EPIDERMAL GROWTH-FACTOR, EPIDERMAL GROWTH-FACTOR RECEPTOR, AND TRANSFORMING GROWTH FACTOR-A IN HUMAN HYPERPLASTIC PROSTATE TISSUE - EXPRESSION AND CELLULAR-LOCALIZATION

It is widely accepted that polypeptide growth factors are involved in the growth and development of normal and neoplastic human prostate. It has been previously reported that epidermal growth factor (EGF) and i nsulin-like growth factor I (IGF-I) receptors are present in the human hyperplastic prostate tissue (BPH). To add information on the mechani sm of action of EGF and transforming growth factor-alpha (TGF alpha), a peptide correlated to EGF, and the EGF receptor (EGF-R) in the human prostate, we studied the expression and cellular localization of mess enger ribonucleic acid (RNA) encoding EGF, EGF-R, and TGF alpha in BPH tissue. Reverse transcriptase-PCR of total RNA extracted from BPH tis sues documented the presence of specific transcripts for EGF, EGF-R, a nd TGF alpha. In situ hybridization with specific RNA probes synthesiz ed from the respective complementary DNA demonstrated that EGF, EGF-R, and TGF alpha messenger RNAs were mainly localized in the epithelial cells. Immunprecipitation and Western blot analysis showed that BPH ti ssue contained the corresponding proteins, EGF and TGF alpha. Our find ings provide additional support for the idea that EGF and TGF alpha ma y be considered specialized symbols in the language of cell-cell inter actions and for the hypothesis that in the human prostate they seem to act in an autocrine fashion.