Twenty one years of P19 cells: what an embryonal carcinoma cell line taught us about cardiomyocyte differentiation.

Many different stem cell types have been shown to differentiate into cardiac muscle cells in vitro but P19 embryonal carcinoma (EC) cells were one of the first examples described and have been the most extensively characterized. P19 EC cells, isolated from an experimental embryo-derived teratocarcinoma in mice, are multipotent and can differentiate into cell types of all three germ layers. Because of their capacity to form cardiomyocytes however, they have been used to dissect the role of cardiac-specific transcription factors and upstream signalling pathways in cardiac cell differentiation. Furthermore, they have shed light on unique aspects of cardiac cell physiology during heart cell differentiation, including regulation of the proteins underlying the electrical and contractile systems. Here, we review studies on different subclones of P19 cells, and what they have taught us about cardiac differentiation and physiology.