38-kDa bands. By contrast, similar experiments in undifferentiated cells showed that intact P19 EC neither bind nor respond to EGF mitogenically and EGF induces no changes in phosphorylation in isolated membranes.

Topics: Animals; Cell Differentiation; Cell Division; Clone Cells; Epidermal Growth Factor; ErbB Receptors; Mice; Phosphorylation; Protein Kinases; Teratoma

We investigated the ability of the teratocarcinoma-derived, epithelial-type cell line 1H5 to differentiate into either of the two pathways to primary endoderm, and tested the hypothesis that 1H5 represents a state similar to primitive endoderm in the late 4th-day blastocyst. Like other endodermal cell types, 1H5 cells mixed with embryonal-carcinoma cells sort out into "embryoid bodies" or structures that resemble 4th-day mouse embryos. The epithelial line conforms morphologically and biochemically to the few known characteristics typical of primitive endoderm. The present study demonstrates that the formation in vitro of overt visceral endoderm is readily achieved. The spontaneous arrangement of the cells into a cystic form is followed by the appearance of several markers of visceral endoderm, most notably alphafetoprotein, which is detected when 1H5 cells are cultured either in the presence of retinoic acid or when the cells interact with embryonal-carcinoma cells in a specific spatial arrangement after sorting out. However, some less specific properties of visceral endoderm are not expressed. Although 1H5 differentiates histologically into parietal-like endoderm in the tumor form, parietal cells cannot yet be identified with certainty in vitro because of the paucity of parietal-specific markers. The 1H5 cell line could provide a useful system for studying the characteristics and mechanisms underlying visceral-endoderm differentiation in vitro, since it has the distinct advantage that homogeneous cultures are produced, in contrast to other teratocarcinoma cell lines such as F9 which differentiate into a mixture of cell types.

Topics: Animals; Cell Aggregation; Cell Differentiation; Cell Line; Clone Cells; Culture Media; Endoderm; Epidermal Growth Factor; ErbB Receptors; Female; Mice; Ovarian Neoplasms; Plasminogen Activators; Receptors, Cell Surface; Teratoma

Substantial multiplication in vitro of cloned cells from a human embryonal carcinoma cell line, Tera 2, has been obtained in a basal medium (DMEM/Ham's F12,50:50, v/v) supplemented with 10 micrograms low density lipoprotein/ml, 100 micrograms high density lipoprotein/ml, 100 ng multiplication stimulating activity/ml, 100 ng insulin/ml and 1 microgram transferrin/ml. The growth rate appears to be similar to that obtained in 10% serum. Furthermore, studies on the expression of cell surface receptors revealed that cloned Tera 2 cells express high-affinity receptors for IGF-II but not for insulin. The cells also express receptors for Epidermal Growth Factor (EGF) even though the addition of EGF does not stimulate their proliferation in serum-free medium. These results suggest that the expression of specific growth factor receptors is not an absolute determinant of hormone responsiveness.

Topics: Cell Division; Cell Line; Clone Cells; Culture Media; Epidermal Growth Factor; Humans; Insulin; Peptides; Receptor, Insulin; Receptors, Cell Surface; Receptors, Somatomedin; Somatomedins; Teratoma

Retinoic acid (RA) has previously been shown to induce the differentiation of mouse embryonal carcinoma (EC) cells to endoderm-like cells that have a slower rate of proliferation and are nontumorigenic. These cells also acquire the ability to respond to a range of exogenous growth factors. We have analysed the change in growth phenotype for PC13 EC cells using video recordings and autoradiography. We have shown that the endoderm-like cells have a longer cell cycle time than their undifferentiated counterparts (five cell divisions after exposure to RA the differentiated cells had a median cell cycle time of 1800 min compared to 800 min for control cells). The endoderm-like cells also have a progressively decreasing probability of dividing again and this indicates that the differentiation process is accompanied by the acquisition of a limited life-span. The characteristics of mortal cells are well documented, and the endoderm-like cells demonstrate the properties of such cells. In addition, we have confirmed the observation that epidermal growth factor (EGF) can stimulate the proliferation of the endoderm-like cells and have shown, using autoradiography, that 92% of these cells express EGF receptors. Using video recordings, we have demonstrated that the effect of EGF is to shorten the cell cycle of the differentiating cells. We have also shown that EGF can enhance the survival of the endoderm-like cells and thereby prolong their life-span. It is known that EGF and other growth factors can prolong the life-span of mortal cells derived from normal tissues, but we have demonstrated that EGF can have this effect on the differentiated derivatives of a tumour cell.

Topics: Animals; Cell Cycle; Cell Division; Cell Survival; Cell Transformation, Neoplastic; Clone Cells; Culture Media; Epidermal Growth Factor; Mice; Neoplasms, Experimental; Teratoma; Tretinoin; Video Recording

Treatment of F9 teratocarcinoma cells with all trans retinoic acid (RA) causes them to differentiate into two or three morphologically distinct cell types. Whereas the majority of these retinoid-derived cells exhibit properties resembling parietal endoderm, a small percentage of this differentiated cell population manifests properties distinct from the parietal endoderm cell type. The isolation and partial characterization of such a non-parietal endoderm cell line (Dif 5) derived from F9 cells following prolonged (44 days) exposure to 1 microM retinoic acid are described. Unlike the retinoid-induced parietal endoderm-like cell population, which exhibits a dramatic, characteristic morphological change upon treatment with 8-bromo cAMP, Dif 5 cells do not show any morphological change with exposure to this cAMP analog. Dif 5 cells synthesize and deposit an extracellular matrix consisting of several components of Reichert's membrane (fibronectin, laminin, and type IV collagen). This new cell line does not synthesize alpha-fetoprotein but does secrete plasminogen activator. An interesting property of these cells is their ability to grow in the absence of serum or other hormonal supplements. Yet the Dif 5 cells do exhibit density-dependent inhibition of growth. Unlike the parent F9 cells or parietal yolk sac (PYS-2) cells, these cells do possess specific cell surface receptors for epidermal growth factor (EGF). The growth-arrested Dif 5 cells can be reinitiated to proliferate by the addition of fetal calf serum (FCS) or EGF. The properties of Dif 5 cells determined fail to fulfill all the characteristics described for either parietal or visceral endodermal cells. This raises the possibility that Dif 5 cells might represent an endodermal cell type which is intermediate in differentiation to either parietal or visceral endoderm but which lacks the biochemical signal to complete this stage of differentiation. This new Dif 5 cell line should be of considerable value in studying the modulation of growth requirements and extracellular matrix formation during early embryonic development.

Topics: alpha-Fetoproteins; Animals; Blood; Bucladesine; Cell Division; Cell Line; Cell Separation; Culture Media; Endoderm; Epidermal Growth Factor; Extracellular Matrix; Myristic Acids; Neoplasms, Experimental; Plasminogen Activators; Teratoma; Tretinoin

Embryonal carcinoma cell lines present strong developmental analogies with early embryonic cells. Previous studies have shown that treatment of F9 teratocarcinoma cells with retinoic acid induces the expression of the classical transplantation antigens which are indispensable for effective interactions between cells. In contrast to several genes that were analyzed, all of which were highly and heterogeneously methylated in F9 cells, the H-2K gene was poorly methylated if at all. Activation of the H-2K gene upon differentiation of F9 cells was accompanied by an increase in DNA methylation. While increased methylation of the H-2K gene in one of the two homologous chromosomes was correlated with a low level of expression, increased methylation in both chromosomes was associated with a high level of expression. Treatment of differentiated F9 cells with 5-azacytidine resulted in inhibition of DNA methylation and a concomitant repression of the H-2K gene expression. Thus, in contrast to the many examples of an inverse correlation between the level of gene methylation and its transcriptional activity, expression of the H-2K gene is directly correlated with the extent of methylation. This finding offers an explanation whereby the hypomethylation observed in tumor cells may be responsible for the establishment and maintenance of a malignant state of growth.

Topics: Animals; Azacitidine; Cell Line; DNA Restriction Enzymes; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Genes; H-2 Antigens; Major Histocompatibility Complex; Methylation; Mice; Nucleic Acid Hybridization; Poly A; Receptors, Cell Surface; RNA; RNA, Messenger; Teratoma

Topics: Animals; Caenorhabditis elegans Proteins; Carcinogens; Carrier Proteins; Cell Line; Epidermal Growth Factor; ErbB Receptors; Kinetics; Mice; Neoplasms, Experimental; Peptides; Phorbol 12,13-Dibutyrate; Phorbol Esters; Phorbols; Protein Kinase C; Receptors, Cell Surface; Receptors, Drug; Teratoma; Tetradecanoylphorbol Acetate

Embryonal carcinoma cells (EC cells) can form a wide variety of differentiated cell types and thus resemble the pluripotential stem cells of the normal embryo. Certain EC cell derivatives acquire the biochemical and morphological features of primitive endoderm and have been called 'END' or endodermlike cells. Although these have also been called 'giant' because of their large size, their nuclear DNA contents are not known. Since cell size often corresponds to DNA content and primitive endoderm becomes polyploid during the course of normal development, EC-derived endoderm has been studied cytophotometrically. Thus, EC- and embryo-derived endoderm were found to be similar in that both of these tissues undergo polyploidization. Moreover, the polyploid cells of either EC or embryonic origin do not appear to be terminal cell types, since they can occasionally enter renewed cell division in spite of their large size.

Topics: Animals; Cell Differentiation; Cell Line; Cells, Cultured; DNA; DNA, Neoplasm; Endoderm; Epidermal Growth Factor; Mice; Polyploidy; Teratoma

Topics: Animals; Blood; Cell Division; Cell Line; Culture Media; Epidermal Growth Factor; Growth Substances; Mice; Receptor, Insulin; Receptors, Drug; Teratoma; Transferrin

Mouse teratocarcinoma stem cells (embryonal carcinoma, or EC cells) bind very small amounts of mouse epidermal growth factor (EGF) and the latter hormone seems to have no stimulatory effect on the growth of two cloned lines of EC cells. However, when EC cells are induced to differentiate into large flat endodern-like cells (END cells), EGF receptors increase in number reaching a plateau in 6 to 8 days. At 8 to 10 days after induction, END cells multiply very slowly, but when EGF is added (3 x 10(-10) M) to the medium, cell division is stimulated and a further change in morphology occurs. This letter describes the binding characteristics and numbers of the EGF receptors on EC and END cells and shows that exogenous retinoic acid increases the numbers of EGF receptors on END cells. We were unable to find endogenous competing factors produced by EC cells. Such factors could account for the lack of detectable binding of EGF on these cells. As EC cells differentiate to END cells, so the ability of the cells to form tumours is reduced. Since this change is accompanied by an increase in the number of EGF receptors there may be a relationship between these two events.

Topics: Animals; Cell Differentiation; Cell Division; Cell Line; Epidermal Growth Factor; Mice; Neoplasms, Experimental; Peptides; Receptors, Cell Surface; Teratoma; Tretinoin