c-Met inhibitor combined with castration reduced proliferation of castration resistant prostate cancer cells in vivo. LNCaP cells were orthotopically implanted into the prostates of male SCID mice supplemented with testosterone (see "Materials and Methods"). (A) Prostate tissue isolated from a representative non-castrated 11 week-old male SCID mouse and analyzed with hematoxylin and eosin staining and immunohistochemistry with the human AR antibody or PSA antibody. (B) Prostate tissue stained with hematoxylin and eosin, human AR antibody, and PSA antibody that was isolated from a representative 15 week-old male SCID mouse that had been castrated at 11 weeks-old. (C) Representative prostate tissue analyzed with Ki67 antibody that was isolated from castrated animals that were given either water (left) or PF-2341066 at 50 mg/kg (right) for 4 weeks post-castration. (D) Ki67 index was measured in pre-castration, control castrated mice on water, and castrated mice treated with PF-2341066. There was a significant difference between control and treated mice, *P < 0.01 (Student's t test).