title: Association of legumain expression pattern with prostate cancer invasiveness and aggressiveness.
abstract: OBJECTIVE
  To investigate the clinical implication of legumain, an asparaginyl endopeptidase that is highly expressed in several types of cancer, expression in prostate cancer.
  
  
  METHODS
  Legumain expression in prostate cancer cell lines was determined by real-time reverse transcriptase PCR and Western blot. Furthermore, legumain expression in 88 prostatectomy specimens was evaluated by immunohistochemistry. The association between legumain expression and clinicopathological factors was analyzed.
  
  
  RESULTS
  Legumain expression was confirmed at the mRNA and protein levels in all the cells. Although all the cancer tissues were positive for legumain, 2 staining patterns were observed in the cytoplasm: diffuse cytoplasmic and vesicular positivity. The rates of Gleason score ≥8, extracapsular extension, and perineural invasion in the group with vesicular staining were significantly higher than those in the diffuse cytoplasmic group (p < 0.05). The maximum size of the tumor with vesicular staining was significantly greater than that of the tumor with diffuse cytoplasmic staining (p = 0.0302). The 5-year biochemical recurrence-free rate in the patients with vesicular legumain staining was 53.2%; this rate was significantly lower than that (78.8%) in the patients with diffuse cytoplasmic staining (p = 0.0269).
  
  
  CONCLUSIONS
  Tumors that showed a vesicular staining pattern of legumain had the potential of being highly invasive and aggressive in patients with prostate cancer who were treated with radical prostatectomy. This suggests that legumain might contribute to the invasiveness and aggressiveness of prostate cancer.
authors.affiliation: Department of Urology, Tokyo Medical University, 6-7-1, Nishishinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan. yoshio-o@tokyo-med.ac.jp
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ohno
authors.forename: Jun
authors.initials: J
authors.lastname: Nakashima
authors.forename: Miki
authors.initials: M
authors.lastname: Izumi
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohori
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tachibana
mesh_terms: D000368:Aged; D045744:Cell Line, Tumor; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000201:enzymology; D022162:Cytoplasmic Vesicles / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D011467:Prostate / Q000201:enzymology* / Q000378:metabolism; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000099240:Asparaginyl Endopeptidase
chemical_list: D003546:Cysteine Endopeptidases; D012333:RNA, Messenger; D000099240:Asparaginyl Endopeptidase