Requirements for attachment and subsequent growth of canine prostatic epithelial cells in culture

The attachment and spreading of canine prostatic epithelial cells in primary monolayers and their subsequent proliferation were studied in Primaria and in polystyrene dishes either uncoated or coated with collagen type I, fibronectin, laminin, poly-D-lysine, or natural extracellular matrices (nECM) produced by canine prostatic epithelial or fibroblastic cells. Cells were inoculated in serum-free medium or in medium supplemented with either dialyzed fetal bovine serum (dFBS) or charcoal-treated dog serum at 10%. Dihydrotestosterone (DHT) and 5 alpha-androstane 3 alpha, 17 beta-diol (3 alpha, 17 beta-diol) at 10(-6) M or a mixture of steroids (androstenedione, testosterone, DHT, 3 alpha, 17 beta-diol, 5 alpha-androstane 3 beta, 17 beta-diol, estrone, and estradiol) were also added. Of all components and dishes tested, only dFBS and the nECM produced by prostatic epithelial cells increased cell attachment (850% and 450%, respectively). When the latter preparations were used in combination, an additive effect (1,500%) was observed, and the subsequent addition of dog serum after the attachment period yielded the highest number of growing prostatic epithelial cells. When prostatic epithelial cells were inoculated either in dishes coated with a nECM derived from prostatic fibroblasts or in presence of dog serum, a 50% inhibition in their plating efficiency was observed. The presence of collagen type I, fibronectin, laminin, or an nECM in the cultures, together with various steroids, had no effect on the cell unresponsiveness to steroids nor did it alter the mitogenic effect of dog serum. Thus, the attachment and spreading of canine prostatic epithelial cells in monolayers are mediated by nonsteroidal factors present in dFBS and in their nECM. Their presence, together with steroids, does not elicit a proliferative response to steroids nor did it increase the effect of growth-promoting factors in dog serum.