title: Aquaporin-1 protein levels elevated in fresh urine of renal cell carcinoma patients: potential use for screening and classification of incidental renal lesions.
abstract: OBJECTIVE
  There are over 65,000 new cases of renal cell carcinoma (RCC) each year, yet there is no effective clinical screening test for RCC. A single report claimed no overlap between urine levels of aquaporin-1 (AQP1) in patients with and without RCC (Mayo Clin Proc. 85:413, 2010). Here, we used archived and fresh RCC patient urine to validate this report.
  
  
  METHODS
  Archived RCC, fresh prenephrectomy RCC, and non-RCC negative control urines were processed for Western blot analysis. Urinary creatinine concentrations were quantified by the Jaffe reaction (Nephron 16:31, 1976). Precipitated protein was dissolved in 1x SDS for a final concentration of 2  μg/µL creatinine.
  
  
  RESULTS
  Negative control and archived RCC patient urine failed to show any AQP1 protein by Western blot analysis. Fresh RCC patient urine is robustly positive for AQP1. There was no signal overlap between fresh RCC and negative control, making differentiation straightforward.
  
  
  CONCLUSIONS
  Our data confirms that fresh urine of patients with RCC contains easily detectable AQP1 protein. However, archival specimens showed an absence of detectable AQP1 indistinguishable from negative control. These findings suggest that a clinically applicable diagnostic test for AQP1 in fresh urine may be useful for detecting RCC.
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Sreedharan
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA ; Atlanta VA Medical Center, 1670 Clairmont Rd, Decatur, GA 30033, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Petros
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: Viraj A
authors.initials: VA
authors.lastname: Master
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Ogan
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Pattaras
authors.affiliation: Department of Medicine, Emory University, 1525 Clifton Road, 423 Atlanta, GA 30322, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Roberts
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Lian
authors.affiliation: Department of Urology, Emory University, 1365 Clifton Road NE, Clinic B 4221, Atlanta, GA 30322, USA.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Arnold
mesh_terms: D000328:Adult; D000368:Aged; D051398:Aquaporin 1 / Q000652:urine*; D014408:Biomarkers, Tumor / Q000652:urine*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000652:urine*; D016022:Case-Control Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000652:urine*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: C496020:AQP1 protein, human; D014408:Biomarkers, Tumor; D051398:Aquaporin 1