Figure 5.

Apelin is required for compact tumor growth. Mice were inoculated subcutaneously with U87 cells and grown for 28 dpi. (A) Tumor volumes were measured, and vessel density was quantified on CD31-immunostained sections. Representative pictures of subcutaneous tumors are shown. (B) VLD and tumor volume was significantly attenuated upon reduction of APLN expression as compared to U87^NSCAPLN^WT controls (percentages compared to the control group are indicated). Tumor volumes were reduced to 50% in APLN knockdown U87^AKDAPLN^WT xenografts. Further reduction to less than 15% was observed in APLN^KO mice. Number of cell implantations for U87^NSCAPLN^WT, U87^AKDAPLN^WT, U87^NSCAPLN^KO, U87^AKDAPLN^KO were n = 38, 31, 18, 24, while tumor take was 87%, 90% 72%, 50%, respectively. For VLD analysis n = 7, 6, 7, 6 of the respective xenografts were analyzed. Data are reported as mean +/−SEM; statistical significance (one-way ANOVA plus Bonferroni’s post hoc test) is indicated * p < 0.05, ** p < 0.005, *** p < 0.0005.