Figure 6.

RARRES2 overexpression inhibits tumor growth in an NSG mice xenograft model. (a) The tumor growth curve in NSG mice. RARRES2 overexpression resulted in a significant growth inhibition as compared to the vector group starting from 3 weeks after xenograft. Each group contains seven mice / fourteen xenografts, but in the RARRES2 group, one xenograft never developed a measurable tumor, thus was excluded. Data were presented as mean ± SEM. *, P < 0.0001, **, P < 0.005, ***, P < 0.05. (b) The tumors isolated from each group at the time of sacrifice (8 weeks after xenograft). Left panel, pictures of all the tumors isolated from each group. Right panel, the tumor weight in each group. (c) The correlation between tumor volume and tumor weight for all tumors isolated (n = 27). r, correlation coefficient. (d) The human RARRES2 gene expression level in tumors isolated as measured by TaqMan qPCR. *, P < 0.0001. (e) RARRES2 protein level comparison between normal human adrenocortical tissues and NSG mice xenograft overexpressing RARRES2. Left panel, Western blotting result of protein expression in three human normal adrenocortical tissues and six RARRES2-overexpressing NSG mice tumor xenograft samples. Right panel, densitometry analysis of the Western blot for RARRES2/GAPDH ratio. ns, not significant. (f) The mouse CMKLR1 gene expression level in tumors isolated. Note that the expression level is presented as the percentage of gene expression of the mouse housekeeping gene Gusb. ns, not significant. (b), (d) and (f), Vector, n = 14; RARRES2, n = 13. (g) RARRES2 expression was associated with reduced p-p38 and total β-catenin levels. Left panel, Western blotting performed in seven tumors from the vector group, and six tumors from the RARRES2 group. Arrow head points to the p-p38 band. Right panel, quantification of Western blot images. *, P < 0.01; **, P < 0.05.