Estrogen formation in human prostatic tissue from patients with and without benign prostatic hyperplasia

Area of Science:

• Endocrinology
• Urology
• Biochemistry

Background:

• Benign prostatic hyperplasia (BPH) and prostate cancer are common conditions.
• The role of local estrogen formation in prostate disease is not fully understood.

Purpose of the Study:

• To investigate estrogen formation in human prostatic tissue.
• To determine the role of aromatase and 5 alpha-reductase in this process.
• To explore the potential link between local estrogen production and BPH.

Main Methods:

• Prostatic tissue from cystoprostatectomy was divided into periurethral and peripheral zones.
• Tissue homogenates were incubated with radiolabeled androstenedione in the presence of aromatase (4-hydroxyandrostenedione) and 5 alpha-reductase (4-MA) inhibitors.
• Estrogen formation was quantified using reverse isotope dilution and crystallization.

Main Results:

• Estrogen production was higher in the periurethral zone of patients with BPH compared to those without.
• Estrogen formation was also elevated in the peripheral zone of patients with BPH.
• Aromatase inhibition significantly reduced estrogen formation, with 4-MA showing potent inhibition.
• Prostatic aromatase followed Michaelis-Menton kinetics with an apparent Km of 90 nM.

Conclusions:

• The human prostate actively converts androgens to estrogens.
• Local estrogen synthesis is substantial and potentially higher in BPH.
• These findings suggest that local estrogen formation may play a role in the etiology of BPH and prostate cancer.