title: Human glandular kallikrein 2 expression in prostate adenocarcinoma and lymph node metastases.
abstract: OBJECTIVE
  To describe the expression of a potential new tumor marker, human glandular kallikrein 2 (hK2), in primary adenocarcinoma and lymph node metastases that may be useful as an adjunct to prostate-specific antigen (PSA) in the diagnosis and monitoring of prostate cancer.
  
  
  METHODS
  We evaluated 151 radical prostatectomy specimens removed at Mayo Clinic with node-positive adenocarcinoma to compare cytoplasmic expression of hK2, pro-hK2, and PSA in benign tissue, prostate adenocarcinoma, and lymph node metastases. Monoclonal antibodies for mature hK2 (hK2-G586), pro-hK2 (pro-hK2-G464), and PSA (PSA-773) were used. A polyclonal antibody for PSA was also used. Immunoreactivity in each case was tested to determine whether cancer recurrence could be predicted.
  
  
  RESULTS
  Intense epithelial cytoplasmic immunoreactivity was observed in every case for hK2-G586, pro-hK2-G464, PSA-773, and polyclonal PSA (100% of cases, respectively). The intensity and extent of hK2 expression was greater in lymph node metastases than in primary cancer; furthermore, the expression in primary cancer was greater than in benign epithelium. Pro-hK2 was expressed in a greater percentage of cells in primary cancer than in benign tissue; furthermore, pro-hK2 was expressed to a greater extent in primary cancer than in lymph node metastases. In marked contrast to mature hK2, monoclonal PSA immunoreactivity was expressed to a higher extent in primary cancer than in lymph node metastases. Polyclonal PSA showed an incremental increase in expression from benign tissue to primary cancer and a further increase in expression in lymph node metastases.
  
  
  CONCLUSIONS
  hK2 was expressed in every cancer, and the expression incrementally increased from benign epithelium to primary cancer and lymph node metastases. Pro-hK2 was expressed to the greatest extent in primary cancer. Monoclonal PSA displayed inverse immunoreactivity compared with hK2. Polyclonal PSA showed incremental increases, suggesting that both hK2 and PSA were being detected. Tissue expression of hK2 appears to be regulated independently of PSA in benign epithelium, adenocarcinoma, and lymph node metastases.
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Darson
authors.forename: A
authors.initials: A
authors.lastname: Pacelli
authors.forename: P
authors.initials: P
authors.lastname: Roche
authors.forename: H G
authors.initials: HG
authors.lastname: Rittenhouse
authors.forename: R L
authors.initials: RL
authors.lastname: Wolfert
authors.forename: M S
authors.initials: MS
authors.lastname: Saeid
authors.forename: C Y
authors.initials: CY
authors.lastname: Young
authors.forename: G G
authors.initials: GG
authors.lastname: Klee
authors.forename: D J
authors.initials: DJ
authors.lastname: Tindall
authors.forename: D G
authors.initials: DG
authors.lastname: Bostwick
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000378:metabolism* / Q000556:secondary*; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D007610:Kallikreins / Q000032:analysis / Q000096:biosynthesis*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000096:biosynthesis; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D020840:Tissue Kallikreins
chemical_list: D014408:Biomarkers, Tumor; D007610:Kallikreins; D020840:Tissue Kallikreins; D017430:Prostate-Specific Antigen