Aromatase mRNA Levels in Benign Prostatic Hyperplasia and Prostate Cancer

Background: Estrogens are suspected to play a role in the pathogenesis of benign prostatic hyperplasia (BPH) and prostate cancer. In this study, the expression of aromatase messenger ribonucleic acid (mRNA) was determined, and these levels were quantitated, in human prostatic tissues to evaluate the role of estrogens in the pathogenesis of BPH and prostate cancer. Methods: Prostatic tissues were obtained either by retropubic prostatectomy, radical prostatectomy, or radical cystectomy from patients with BPH, prostate cancer, and bladder cancer. The expression of aromatase mRNA in the prostatic tissues was studied by Southern blot analysis of the reverse transcription and polymerase chain reaction technique (RT-PCR) products. Aromatase mRNA levels were measured in human prostatic tissues by the RT-PCR using a fluorescent primer. Results: Aromatase mRNA was identified in all specimens by Southern blot analysis of the RT-PCR products. The concentrations of aromatase mRNA (mean ± SD) which were measured by fluorometric quantitation in 16 of 19 patients with BPH and in 3 of 4 patients with prostate cancer, were 1.81 ± 3.02, and 0.84 ± 0.27, ± 10--3 attomoles/μg of total RNA, respectively. Conclusions: These results demonstrate local formation of estrogen in the prostates of patients with BPH and prostate cancer. Controlled studies will be necessary to determine whether this may be a faclor in the development of BPH and prostate cancer.