Background: Expression of transforming growth factor-beta (TGF-beta) in the prostate has been reported. The purpose of this study was to evaluate the effect of TGF-beta on collagen synthesis by stromal cells isolated from a patient with benign prostatic hyperplasia (BPH).
Methods: Human prostatic stromal cells (HPSC) derived from BPH tissue were cultured in serum-free medium. After incubation with TGF-beta1, the concentration of procollagen type I C-peptide (PIP) in the HPSC-conditioned medium was measured by enzyme immunoassay while the concentration of procollagen type III N-peptide (PIIIP) was measured by radioimmunoassay. Per-cell production of each type of collagen was calculated by multiplying the measured concentration by the volume of medium and dividing by the number of harvested cells.
Results: One ng/mL of TGF-beta1 significantly (P < 0.05) increased collagen production by HPSC, to 220% and 120% of control for types I and III, respectively. Increasing the amount of TGF-beta1 to 10 ng/mL had no further effect. TGF-beta1 did not significantly affect HPSC number at concentrations of either 1 or 10 ng/mL. There was a strong correlation between PIP and PIIIP production (r = 0.929, P < 0.001).
Conclusion: These findings suggest that TGF-beta1 stimulates accumulation of extracellular matrix in stromal BPH tissue without affecting proliferation of stromal cells.