A fluorescent orthotopic bone metastasis model of human prostate cancer.

Here, we report a fluorescent spontaneous bone metastatic model of human prostate cancer developed by surgical orthotopic implantation of green fluorescent protein (GFP)-expressing prostate cancer tissue. Human prostate cancer PC-3 cells were transduced with the pLEIN expression retroviral vector containing the enhanced GFP and neomycin resistance genes. Stable GFP high-expression PC-3 clones were selected in vitro with G418, which were then combined and injected s.c. in nude mice. For metastasis studies, fragments of a single highly fluorescent s.c. growing tumor were implanted by surgical orthotopic implantation in the prostate of a series of nude mice. Subsequent micrometastases and metastases were visualized by GFP fluorescence throughout the skeleton, including the skull, rib, pelvis, femur, and tibia The central nervous system, including the brain and spinal cord, was also involved with tumor, as visualized by GFP fluorescence. Systemic organs, including the lung, plural membrane, liver, kidney, and adrenal gland, also had fluorescent metastases. The metastasis pattern in this model reflects the bone and other metastatic sites of human prostate cancer. Thus, this model should be very useful for the study and development of treatment for metastatic androgen-independent prostate cancer.