Profiling the Teratoma as a Model of in vivo Differentiation
Stem cells have the ability of unlimited self-renewal and can differentiate into specific cell types. These characteristics have made stem cells an important topic in the field of regenerative medicine and developmental cell biology. They can be used to model differentiation and develop therapeutic cell types. Stem cells can differentiate into the specific cell lineage spontaneously in vitro within embryoid bodies and in vivo within teratomas. Teratomas derived from implantation of pluripotent stem cells into live hosts can develop complex, mature tissues from all three developmental germ layers just four weeks post- implantation and are used to assess the pluripotency of a cell line. However, the spontaneous differentiation that occurs in teratoma development has not been widely studied and profiled. We discovered a cardiomyocyte population within teratomas generated from mouse embryonic stem cells verified through the expression of mature markers (Tnnt2 and Myl2) and positive staining regions for Tnnt2 and TropI. Additionally, we were able to investigate the early expression profiles of teratomas. Our results demonstrate that the teratoma can be further manipulated to study and enrich the differentiation of specific cell types. Currently, in vitro differentiation can take months to complete and is not very cost effective. Therefore, the teratoma can offer a cheaper and easier alternative to the generation of cell populations and the study of they may spontaneously arise.