Expression of growth hormone receptor in human prostatic carcinoma and hyperplasia

By reverse transcription-polymerase chain reaction the transcript of the growth hormone receptor (GHR) was proved in 21 human prostatic carcinomas and 19 benign prostatic hyperplasias. A new method for extracting RNA from paraffin-embedded tissue was established. Western immunoblotting using the monoclonal antibody mAb 263 revealed that the growth hormone receptor protein is equally expressed in prostatic carcinoma and hyperplasia. As shown by immunohistochemistry, the GHR protein is synthesized in the epithelial cells of the tumor acini. On the contrary, GHR was not found in normal prostatic epithelium. Our results imply that the growth hormone receptor may facilitate prostatic tumor cell growth.