Proliferation and differentiation of canine prostatic epithelial cells in culture

When cultured in monolayers, non-secretory epithelial cells from canine prostates actively synthesize DNA, RNA and proteins; subsequently, mitotic figures and an increase in cell number are observed. During this culture period, cell size and acid phosphatase activity remain constant. As the culture proceeds, these cells mature into secretory cells as evidenced by a gradual shift in their density in Percoll gradients to the density of secretory cells and by an increase in the cellular content of acid phosphatase. During maturation, the size of the non-secretory cells increases and their morphology changes and becomes similar to that of the secretory cells. When a homogeneous population of secretory cells is cultured, DNA synthesis is minimal and few mitotic figures may be observed while cell number and cell density remain constant. Early in the culture period, their size increases and by 2 weeks their acid phosphatase activity is 2--3-fold higher than that of the non-secretory cells. Thus, upon culture, the non-secretory epithelial cells enter and proceed through the cell cycle with evidence of DNA synthesis and mitosis. Those cells leaving the cycle undergo maturation into secretory cells which further differentiate with the concomitant appearance of acid phosphatase activity. This model will be useful to study prostatic hyperplasia and hypertrophy and the control mechanisms involved in these phenomena.