Growth of prostate tumors in immune-competent C57BL/6J mice and RSV-mediated apoptosis of prostate tumors in situ. (a) RM1 murine prostate cancer cell tumors, grown subcutaneously in C57BL/6J mice, were injected with RSV or medium (intratumoral). Each treatment group had four representative animals (n = 4) and data represent the normalized mean tumor volume trajectories over time. Tumor volume of each mouse was normalized against its tumor volume at day 1 of injection, which was set as 100%. Error bars represent SE of the mean. (b, c) TUNEL assay with prostate tumors derived from LNCaP (a) or RM1 (b) cells (at 100× magnifications). Tumors, injected with RSV or Medium (control), were excised, processed and tumor sections were analyzed by TUNEL assay. RM1 tumors were derived 12 h after two RSV injections (2 d apart) via intratumoral route. In contrast, LNCaP tumors were derived 12 h after three RSV injections (2 d apart) via intratumoral route.