title: Human kallikrein-related peptidase 12: antibody generation and immunohistochemical localization in prostatic tissues.
abstract: BACKGROUND
  Human tissue kallikrein-related peptidases (genes, KLKs; proteins, KLKs) are a subgroup of serine proteases present in a variety of tissues and biological fluids. A number of human tissue KLKs are established or candidate serologic biomarkers for prostate cancer. Human kallikrein-related peptidase 12 (KLK12, KLK12), recently identified in our laboratory, is a novel member of the KLK gene family. Here, we report generation of antibodies against the full-length recombinant KLK12 (classical form) and the immunohistological localization of this KLK in normal and malignant prostate tissues.
  
  
  METHODS
  The mature form of KLK12 cDNA was amplified using PCR and cloned into a plasmid vector for protein production in E. coli. Following identification by mass spectroscopy, recombinant KLK12 was purified and used as immunogen in rabbits. Anti- KLK12 antibody was used for immunostaining of paraffin-embedded sections of human prostate tissue. Immunoexpression of KLK12 in benign and malignant prostate tissue was evaluated using a prostate cancer tissue array.
  
  
  RESULTS
  Anti-KLK12 antibody showed a predominantly apical and membranous staining of the luminal cells of the normal prostate in contrast with the predominantly diffuse cytoplasmic staining observed in both prostatic intra-epithelial neoplasia and adenocarcinomas. This was occasionally associated with an intense granular supranuclear staining. More than 95% of the prostate cancers on the tissue microarray were KLK12 positive.
  
  
  CONCLUSIONS
  Higher levels of KLK12 in malignant prostatic glands, and the shift in subcellular localization of KLK12 in prostate cancer observed in this study point to the potential role of this kallikrein during prostate carcinogenesis.
authors.affiliation: Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Nader
authors.initials: N
authors.lastname: Memari
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
authors.forename: Tammy
authors.initials: T
authors.lastname: Earle
authors.forename: Alison
authors.initials: A
authors.lastname: Campbell
authors.forename: Herman
authors.initials: H
authors.lastname: Van Dekken
authors.forename: Theodore H
authors.initials: TH
authors.lastname: Van der Kwast
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics; D000912:Antibodies, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D015153:Blotting, Western; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007610:Kallikreins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008297:Male; D019048:Prostatic Intraepithelial Neoplasia / Q000201:enzymology* / Q000235:genetics; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis / Q000379:methods
chemical_list: D000912:Antibodies, Neoplasm; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; C497170:KLK12 protein, human; D007610:Kallikreins