Figure 5.

Rb depletion desensitizes CRPC tumor response to high-T

(A and B) Xenograft tumors derived from C4-2-tet-shRB cells were established in castrated male SCID mice. Tumor-bearing mice fed with a regular diet (A) or a doxycycline-supplemented diet (B) were daily injected with vehicle or testosterone (40 mg/kg or 160 mg/kg). Tumor volume was measured manually by caliber (n = 6). Note: the two xenograft experiments were done independently. (C) Cell proliferation assay for control C4-2 cell line and two RB-KO cell lines treated with or without DHT (10 nM, 0–6 d) is shown. (D) Cell proliferation assay for control C4-2 cell line and RB-KO-3 cell line treated with or without DHT (0–1,000 nM, 0–5 d) is shown. (E) Xenograft tumors derived from RB-KO-3 line were established in castrated male SCID mice. Tumor-bearing mice were then daily injected with vehicle or testosterone (40 mg/kg or 160 mg/kg). Tumor volume was measured manually by caliber (n = 4). Data in growth curves represent the mean ± SE. n.s., not significant.