title: Osteopontin expression in prostate cancer and benign prostatic hyperplasia.
abstract: OBJECTIVE
  Osteopontin (OPN), a secreted adhesive glycoprotein, has been shown to be produced in excessive amounts in a variety of experimental models of malignancy. Increased levels of OPN exist in blood from the lungs, breasts, and gastrointestinal tracts of cancer patients with metastases. However, there have been no reports on the expression of OPN in human urological malignancies. The present study investigates the presence of OPN in adenocarcinoma of the human prostate and in benign prostatic hyperplasia (BPH).
  
  
  METHODS
  Using prostate tissue from 34 patients with primary prostate cancer, 13 patients with prostate cancer after having undergone hormonal therapy, and 12 patients with BPH, formalin-fixed paraffin sections were prepared. Specimens were obtained by needle biopsy or radical prostatectomy. Immunohistochemical staining (ABC method) was then performed. Staining was divided into either negative or positive categories.
  
  
  RESULTS
  Positive staining of OPN was observed on cancer cells and macrophages in 52.9% of the primary prostate cancers and 14.5% of the prostate cancers after hormonal therapy. In BPH specimens, 66.7% of the cases displayed positive staining of OPN. The staining level of OPN showed no correlation with serum prostate-specific antigen, but did correlate with stage, differentiation, and Gleason's score.
  
  
  CONCLUSIONS
  The result postulates that the expression of OPN is an indicator of cell differentiation; however, it cannot be used as a marker of malignancy in prostate cancer.
authors.affiliation: Department of Urology, Nagoya City University Medical School, Nagoya, Japan. toza@med.nagoya-cu.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Tozawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
authors.forename: N
authors.initials: N
authors.lastname: Kawai
authors.forename: T
authors.initials: T
authors.lastname: Okamura
authors.forename: K
authors.initials: K
authors.lastname: Ueda
authors.forename: K
authors.initials: K
authors.lastname: Kohri
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D053495:Osteopontin; D010750:Phosphoproteins / Q000096:biosynthesis*; D011467:Prostate / Q000737:chemistry; D011470:Prostatic Hyperplasia / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000096:biosynthesis*
chemical_list: D010750:Phosphoproteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin