Spontaneous differentiation of murine teratocarcinoma stem cells at low temperature.

Embryonal carcinoma cells differentiate in vitro after treatment with different drugs or under certain culture conditions. We show here that at 31 degrees C PCC-aza-1 cells differentiated spontaneously into cells with characteristics resembling those of epithelial cells. With this temperature, we observed morphological changes; reorganization of the cytoskeleton with polymerization of actin cables, tight junctions, and cytokeratin endo A messenger RNA and protein expression. The cells also became totally permissive to Py virus but remained resistant to SV40 infection. This new pathway of differentiation has the advantage of being reversible at 37 degrees C.