2.5. Xenograft model

PCa cells (3 ×10⁶ cells/site) mixed with Matrigel (BD Biosciences) were injected subcutaneously into right and left leg of NOD/SCID mouse. For LNCaP xenograft, un-castrated mice were used whereas castrated mice were used for 22Rv1 and VCaP xenografts. Once tumor becomes palpable, tumor volume (mm³) was measured every 3 days with caliper and was calculated using the ellipsoid formula (π/6 x length x width x depth). For drug treatment, mice bearing palpable xenografts were randomized into different groups treated with vehicles and various drug/drug combination as indicated. Drugs were administered using minipump continuously for 7 days (for VCaP xenograft) or intraperitoneal injection with 3 times/week for 2 weeks at dose indicated (for 22Rv1 xenograft). Tumors were excised and weighted at time of sacrifice and used for target validation. All animal protocols were approved by the Institutional Animal Care and Use Committee in UT Southwestern Medical Center. Only male mice were used since prostate cancer is male-only disease.