Gene expression profiling study of VCaP xenograft tumors collected from intact and castrated athymic nude mice

The purpose of the study was to characterize the properties of human prostate cancer VCaP tumors pre- and post-castration. The main focus was on androgen signaling, androgen metabolism and steroid synthesis. Results provide valuable information about how castration-resistant tumors (CRPC) are able grow in absence of gonadal androgens. One million VCaP cells were inoculated orthotopically into the dorsolateral prostate of nude mice through an abdominal incision. Tumor growth was followed by serum PSA measurements. Intact mice were sacrificed and tumors were collected 3-14 weeks after inoculation (Intact 1, Intact 2). Mice in the remaining three groups (GNX, CRPC 1, CRPC 2) were castrated by removing the testes. Mice were sacrificed and tumors were collected one day after castration (GNX) or 3-14 weeks after castration (CRPC 1, CRPC 2) in castration-resistant stage. 4 tumors were selected from each study group, totally 20 tumors.