ABSTRACT
The 3D in vitro models are highly varied and can be composed of many different matrices and cell types. A study of human breast epithelium demonstrated the presence of mammary epithelial cells possessing the ability to regenerate elaborate branching structures resembling TDLUs both by morphology and marker expression, in vivo using xenotransplantation models and in vitro. The growth and study of mammary and breast stem cells in vitro has been limited prior to the introduction of 3D models. The introduction and refinement of the 3D in vitro systems have allowed for increased cellular manipulations to occur, thus, generating an expanded knowledge base. This chapter highlights advancements in the field of normal and cancer breast/mammary stem cells that have been made using the 3D in vitro systems. It focuses on gel-based solid culture systems and the free-floating mammosphere culture system as well as heterotypic 3D systems.
