title: C-type natriuretic peptide in prostate cancer.
abstract: C-type natriuretic peptide (CNP) is expressed in the male reproductive organs in pigs. To examine whether the human prostate also expresses the CNP gene, we measured CNP and N-terminal proCNP in prostate cancer tissue extracts and performed immunohistochemical biopsy staining. Additionally, proCNP-derived peptides were quantitated in plasma from patients with prostate cancer. Blood was collected from healthy controls and patients before surgery for localized prostate cancer. Tissue extracts were prepared from tissue biopsies obtained from radical prostatectomy surgery. N-terminal proCNP, proCNP (1-50) and CNP were measured in plasma and tissue extracts. Biopsies were stained for CNP-22 and N-terminal proCNP. Tissue extracts from human prostate cancer contained mostly N-terminal proCNP [median 5.3 pmol/g tissue (range 1.0-12.9)] and less CNP [0.14 pmol/g tissue (0.01-1.34)]. Immunohistochemistry demonstrated the presence of the peptides in prostatic epithelial cells. The N-terminal proCNP concentrations in plasma were marginally lower in patients with localized prostate cancer compared with control subjects [13.8 pmol/l (11.0-17.2) vs. 15.1 pmol/l (10.4-23.2), p=0.002] but not enough to justify the use of N-terminal proCNP as a cancer marker. Further research is needed to establish whether measurement of proCNP-derived peptides may offer clinical information.
authors.affiliation: Department of Clinical Biochemistry, Ringhospitalet, University of Copenhagen, Denmark.
authors.forename: Soeren Junge
authors.initials: SJ
authors.lastname: Nielsen
authors.forename: Peter
authors.initials: P
authors.lastname: Iversen
authors.forename: Jens F
authors.initials: JF
authors.lastname: Rehfeld
authors.forename: Helle Lone
authors.initials: HL
authors.lastname: Jensen
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Goetze
mesh_terms: D000368:Aged; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020098:Natriuretic Peptide, C-Type / Q000097:blood / Q000378:metabolism*; D011467:Prostate / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis / Q000378:metabolism*; D011498:Protein Precursors / Q000097:blood / Q000378:metabolism*; D011863:Radioimmunoassay
chemical_list: D011498:Protein Precursors; D020098:Natriuretic Peptide, C-Type