Figure 4.

Effect of treatment with Debio-0719 on tumor proliferation in the 4T1 spontaneous metastasis mouse model. The primary tumor and liver and lung tissues from the mice used in experiments described in Figure 2, B–E were analyzed for Ki67 as a marker of dormancy. Tissue sections from the (A) primary tumors and (B) metastases in the liver (indicated by white dotted lines) from mice injected with 4T1 cells and treated with either vehicle control or Debio-0719 (15mg/kg administered subcutaneously twice daily) underwent immunofluorescence staining for Ki67 (green). Tumor nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI, blue). The mean expression levels of Ki67 (n = 5 mice per group) were determined and were calculated as the mean ratio of Ki67 to DAPI. Corresponding 95% confidence intervals are indicated by the whisker bars. Representative images are shown. *P =.005 compared with the vehicle control-treated mice and was determined by a two-sided t test. Scale bar = 220 µm.