ABSTRACT
In order to characterize the cell types grown in vitro, and to compare them to cell lineages in vivo, this chapter examines them for expression of potential markers of mammary epithelial cell maturation and differentiation. These include intermediate filaments, the large polymorphic epithelial mucins, extracellular matrix-associated proteins, and milk products. In order to examine factors which control normal HMEC proliferation, the chapter evaluates the effects of a variety of potential growth stimulators and growth inhibitors on the growth and differentiation of cells which display long-term growth in a serum-free medium. It aims to utilize chemical carcinogens and oncogenes to transform normal HMEC from reduction mammoplasty tissue to cell lines displaying indefinite lifespan, reduced growth factor requirements, and tumor formation in nude mice, in order to compare the properties of normal and transformed human mammary epithelial cells (HMEC). The chapter provides two main types of medium to support growth of the HMEC — a serum-containing medium, and a serum-free medium.
