title: Loss of CD10 (neutral endopeptidase) is a frequent and early event in human prostate cancer.
abstract: BACKGROUND
  We hypothesized that the aggressive LNCaP-derived androgen-independent cell line, CL1, might differ from LNCaP in their repertoire of cell surface markers and that these differences might typify changes that occur during clinical prostate cancer progression.
  
  
  METHODS
  The cell surface marker expression profiles of CL1 and LNCaP were examined using flow cytometry. Markedly differential gene expression was confirmed using RT-PCR and further examined using immunohistochemistry among the prostate cancer cell lines LAPC-4, LNCaP, CL1, CL2, DU145, and PC-3. The expression of the most markedly differentially expressed surface marker, CD10, was further explored in a tissue microarray containing radical prostatectomy samples from 219 hormone naïve prostate cancer patients.
  
  
  RESULTS
  There were marked differences in the expression of CD10, CD13, CD26, CD33, CD44, CD54, CD55, and CD104 between CL1 and LNCaP. Results from both the RT-PCR and immunohistochemistry confirmed the differential expression and found that CD10 demonstrated a pattern of expression in hormone sensitive but not hormone refractory cell lines. When CD10 expression was examined in a tissue microarray, CD10 expression was below the 25th percentile of matched normal prostate tissue in 68% of prostate cancers, below the median expression of matched normal prostate tissue in 86% of cancers, and completely absent in 34% of cancers. Samples of prostatic intraepithelial neoplasia demonstrated CD10 expression that was intermediate between normal prostatic tissue and prostate cancer. Among prostate cancer patients, CD10 expression did not correlate with Gleason score, pathological stage, or biochemical recurrence following radical prostatectomy.
  
  
  CONCLUSIONS
  These findings demonstrate that loss or decreased expression of CD10 is an early and frequent event in human prostate cancer and implicates CD10 as a potential therapeutic target for early stage hormone sensitive prostate cancer.
authors.affiliation: Department of Urology, UCLA School of Medicine, Los Angeles, CA 90095-1738, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
authors.forename: David B
authors.initials: DB
authors.lastname: Seligson
authors.forename: Alvin Y
authors.initials: AY
authors.lastname: Liu
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Pantuck
authors.forename: Sun H
authors.initials: SH
authors.lastname: Paik
authors.forename: Steve
authors.initials: S
authors.lastname: Horvath
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Wieder
authors.forename: Amnon
authors.initials: A
authors.lastname: Zisman
authors.forename: David
authors.initials: D
authors.lastname: Nguyen
authors.forename: Cho-Lea
authors.initials: CL
authors.lastname: Tso
authors.forename: Aarno V
authors.initials: AV
authors.lastname: Palotie
authors.forename: Arie S
authors.initials: AS
authors.lastname: Belldegrun
mesh_terms: D000368:Aged; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D015260:Neprilysin / Q000096:biosynthesis* / Q000235:genetics; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D040081:Protein Array Analysis; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D012334:RNA, Neoplasm; D015260:Neprilysin