title: Expression and action of the growth hormone releasing peptide ghrelin and its receptor in prostate cancer cell lines.
abstract: 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.
authors.affiliation: Centre for Molecular Biotechnology, Queensland University of Technology, Brisbane, Queensland, Australia. p.jeffrey@qut.edu.au
authors.forename: P L
authors.initials: PL
authors.lastname: Jeffery
authors.forename: A C
authors.initials: AC
authors.lastname: Herington
authors.forename: L K
authors.initials: LK
authors.lastname: Chopin
mesh_terms: D054439:Ghrelin; D006801:Humans; D008297:Male; D036361:Peptide Hormones; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D054439:Ghrelin; D036361:Peptide Hormones; D010455:Peptides; D020033:Protein Isoforms; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin