Terminally differentiating epithelial tissues in primary explant culture: a model of growth and development

Many epithelial tissues are characterized by the presence of basal cells which serve the dual roles of self-renewal and of progression through terminal differentiation, to a functional state. Such tissues, when grown in vitro as primary explants, exhibit a characteristic pattern of outgrowth and development which includes both renewal and efforts toward normal differentiation. The degree of differentiation achieved depends upon conditions of culture and may be modulated in a variety of ways. The human prostate constitutes such a system and offers numerous possibilities for investigating basic control mechanisms in growth and development. Information on a variety of epithelial tissues is reviewed and experimental results using human prostate tissue are presented.