Apoptosis during retinoic acid-induced differentiation of F9 embryonal carcinoma cells.

In this work we have characterized a process of cell death by apoptosis occurring in retinoic acid-induced differentiation of F9 embryonal carcinoma cells. Morphological changes corresponding to apoptosis were observed concomitantly with those of differentiated phenotype, in cell cultures treated for 48 h with physiological concentrations of all-trans-retinoic acid. Internucleosomal DNA fragmentation was also detected using agarose gels. These observations show that retinoic acid can induce both differentiation and apoptosis in an experimental system--the teratocarcinoma stem cell lines--widely used so far in the study of differentiation. We present this system as a tool for a better understanding of the role of retinoic acid in the regulation of cell differentiation and programmed cell death.