Expression and action of the growth hormone releasing peptide ghrelin and its receptor in prostate cancer cell lines

• Published in: Journal of endocrinology Vol. 172; no. 3; pp. R7 - 11
• Main Authors: Jeffery, PL, Herington, AC, Chopin, LK
• Format: Journal Article
• Language: English
• Published: Colchester BioScientifica 01-03-2002; Portland Press
• Subjects: Biological and medical sciences; Ghrelin; Humans; Male; Peptide Hormones; Peptides - genetics; Peptides - metabolism; Prostatic Neoplasms - metabolism; Protein Isoforms - metabolism; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Receptors, G-Protein-Coupled; Receptors, Ghrelin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Tumor Cells, Cultured
• ISSN: 0022-0795; 1479-6805
• DOI: 10.1677/joe.0.172r007

This study has examined the expression of two new facets of the growth hormone axis, the growth hormone secretagogue receptor (GHS-R) and its recently identified putative natural ligand ghrelin, in prostate cancer cells. GHS-R 1a and 1b isoforms and ghrelin mRNA expression were detected by RT-PCR in the ALVA-41, LNCaP, DU145 and PC3 prostate cancer cell lines. A normal prostate cDNA library expressed GHS-R1a, but not the 1b isoform or ghrelin. Immunohistochemical staining for the GHS-R 1a isoform and ghrelin was positive in the four cell lines studied. PC3 cells showed increased cell proliferation in vitro in response to ghrelin to levels 33% above untreated controls, implying a potential tumour-promoting role for ghrelin in this tissue. This study is the first to demonstrate the co-expression of the GHS-R and ghrelin in prostate cancer cells. It is also the first study to provide evidence that a previously unrecognised autocrine/paracrine pathway involving ghrelin, that is capable of stimulating growth, exists in prostate cancer.