Visualization of advanced human prostate cancer lesions in living mice by a targeted gene transfer vector and optical imaging

Non-invasive imaging and transcriptional targeting can improve the safety of therapeutic approaches in cancer. Here we demonstrate the ability to identify metastases in a human-prostate cancer model, employing a prostate-specific adenovirus vector (AdPSE-BC-luc) and a charge-coupled device-imaging system. AdPSE-BC-luc, which expresses firefly luciferase from an enhanced prostate-specific antigen promoter, restricted expression in the liver but produced robust signals in prostate tumors. In fact, expression was higher in advanced, androgen-independent tumors than in androgen-dependent lesions. Repetitive imaging over a three-week period after AdPSE-BC-luc injection into tumor-bearing mice revealed that the virus could locate and illuminate metastases in the lung and spine. Systemic injection of low doses of AdPSE-BC-luc illuminated lung metastasis. These results demonstrate the potential use of a non-invasive imaging modality in therapeutic and diagnostic strategies to manage prostate cancer.