title: Type 1 vasoactive intestinal peptide receptor expression in PC3/AR cells is evidence of prostate epithelial differentiation.
abstract: BACKGROUND
  Type 1 vasoactive intestinal peptide receptor (VIP1R) is expressed in many secretory epithelial cells. We investigated VIP1R expression as a marker of prostate secretory epithelial differentiation in normal and malignant prostate tissues and in PC-3 human prostate cancer cells either lacking or expressing a functional androgen receptor.
  
  
  METHODS
  VIP1R mRNA in rat prostate was assessed by in situ hybridization. VIP1R mRNA in human prostate tissue was identified by Northern blot hybridization. VIP1R mRNA expression in human prostate cancer cell lines in the presence or absence of androgen was determined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Human prostate cell lines were treated with VIP, and changes in intracellular cAMP were measured by radioimmunoassay.
  
  
  RESULTS
  VIP1R mRNA was expressed only in epithelial cells in normal rat prostate. VIP1R mRNA was present in both normal and malignant human prostate. Well-differentiated LNCaP cells expressed functional VIP receptors, while poorly differentiated PC-3 cells did not. PC-3 cells stably expressing the androgen receptor (PC3/AR) did express functional VIP receptors, but VIP1R mRNA levels were not androgen-regulated.
  
  
  CONCLUSIONS
  VIP1R expression indicates epithelial differentiation in normal and malignant prostate. PC3/AR cells and LNCaP cells, both of which express VIP1R and prostate-specific antigen (PSA), are the only prostate cancer cell lines known to express these two markers of prostate epithelial differentiation.
authors.affiliation: Geriatric Research, Education, and Clinical Center and Research Service, Veterans Affairs Medical Center, Miami, Florida, USA. pgkonos@shadow.net
authors.forename: P J
authors.initials: PJ
authors.lastname: Gkonos
authors.forename: F
authors.initials: F
authors.lastname: Guo
authors.forename: K L
authors.initials: KL
authors.lastname: Burnstein
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis; D015152:Blotting, Northern; D002454:Cell Differentiation; D004847:Epithelial Cells / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D011467:Prostate / Q000166:cytology*; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D051381:Rats; D011944:Receptors, Androgen / Q000502:physiology*; D018005:Receptors, Vasoactive Intestinal Peptide / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D011944:Receptors, Androgen; D018005:Receptors, Vasoactive Intestinal Peptide; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I