Figure 4

Analysis of NB1691 ^luc and SK-N-AS ^luc xenografts. MiR-34a or premiR-negative control-treated SK-N-AS^luc and NB1691^luc cells (4.4 × 10⁵), which were stably transfected with luciferase, were introduced into the retroperitoneal space of CB17-SCID immunocompromised mice (n = 4-7). Animals were administered an intraperitoneal injection of D-Luciferin (150 mg/kg) and, five minutes after substrate injection, the animals were imaged using an IVIS Imaging System 100 Series (Xenogen Corporation, Alameda, CA). Imaging was carried out at days 6, 10, 14 and 21 post-tumor cell inoculation and the data analysed and presented as the mean value for each cohort (photons/sec/cm²) ± SEM (*p < 0.001 and **p < 0.0001). The bioluminescent images above are representative of the photons/sec/cm² values obtained in premiR-negative control-treated SK-N-AS^luc (Figure 4A and C) and NB1691^luc (Figure 4B and D) animals compared to miR-34a-treated groups. Pre-treatment of both SK-N-AS^luc and NB1691^luc cells with synthetic miR-34a lead to significant reduction in tumor volume relative to premiR-negative control-treated cell tumors. Animals were sacrificed at moribundity and Mantle-Cox analysis was used to compare overall survival in xenograft cohorts (Figure 4E represents SK-N-AS^luc and Figure 4F represents the data obtained for NB1691^luc animals, p < 0.003 for both murine models).