Utilization of the Boyden chamber to further characterize in vitro migration and invasion of benign and malignant human prostatic epithelial cells

In the present study, we assessed various tissue culture conditions on the motility and invasiveness of benign and malignant prostatic epithelial cells using the Boyden chamber system. In DME and RPMI-1640 media, benign human prostatic epithelial cells were unable to penetrate through a basement-membrane-coated filter. However, the prostatic carcinoma cell lines, PC3 and DU145, showed a significant frequency of invasion under those conditions. When cultured in the low-calcium WAJC 404 medium, benign prostatic epithelial cells efficiently penetrated through the basement membrane-coated filter. PC3 and DU145 cells showed an attenuated capability to invade when cultured in WAJC 404 medium. The effect of extracellular calcium on the behavior of these cells in the Boyden chamber was further evaluated by gradual addition of calcium chloride in WAJC 404 medium. These studies showed that the number of benign prostatic epithelial cells penetrating through the filter decreased as the calcium ion concentration increased. Conversely, the number of PC3 cells invading through the filter increased as calcium ion concentration was increased to 0.4mM and decreased at higher calcium ion concentrations. These results suggest that the extracellular calcium concentration is one of the factors which may affect cell behavior in the Boyden chamber system.