In situ hybridization for gastrin‐releasing peptide receptor (GRP receptor) expression in prostatic carcinoma

• Published in: International journal of cancer Vol. 79; no. 1; pp. 82 - 90
• Main Authors: Bartholdi, Marty F., Wu, James M., Pu, Haifeng, Troncoso, Patricia, Eden, Peter A., Feldman, Richard I.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 20.02.1998; Wiley-Liss
• Subjects: Biological and medical sciences; Gastrin-Releasing Peptide - metabolism; Humans; In Situ Hybridization; Male; Medical sciences; Nephrology. Urinary tract diseases; Neurokinin B - analogs & derivatives; Neurokinin B - metabolism; Prostate - metabolism; Prostatic Hyperplasia - metabolism; Prostatic Neoplasms - genetics; Radioligand Assay; Receptors, Bombesin - genetics; RNA, Messenger - genetics; RNA, Neoplasm - genetics; Tumor Cells, Cultured; Tumors of the urinary system; Urinary tract. Prostate gland; Human; Urinary system disease; Bombesin; Prostate disease; Male; Case control study; Malignant tumor; Gene expression; Gastrin releasing peptide; Polymerase chain reaction; Male genital diseases; Prostate; Biological receptor
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/(SICI)1097-0215(19980220)79:1<82::AID-IJC16>3.0.CO;2-J

Bombesin‐like peptides (BLPs), which have been implicated in the regulation of growth of prostatic carcinoma cells, are a product of neuroendocrine cells frequently found in prostate tissue and are postulated to play a role in the initiation or progression of prostatic carcinoma. In this report, we examined the expression, in human prostate tissue, of mRNA encoding the 3 known receptors that respond to BLPs in humans, i.e., gastrin‐releasing peptide (GRP) receptor, neuromedin B (NMB) receptor and bombesin receptor subtype 3 (BRS‐3). Competitive rt‐PCR experiments demonstrated the widespread but variable expression of GRP receptor mRNA in fresh‐frozen specimens of prostatic carcinoma (12 cases) and benign prostatic hypertrophy (6 cases). NMB receptor mRNA expression was also widespread, but its level was less variable than GRP receptor message. In contrast, we could not detect BRS‐3 mRNA in most tissue samples by rt‐PCR. To address which cells in the prostate express the GRP receptor, we used in situ hybridization methods to stain selectively GRP receptor mRNA. GRP receptor mRNA was expressed predominantly in the luminal and basal epithelial cells in both histologically normal and cancerous glands within sections of normal (3 cases) and diseased (37 cases) tissue. GRP receptor mRNA staining in cancerous tissue ranged widely from very intense to not detectable (about 30% of the cases), while normal tissue consistently displayed a low level of message staining. Taken together, our results demonstrate expression of the GRP receptor in a high percentage of basal and/or luminal epithelial cells of normal and diseased prostate tissues. Int. J. Cancer (Pred. Oncol.) 79:82–90, 1998. © 1998 Wiley‐Liss, Inc.