title: Reduced expression of PSCA, a member of the LY-6 family of cell surface antigens, in bladder, esophagus, and stomach tumors.
abstract: Prostate stem cell antigen (PSCA) is a member of the LY-6 family of surface proteins that is overexpressed in prostate cancer. Using serial analysis of gene expression (SAGE), we identified PSCA as one of the most abundant transcripts in a differentiated urothelial tumor. As assessed by Northern blotting, PSCA is highly expressed in normal urothelium and noninvasive urothelial tumors. In contrast to the previously reported overexpression of PSCA in progressive and invasive forms of prostate cancer, we found a markedly reduced expression in undifferentiated bladder carcinoma. In addition, several aberrant splicing products derived from the PSCA gene were found in urothelial tumors. Furthermore, PSCA mRNA was highly abundant in normal esophagus and stomach, but was undetectable in esophageal or gastric tumors. The PSCA expression appeared to depend on cell contact, since mRNA levels were increased when RT112 bladder carcinoma cells were grown to confluence. Our data suggest that PSCA could serve as a potential marker for the early carcinogenesis in urothelial and gastric tissues and that its expression is specific for epithelial cells.
authors.affiliation: Institut für Pharmakologie und Toxikologie, RWTH Aachen, Aachen, D-52057, Germany. gregor.bahrenberg@post.rwth-aachen.de
authors.forename: G
authors.initials: G
authors.lastname: Bahrenberg
authors.forename: A
authors.initials: A
authors.lastname: Brauers
authors.forename: H G
authors.initials: HG
authors.lastname: Joost
authors.forename: G
authors.initials: G
authors.lastname: Jakse
mesh_terms: D017398:Alternative Splicing; D000950:Antigens, Ly / Q000235:genetics*; D000951:Antigens, Neoplasm / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D002452:Cell Count; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology; D004947:Esophagus / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D058851:GPI-Linked Proteins; D005753:Gastric Mucosa / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015603:Keratinocytes; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics*; D009928:Organ Specificity; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000166:cytology / Q000473:pathology; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology; D019459:Urothelium / Q000166:cytology / Q000378:metabolism / Q000473:pathology
chemical_list: D000950:Antigens, Ly; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C110843:PSCA protein, human; D012333:RNA, Messenger