5 alpha-reductase in intact DU145 cells: evidence for isozyme I and evaluation of novel inhibitors.

The epithelial-like human prostatic carcinoma cell line DU145, which expresses 5 alpha-reductase type I isozyme, was used to test a series of potential 5 alpha-reductase inhibitors. The exclusive expression of the type I isozyme was confirmed by PCR and subsequent DNA sequence analysis. Culture conditions were optimized for high conversion rates. Using this whole cell assay finasteride, 4MA, and 65 steroidal and non-steroidal compounds synthesized in our group were tested for their inhibitory activity. Inhibitors with IC50 values in the nanomolar range could be identified.