title: Leptin and leptin receptor expressions in prostate tumors may predict disease aggressiveness?
abstract: OBJECTIVE
  The aim of this study was to evaluate the expression of leptin and its receptor in histological sections of prostate tumors, and their association with prognostic factors.
  
  
  METHODS
  A total of 532 surgical specimens from prostate cancer were studied. After histopathological diagnosis, the samples were included in tissue microarrays containing cores from tumor and non-tumor (benign prostatic hyperplasia) areas. These were immunostained with anti-leptin and anti-leptin-receptor antibodies. Objective and subjective analyses were performed. Student's-t-test and ANOVA were used to compare mean values, and linear regression was used to evaluate the correlation between histological results and prognostic indicators.
  
  
  RESULTS
  Leptin receptor expression was reduced in tumors with a positive surgical margin, urethral margin involvement, and seminal vesicles invasion. Further, there was a negative correlation between the expression of leptin receptor in tumor areas and the sum of prognostic factors, suggesting that leptin receptor may predict the aggressiveness of disease.
  
  
  CONCLUSIONS
  Our findings suggest that leptin receptor expression is a potential prognostic factor for PCa. Further investigation is needed to support the use of leptin receptor as a novel biomarker, although leptin itself does not seem to predict the aggressiveness of prostate cancer.
authors.affiliation: State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Clarice F
authors.initials: CF
authors.lastname: Osório
authors.affiliation: State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Diogo B de
authors.initials: DB
authors.lastname: Souza
authors.affiliation: State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Carla B M
authors.initials: CB
authors.lastname: Gallo
authors.affiliation: State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Waldemar S
authors.initials: WS
authors.lastname: Costa
authors.affiliation: State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Francisco J B
authors.initials: FJ
authors.lastname: Sampaio
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D018450:Disease Progression; D006801:Humans; D020738:Leptin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D054411:Receptors, Leptin / Q000378:metabolism*; D012669:Seminal Vesicles / Q000473:pathology; D046888:Tissue Array Analysis
chemical_list: D015415:Biomarkers; D020738:Leptin; D054411:Receptors, Leptin