title: Analysis of expression of chorionic gonadotrophin transcripts in prostate cancer by quantitative Taqman and a modified molecular beacon RT-PCR.
abstract: Expression of human chorionic gonadotrophin (hCG) is associated with trophoblastic, testicular and other malignancies such as bladder, pancreatic, cervical, breast and prostate cancer. In the prostate, however, hCG expression, associated with neuroendocrine cells, is also found in normal tissue. Of the six highly homologous genes that all encode the beta-subunit of hCG, the beta 7 gene is reportedly the only gene expressed in several non-transformed tissues. The beta 3, 5 and 8 genes would be variably expressed in malignant tissue and placenta, but not in normal tissue. To assess to what extent this expression difference can also be found in the prostate, we compared the levels of the different hCG beta transcripts in concurrent normal and cancerous prostate tissues obtained from 17 patients. To this end, we developed a Taqman real-time fluorescent RT-PCR assay for hCG beta, and a quantitative assay specific for the beta 3, 5 and 8 genes, modified from the molecular beacon principle. This latter assay proved highly specific and capable of reliably distinguishing between these hCG beta transcripts that differ in only one nucleotide. Surprisingly, median expression levels of hCG beta were lower in prostate cancer when compared with normal tissue from the same patient. In contrast, hCG beta 3, 5 and 8 transcripts were found in normal tissue and did not differ in prostate cancer, arguing against a specific role of these transcripts in the development of prostate cancer.
authors.affiliation: Department of Chemical Endocrinology, University Medical Centre Nijmegen, Nijmegen, The Netherlands. p.span@ace.azn.nl
authors.forename: P N
authors.initials: PN
authors.lastname: Span
authors.forename: C M G
authors.initials: CM
authors.lastname: Thomas
authors.forename: J J
authors.initials: JJ
authors.lastname: Heuvel
authors.forename: R R
authors.initials: RR
authors.lastname: Bosch
authors.forename: J A
authors.initials: JA
authors.lastname: Schalken
authors.forename: L
authors.initials: L
authors.lastname: vd Locht
authors.forename: E J B M
authors.initials: EJ
authors.lastname: Mensink
authors.forename: C G J
authors.initials: CG
authors.lastname: Sweep
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D016022:Case-Control Studies; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000032:analysis*; D006801:Humans; D008297:Male; D011467:Prostate / Q000737:chemistry*; D011471:Prostatic Neoplasms / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric
chemical_list: D014408:Biomarkers, Tumor; D018997:Chorionic Gonadotropin, beta Subunit, Human