Comparison of two in vivo models for prostate cancer: orthotopic and intratesticular inoculation of LNCaP or PC-3 cells.
BACKGROUND
The critical events in the clinical course of prostate cancer are the occurrence of metastasis and the induction of the hormone-refractory status of the disease. In order to investigate the factors responsible for these events, we need appropriate in vivo models.


METHODS
Orthotopic and intratesticular models were created by the injection of LNCaP cells or PC-3 cells into the prostate or testis of severe combined immunodeficient mice.


RESULTS
LNCaP cells in the intratesticular model showed a higher incidence of tumor formation and lymph node metastasis when compared with those in the orthotopic model, while PC-3 cells were highly tumorigenic and metastastic in both models. A high concentration of androgens might play a role in tumor aggressiveness of LNCaP cells, given that enhanced mRNA expressions of integrin alphaV and vascular endothelial growth factor was induced by dehydrotestosterone administration in vitro. The high expression of metastasis-related genes, including the urokinase plasminogen activator system, metalloproteinases and vascular endothelial growth factor-C, might be attributed to the high metastatic potential in both models. Interestingly, testicular xenografts of LNCaP cells were able to survive on the subcutis back of castrated male mice as well female mice.


CONCLUSIONS
Intratesticular models of prostate cancer appear to be suitable for studying the mechanisms of metastasis and for evaluating various treatment strategies.
Koshida
Kiyoshi
K
Department of Urology, Graduate School of Medical Science, 13-1, Kanazawa University, Kanazawa-city, Ishikawa 920-8641, Japan. tak1019@kenroku.kanazawa-u.ac.jp
Konaka
Hiroyuki
H
Imao
Tetsuya
T
Egawa
Masayuki
M
Mizokami
Atsushi
A
Namiki
Mikio
M
D000818:Animals; D045744:Cell Line, Tumor / Q000637:transplantation*; D004195:Disease Models, Animal; D006801:Humans; D008297:Male; D051379:Mice; D016513:Mice, SCID; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D011467:Prostate / Q000601:surgery*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D013737:Testis / Q000601:surgery*; D014183:Transplantation, Heterologous
D009841:Oligonucleotides; D012333:RNA, Messenger