Regulation of prostatic stromal cell growth and function by transforming growth factor beta (TGFbeta)

The majority of the overgrowth in benign prostatic hyperplasia (BPH) specimens is comprised of connective tissue. Factors that control stromal growth in the prostate are poorly understood; however, members of the transforming growth factor beta (TGFbeta) family may be of particular importance in the etiology of BPH.

Thirty-two low-passage stromal cultures were generated from human prostatectomy specimens. Their stromal origin was confirmed and expression of TGFbetas analyzed by duplex reverse transcription-polymerase chain reaction (RT-PCR). Challenge experiments were designed to study the effects of exogenous TGFbeta1 on stromal cell growth and synthesis of extracellular matrix components.

The expression of TGFbetas 1, 2, and 3 was demonstrated in all 32 cell strains. The stromal origin of the cell lines was confirmed. Exogenous TGFbeta1 added to stromal cultures resulted in inhibition of cell growth and increased production of type I collagen.

The prostatic stromal cell strains we have developed are a reliable mod- el for investigating prostatic connective tissue biology. The challenge experiments with TGFbeta1 provide further evidence for the involvement of TGFbetas in prostatic enlargement, as modulators of the extracellular matrix in the absence of growth stimulation.