title: The expression of prostate stem cell antigen in human clear cell renal cell carcinoma: a quantitative reverse transcriptase-polymerase chain reaction analysis.
abstract: OBJECTIVE
  To analyse the gene expression level of prostate stem cell antigen (PSCA) in human clear cell renal cell carcinoma (CC-RCC) and its relationship with conventional clinicopathological manifestations, to evaluate its prognostic value for patient outcome, and to determine the effect of PSCA on the progression of CC-RCC.
  
  
  METHODS
  We quantified PSCA mRNA level in human RCC cell lines (ACHN, A704, KPK-1, Caki-1, and Caki-2) and in 154 surgical tissue samples (81 from CC-RCC, 73 from normal kidney) using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The findings were analysed in relation to clinicopathological factors. Immunohistochemical expression was examined using confocal laser scanning light-microscopy.
  
  
  RESULTS
  PSCA was overexpressed in all RCC cell lines. PSCA mRNA levels were significantly higher in CC-RCC than in normal kidney tissue samples (P < 0.001), in G2-G3 than in G1 tumours (P = 0.028), and in advanced disease (T3-T4) than in organ-confined (T1-T2) tumours (P = 0.016). There was significantly higher PSCA mRNA expression in patients with M1 than in those with M0 disease (P = 0.029). Patients in whom the lesions had high PSCA expression levels had a significantly worse prognosis than those with low PSCA expression levels (P = 0.044). Using immunohistochemical analysis there was markedly greater PSCA expression in CC-RCC than in normal kidney, and in advanced-disease high-grade tumours than in organ-confined low-grade tumours.
  
  
  CONCLUSIONS
  A significant correlation was detected in the gene expression level of PSCA with histological grade, clinicopathological stage and prognosis in CC-RCC. Our data indicate that PSCA is associated with carcinogenesis and progression of CC-RCC.
authors.affiliation: Department of Urology and Department of Anatomy and Cell Biology, The University of Tokushima Graduate School Institute of Health Biosciences, Tokushima, Japan.
authors.forename: Essam M
authors.initials: EM
authors.lastname: Elsamman
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Fukumori
authors.forename: Shuji
authors.initials: S
authors.lastname: Tanimoto
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Nakanishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Toida
authors.forename: Hiro-Omi
authors.initials: HO
authors.lastname: Kanayama
mesh_terms: D000951:Antigens, Neoplasm; D002292:Carcinoma, Renal Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D058851:GPI-Linked Proteins; D015870:Gene Expression; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D000951:Antigens, Neoplasm; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C110843:PSCA protein, human