title: Caveolin 1 mRNA is overexpressed in malignant renal tissue and might serve as a novel diagnostic marker for renal cancer.
abstract: OBJECTIVE
  Caveolae play a significant role in disease phenotypes, such as cancer, diabetes, bladder dysfunction and muscular dystrophy. The aim of this study was to elucidate the expression of caveolin (CAV)1 in the development of renal cell cancer (RCC) and to determine a possible prognostic relevance for optimal clinical management.
  
  
  METHODS
  109 RCC and 81 corresponding normal tissue specimens from the same kidney were collected from patients undergoing surgery for renal tumors and subjected to total RNA extraction. Quantification of CAV1 mRNA expression was performed using real-time reverse transcription PCR with three endogenous controls for renal proximal tubular epithelial cells and the ΔΔCt method for calculation of relative quantities. Expression levels were correlated to clinical variables.
  
  
  RESULTS
  Tissue-specific mean CAV1 expression was significantly increased in RCC compared with normal renal tissue (p = 0.0003; paired Wilcoxon rank sum test). CAV1 expression was increased 1.9-fold in clear cell RCC compared with papillary RCC (p = 1.48 × 10(-7); unpaired Wilcoxon rank sum test). Patients with advanced disease had higher CAV1 expression when compared with organ-confined disease (p = 0.019; unpaired Wilcoxon rank sum test). Moreover, mean tissue-specific CAV1 expression was increased in patients with distant metastasis at the time of diagnosis compared with patients without metastasis (p = 0.0058; unpaired Wilcoxon rank sum test).
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to show that CAV1 mRNA expression, using quantitative real-time PCR, is significantly higher in RCC compared with normal renal tissue and increases with tumor stage. CAV1 mRNA expression might serve as a candidate biomarker for objective prognosis indicating RCC aggressiveness. Our data encourage further investigations to determine the role of CAV1 in RCC.
authors.affiliation: Department of Urology, Hannover Medical School, Germany. waalkes.sandra@mh-hannover.de
authors.forename: Sandra
authors.initials: S
authors.lastname: Waalkes
authors.forename: Hendrik
authors.initials: H
authors.lastname: Eggers
authors.forename: Hanna
authors.initials: H
authors.lastname: Blasig
authors.forename: Faranaz
authors.initials: F
authors.lastname: Atschekzei
authors.forename: Mario W
authors.initials: MW
authors.lastname: Kramer
authors.forename: Jörg
authors.initials: J
authors.lastname: Hennenlotter
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Tränkenschuh
authors.forename: Arnulf
authors.initials: A
authors.lastname: Stenzl
authors.forename: Jürgen
authors.initials: J
authors.lastname: Serth
authors.forename: Andres J
authors.initials: AJ
authors.lastname: Schrader
authors.forename: Markus A
authors.initials: MA
authors.lastname: Kuczyk
authors.forename: Axel S
authors.initials: AS
authors.lastname: Merseburger
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D051242:Caveolin 1 / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C495540:CAV1 protein, human; D051242:Caveolin 1; D012333:RNA, Messenger