title: Differential expression and clinical relevance of MUC1 in renal cell carcinoma metastasis.
abstract: OBJECTIVE
  To determine the differential expression patterns and prognostic relevance of Mucin-1 (MUC1) expression in clear cell renal cell carcinoma (RCC) metastasis.
  
  
  METHODS
  Tissue microarrays (TMA) from samples of 151 RCC metastases, 61 primary RCCs and corresponding benign renal tissues were immunohistochemically stained for MUC1 and semi-quantitatively evaluated by immunoreactivity scores (IRS). MUC1 differential expression in metastasis, primary RCC and normal tissue were comparatively analyzed. Patient characteristics and clinical follow-up for patients with metastatic RCC (mRCC) were recorded. Correlations of MUC1 expression with mRCC survival were determined.
  
  
  RESULTS
  Median cytoplasmic expression was highest in benign tissue (IRS = 1.04). Primary RCC (0.50) and metastasis (0.12) showed significantly lower cytoplasmic staining intensity. Membranous expression in benign tissue was, however, significantly lower (0.21) compared with primary RCC (0.59) and metastasis (0.57). Notable differences of MUC1 cytoplasmic and membranous expression were observed between different metastasis sites. Significantly higher (P = 0.014) membranous expression was observed in pulmonary versus non-pulmonary lesions, while no significant differences of cytoplasmic MUC1 expression were observed. The prognostic relevance of MUC1 expression in metastatic RCC was limited.
  
  
  CONCLUSIONS
  MUC1 is differentially expressed in benign renal tissue, primary RCC and RCC metastasis. Membranous MUC1 expression was significantly elevated in pulmonary metastases compared to non-pulmonary lesions, which may reflect individual biology and putative response to MUC1-based anti-cancer therapy.
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Rausch
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Beermann
authors.affiliation: Department of Pathology, Eberhard-Karls-University Tübingen, Liebermeisterstraße 8, 72076, Tübingen, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Scharpf
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Hennenlotter
authors.affiliation: Department of Pathology, Eberhard-Karls-University Tübingen, Liebermeisterstraße 8, 72076, Tübingen, Germany.
authors.forename: Falko
authors.initials: F
authors.lastname: Fend
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Arnulf
authors.initials: A
authors.lastname: Stenzl
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schollenberger
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany. bedke@live.com.
authors.forename: Jens
authors.initials: J
authors.lastname: Bedke
authors.affiliation: Department of Urology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kruck
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000378:metabolism* / Q000556:secondary; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D018396:Mucin-1 / Q000096:biosynthesis*; D009362:Neoplasm Metastasis; D011379:Prognosis; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1
keywords: Clear cell; Metastasis; Mucin; Prognosis; Renal cell cancer