Retinoic acid induces embryonal carcinoma cells to differentiate into neurons and glial cells.

Abstract

Murine embryonal carcinoma cells can differentiate into a varied spectrum of cell types. We observed the abundant and precocious development of neuronlike cells when embryonal carcinoma cells of various pluripotent lines were aggregated and cultured in the presence of nontoxic concentrations of retinoic acid. Neuronlike cells were also formed in retinoic acid-treated cultures of the embryonal carcinoma line, P19, which does not differentiate into neurons in the absence of the drug. The neuronal nature of these cells was confirmed by their staining with antiserum directed against neurofilament protein in indirect immunofluorescence experiments. Retinoic acid-treated cultures also contained elevated acetylcholinesterase activity. Glial cells, identified by immunofluorescence analysis of their intermediate filaments, and a population of fibroblastlike cells were also present in retinoic acid-treated cultures of P19 cells. We did not observe embryonal carcinoma, muscle, or epithelial cells in these cultures.Neurons and glial cells appeared in cultures exposed to retinoic acid for as little as 48 h. We found no evidence for retinoic acid toxicity, suggesting that the effect of the drug was to induce the development of neurons and glia rather than to select against cells differentiating along other developmental pathways.Very little is known about the determination events that commit unspecialized cells to differentiate into the more specialized cell types that appear later during embryonic development. Murine embryonal carcinoma cells, the pluripotent stem cells of malignant teratocarcinomas, may provide a culture system with which to study these events (16). Lines of embryonal carcinoma cells can be isolated from teratocarcinomas and maintained in an undifferentiated state when kept in exponential growth phase in tissue culture (1 l, 23, 41). If left undisturbed at high density, they differentiate in vitro into a variety of cell types including epithelium, neurons, muscle, and cartilage (29,30,36).The value of the embryonal carcinoma cells in studying determination has been limited by the complexity of their differentiation patterns; any one determination event is obscured from study by others that occur simultaneously. We attempted to limit the spectrum of cell types arising during embryonal carcinoma differentiation by identifying drugs that either blocked certain avenues of differentiation or induced embryonal carcinoma cells to differentiate into specific cell types. This paper describes the effects of retinoic acid. This THE JOURNAl. Ol ~ CrtL 8tOLOGV -VOLUME 94 AUGUS] 1982 253-262

Absence of p53-dependent cell cycle regulation in pluripotent mouse cell lines

“…P19 cells respond to retinoic acid by di erentiating into neurons, astrocytes and oligodendrocytes (Staines et al, 1996;Jones-Villeneuve et al, 1982). There is a suggestion from p53 de®cient mice that precocious neurogenesis may result from the absence of p53 (Hall and Lane, 1997), a result consistent with the abundant development of neurons from P19 cells.…”

RAR-mediated epigenetic control of the cytochrome P450 Cyp26a1 in embryocarcinoma cells

“…P19, which carries a normal RARa, is growth-inhibited and can differentiate into neurons in response to RA (Jones-Villeneuve et al, 1982;Edwards and McBurney, 1983). In contrast, its mutant counterpart, the RAC65 cell line, is RA-resistant and cannot differentiate when grown as aggregates (Jones-Villeneuve et al, 1983).…”

Retinoic acid induces secretion of transforming growth factors by PC12 pheochromocytoma cells

“…The actions of RA are mediated by nuclear receptors (RARs and RXRs) which belong to the steroid/thyroid hormone receptor superfamily and act as ligand-inducible transcription factors (for a recent review see Guiguere, 1994). RA is known to inhibit proliferation and to stimulate morphological di erentiation in neuroblastoma cells Sidell et al, 1983;Kaplan et al, 1993) and to induce neuronal di erentiation of teratocarcinoma cells (Jones-Villeneuve et al, 1982). We have recently shown that RA also profoundly a ects growth, di erentiation and gene expression on PC12 cells .…”