Induction of Hormone Receptors and Responsiveness during Cellular Differentiation

Abstract

The chapter focuses primarily on the hormone-sensitive adenylate cyclase system as one indication of the state of cellular differentiation. During the process of differentiation, cells acquire various specialized functions, and the responsiveness of cells to hormones is often associated with a more differentiated state. Differentiation is a complex process. Even when studying a single function, such as hormone sensitivity, numerous other factors must be considered. Therefore, by using cultured cells, the cellular environment can be brought under better control, thus reducing the number of variables within the experimentation. Due to adaptation to artificial growth conditions, established cell cultures often become partially dedifferentiated and, in many cases, no longer retain the initial cellular characteristics. Certain chemical compounds induce differentiated functions in several established cell lines. Friend erythroleukemic cells (a line of erythroblasts transformed with Friend leukemia virus) and HeLa cells derived from a human cervical carcinoma, are well characterized in this regard. Various model systems such as 3T3-LI adipocyte, liver cells, granulosa cells, and Madin-Darby Canine kidney (MDCK) cells are discussed.