Abstract
Prostate cancer (PCa) is the second most common type of male malignancy worldwide. The transcription factor zinc finger E‑box binding homeobox 1 (ZEB1) is associated with epithelial‑mesenchymal transition and is also involved in regulation of androgen receptor (AR) expression, the main ligands of which are testosterone and dihydrotestosterone (DHT). These androgens are synthesized through the steroidogenic pathway within the prostate, and their synthesis is altered in PCa. The present study aimed to determine the ZEB1‑induced alterations in androgen synthesis and AR expression in the DU145 PCa cell line. Reverse transcription‑quantitative polymerase chain reaction, western blotting and immunocytochemistry were used to determine the mRNA and protein expression levels, and cellular localization of steroidogenic pathway enzymes in the DU145 cell line in response to ZEB1 silencing. Furthermore, the concentrations of testosterone and DHT were detected in cell culture medium using ELISA. ZEB1‑silenced cells exhibited an increase in testosterone and DHT production, an increase in AR expression and an alteration in the steroidogenic pathway. In particular, steroidogenic acute regulatory protein and 5α‑reductase 2 expression levels were decreased, whereas cytochrome P450 family 17 subfamily A member 1, 5α‑reductase 1, aldo‑keto reductase family 1 member D1 and aldo‑keto reductase family 1 member C2 expression levels were increased. In conclusion, the present study provided novel information regarding the regulation of intratumoral androgen production in PCa, which is relevant for the progression of the disease to a castration‑resistant form.