Identification of genes associated with stromal hyperplasia and glandular atrophy of the prostate by mRNA differential display.

Despite the well-characterized histology associated with benign prostatic hyperplasia, very little is known about the underlying etiology of the disease on a molecular basis. The objective of this study was to use the technique of mRNA differential display in order to identify genes differentially expressed in human transition zone prostate tissue with high stromal density, with high epithelial density, and with nonhyperplastic histology. The extracellular matrix chondroitin/dermatan sulfate proteoglycan (CDSP) mRNA was more abundantly expressed in tissue with high stromal density, consistent with earlier findings that dermatan and chondroitin 6-sulfate glycosaminoglycans are increased in hyperplastic prostates. Messenger RNA encoding the negative regulator of cell cycle progression, BTG2, was more abundantly expressed in tissue with high epithelial densities. CDSP mRNA was abundantly expressed in primary cultures of stromal cells but was undetectable in epithelial cells. BTG2 mRNA was expressed in primary cultures of both cell types, but more abundantly in epithelial cells. BTG2 mRNA, but not CDSP mRNA, was subject to significant growth cycle regulation in cultured stromal and epithelial cells, with maximum expression occurring in quiescent cells. Generation of specific antibodies to BTG2 revealed that this protein was expressed at low levels in stroma, nonhyperplastic glands, and in hyperplastic glands. Consistent with a role in cell-cycle regulation, BTG2 protein was abundantly expressed in atrophic glands and preatrophic glands.