Embryonal carcinoma cell line

Embryonal carcinoma cell lines have also been established in culture from transplantable teratocarcinomas. The embryonal carcinoma (EC) stem cells present in the tumors actually differentiated, and give rise to a variety of different types of embiyonic and adult cells. When these EC cells are cultured, they still possess the... 

The implementation of animal test protocols in the 1980s has been accompanied by the development of a host of alternative methods to study adverse effects of chemicals on reproductive and developmental parameters. For example, rat whole embryo culture stems from the seventies (16), as does the rat limb bud organ culture (17) and rat limb bud and brain micromass was developed in the eighties (18). An elegant nonvertebrate alternative model used regeneration of polyps of Hydra atUnuata from dissociated cells (19). Animal-free in vitro alternatives include those employing the proliferation of a human embryonic palatal mesenchymal cell line (20), the attachment of a mouse ovarian tumor cell line (21), and the differentiation of a neuroblastoma cell line (22) and a embryonal carcinoma cell line (23). Various overviews of methods have been published over the years (24). The predictability of... 

Jetten, A.M., Jetten, M.E.R. Sherman, M.I. (1979b) Stimulation of Differentiation of Several Murine Embryonal Carcinoma Cell Lines by Retinoic Acid , Experimental Cell Research, 124, 381-91... 

It is of interest that retinoic acid bound to CRABP can apparently be extracted from the nuclei of an embryonal carcinoma cell line (Jetten and Jetten, 1979), retinoblastoma cell line (Wiggert et al., 1977b), and rat mammary carcinomas (Moon and Mehta, 1981). CRABP was also reported in the nuclei of embiyonic chick skin (Sani and Donovan, 1979). This suggests there may be fundamental differences in the way that CRABP and retinoic acid interact with the nucleus compared with CRBP and retinol. 

Mutants of the wild type S91-C2 melanoma cells have been isolated that are resistant to the antiproliferative action of retinoic acid (Lotan et al., 1983b). The mutant cells were also resistant to growth inhibition by retinol and a retinoidal benzoic acid derivative, suggesting a single growth-inhibitory mechanism common to all of these retinoids. Uptake of the retinoids was unimpaired in the mutant cells, and the cells had normal levels of CRABP. These results contrast with those of the retinoid-resistant embryonal carcinoma cell line mutants that were deficient in CRABP (Schindler et al., 1981). Eventually a mechanism of action of the retinoids will have to be described that can explain these diverse results, and mutants such as these should prove invaluable to such studies. 

That enhancer regions may be more or less effective in different cell types was originally suggested by studies on polyoma virus. Wild-type virus normally multiplies well in mouse cells of many types but will not propagate in undifferentiated embryonal carcinoma cell lines due to a block in the initiation of viral transcription (Dandolo et al.,... 

Blank RS, Swartz EA, Thompson MM. Olson EN, Owens GK (1995) A retinoic acid-induced clonal cell line derived from multipotential P19 embryonal carcinoma cells expresses smoothjnuscle characteristics. Circ Res 76 742-749... 

A variety of cell lines, including murine-F9 embryonal-carcinoma cells, murine-melanoma cells (B16 and S9), HeLa cells and HL-60 promyelocytic leukemia cells, have been successfully used for the extraction of RARs from nuclei (1,9). For cell lines growing as monolayers, we have used three 75-cm flasks at cell densities of 5 x 10 to 10 cells per flask for a typical experiment. In the case of HL-60 cells, which grow only in suspension culture, the cells are normally maintained at densities of 0.3 x 10 to 0.9 x 10 cells/mL but may be... 

Fig. 5. Comparison of Northern blot (lanes 1-4) and semiquantitative RT/PCR (lanes 5-8) results. Both methods were used to analyze expression of RARal and RARa2 isoforms in different human cell lines. Note that as expected the expression of RARa2 is induced with RA in T Clu embryonal-carcinoma cells. In this experiment, 30 cycles of PCR have been carried out. Note that RT/PCR is considerably more sensitive (compare lines 1 to 5-8) and generates results which are in agreement with the Northern blot.

In contrast to the murine embryonal carcinoma cells, several human teratocar-cinoma-derived cell lines fail to differentiate when treated with retinoic acid (Matthaei et al., 1983). Yet unlike the mutant murine cells that are refractory to retinoic acid, it has been shown that the human cell lines contain high levels of CRABP. These results and other data presented in the ensuing portions of this chapter make it unclear whether the retinoic acid-CRABP complex plays an obligatory role in the mechanism of promotion of differentiation. 

Advances in cell culture techniques have allowed the use of trophoblast cell cultures to evaluate the various transporter and metabolic systems of the placenta. Many studies have used primary cultures of undifferentiated cytotro-phoblasts isolated from placentas, whereas others have used trophoblast cell lines as a model. Trophoblast cell lines can be generated from normal tissues or malignant tissues and also from embryonal carcinomas exhibiting trophoblast differentiation [48],... 

Cotte, C., Raghavan, D., McDhinney, R. A. and Monaghan, R (1982). Characterization of a new human cell line derived from a xenografted embryonal carcinoma, fri Vitro 18,139-149. 

The human cell lines HeLa and KB produce ferritins that are electro-phoretically distinct from normal human ferritins (18, 142), although they have close similarities to human ferritins in their immunological properties (18). Similar observations have been made with two strains of embryonic human skin cells and with HEP-2 carcinoma cells (17). Since these early reports the presence of new molecular forms of ferritin in neoplastic cells has been widely observed (143, 144). 

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