title: Metastatic model for human prostate cancer using orthotopic implantation in nude mice.
abstract: BACKGROUND
  Understanding the mechanism of prostate cancer metastasis is essential to the design of a more effective therapy. An effective therapy for this disease will depend on the development of a clinically relevant in vivo model.
  
  
  OBJECTIVE
  We describe the development of such a model by using orthotopic implantation of human prostate cells in BALB/c nude mice.
  
  
  METHODS
  We compared the tumorigenicity of and the incidence of metastasis of human prostate cancer PC-3M and LNCaP-FGC (LNCaP) cell lines subsequent to prostatic (orthotopic) or subcutaneous (ectopic) implantations in male nude mice.
  
  
  RESULTS
  LNCaP cells produced tumors only in the prostate. Enhanced tumorigenicity at the orthotopic site was found for PC-3M cells. Lymph node metastases were observed in practically all mice given an injection of PC-3M cells in the prostate, but they were uncommon with subcutaneous injection of these cells. Bilateral orchiectomy did not alter the tumorigenicity of either PC-3M or LNCaP cells or the incidence of lymph node metastasis by PC-3M cells. LNCaP tumors in the mouse prostate (but not PC-3M tumors) elaborated detectable levels of human prostate-specific antigen (PSA) in the serum, even when tumors were small (1.5 mm in diameter). Immunohistochemistry analysis revealed the presence of the PSA marker in tissue sections of LNCaP but not of PC-3M tumors.
  
  
  CONCLUSIONS
  The implantation of human prostate cancer cells in an ectopic environment does not permit expression of metastatic potential. In contrast, intraprostatic implantation does.
  
  
  CONCLUSIONS
  These data suggest that the orthotopic injection of human prostate cancer cells into the nude mouse may provide a valuable model to study the biology and therapy of human prostate cancer.
authors.affiliation: Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston 77030.
authors.forename: R A
authors.initials: RA
authors.lastname: Stephenson
authors.forename: C P
authors.initials: CP
authors.lastname: Dinney
authors.forename: K
authors.initials: K
authors.lastname: Gohji
authors.forename: N G
authors.initials: NG
authors.lastname: Ordóñez
authors.forename: J J
authors.initials: JJ
authors.lastname: Killion
authors.forename: I J
authors.initials: IJ
authors.lastname: Fidler
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000097:blood; D004195:Disease Models, Animal; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D003012:Microbial Collagenase / Q000096:biosynthesis; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000473:pathology*; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms / Q000097:blood / Q000201:enzymology / Q000473:pathology*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen; D003012:Microbial Collagenase