Figure 5. MiR-339-5p inhibits the growth of HCT116 xenograft tumors in a largely p53-dependent manner.

(A, B) MiR-339-5p inhibited the growth of HCT116 xenograft tumors in nude mice in a largely p53-dependent manner. Xenograft tumors were established by s.c. injection of HCT116 p53+/+ and HCT116 p53−/− cells into nude mice. When tumor volumes reached ~60mm³, tumors were injected with miR-339-5p mimic or miR-con once every two days for 6 times. (A) Representative tumors were photographed at 12 days after the first treatment with miR-339-5p mimic or miR-con. Scale bar: 10 mm. (B) Upper panels: The growth curves of HCT116 p53+/+ and p53−/− tumors after miR-339-5p injection. The relative volumes of the tumors before treatment at day 0 were designated as 1. Lower panel: The fold reduction of tumor volumes by miR-339-5p injection in both HCT116 p53+/+ and p53−/− tumors. Data are presented as mean ± SD (n=12 for each group). *: p<0.01; **: p<0.001; two-tailed Student t-tests. (C) Injection of miR-339-5p reduced MDM2 protein levels and increased p53 protein levels in HCT116 xenograft tumors. Six tumors from each group were used for western-blot analysis, and very similar results were observed. Represented are 2 tumors from each group.