title: The expression of pigment epithelium-derived factor in bladder transitional cell carcinoma.
abstract: BACKGROUND
  Pigment epithelium-derived factor (PEDF) is an anti-angiogenic factor. The purpose of this study is to examine the involvement of PEDF in the angiogenesis and biological behavior of bladder transitional cell carcinoma (TCC).
  
  
  METHODS
  We examined the expression of PEDF in 99 bladder TCCs and ten non-neoplastic tissues, and evaluated microvessel density (MVD).
  
  
  RESULTS
  The positive immunoreactivity for PEDF was seen in normal urothelium in 60% (6/10) and TCC in 13% (13/99). The PEDF expression had a significant correlation with MVD, i.e., a low MVD in 42% (5/12), a middle MVD in 11% (8/76) and a high MVD 0% (0/11) of tumors. The PEDF expression was not significantly correlated with the differentiation and invasion of TCC, but the degree of MVD was significantly higher in both high grade TCC and the pT2 tumors.
  
  
  CONCLUSIONS
  The degree of PEDF expression is significantly higher in normal bladder urothelium than bladder TCC; it is inversely correlated with the angiogenesis; and it is not related to the differentiation and progression of TCC. It can therefore be concluded that bladder TCC would initially occur if there is a lack of the PEDF expression.
authors.affiliation: Department of Pathology, Dongguk University College of Medicine, Gyeongju, Korea.
authors.forename: Tae Jung
authors.initials: TJ
authors.lastname: Jang
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Kyung Seop
authors.initials: KS
authors.lastname: Lee
keywords: Angiogenesis; Bladder transitional cell carcinomas; Pigment epithelium-derived factor