Unusual behaviour of the LNCaP prostate tumour xenografted in nude mice.

The tumourigenicity of the LNCaP prostatic cell line was investigated in vivo after prostatic (orthotopic), subcutaneous (ectopic) and concomitant implantations in male Balb/c nude mice. Swollen lymph nodes were detected in the inguinal region only after subcutaneous implantation but could not be characterized by immunohistochemistry. However, when grafted to Endoxan-pretreated mice, they generated well differentiated tumours which secreted prostate-specific acid phosphatase. A parallel study was conducted to investigate the metastatic potential of the LNCaP tumour using several routes of implantation (intravenous, bone contact, intrasplenic and intracranial). Tumours grew only after intracranial implantation. No production of either haematogenous or bony metastases was recorded.