Figure 5. The miR-198 and -206 reduce the metastatic spreading of osteosarcoma in a HOS LucF-GFP xenograft model and prolong cancer-specific survival.

(A) Experimental design: 1.5 million HOS LucF-GFP Osteosarcoma cells were paratibially injected in nude mice. Three groups of eight mice were then randomly assigned and each one was intra-tumorally injected with either the Pre-miR Ct, the -198 or the -206 ones three times a week since the tumor volumes reached 100 mm³. The tumor growth was monitored until the time of the euthanasia, when the tumors were approximately 3000 mm³. At this time, the lungs were dissected and subjected to a luciferase-monitored counting of the metastases. (B) The mean tumor volume of the treated-mice was compared with control group ± s.e.m. (n = 8 mice in each group). A Two-way ANOVA statistical test was used to compare the effect of the different miRNAs on the tumor growth. (C) In Kaplan–Meier curves, cancer-specific survival were compared between mice treated with Pre-miR Ct, Pre-miR-198 and -206. The log-rank (Mantel-Cox) test was used to compare the overall survival between the three groups. (D) Histograms represent the percentage of the lung metastases-bearing mice depending on the treatment-groups. (E) Histograms show the average number of metastases counted thanks to luciferase-monitoring in each group of mice. Representative overlay illustrating pictures were presented. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001.