Fig. 5.

BI 853520 represses outgrowth of pulmonary metastases. a Top panel: Schematic overview of the experimental setup. Mice were either pre-treated with BI 853520 3 days prior to 4T1 orthotopic tumor cell inoculation (Vehicle-PRE or BI 853520-PRE groups) or treated 7 days post 4T1 orthotopic tumor cell injection (Vehicle-POST or BI 853520-POST groups). Left bottom panel: Primary tumor growth in the indicated treatment cohorts was monitored over time. BI 853520 treatment (BI 853520-PRE and BI 853520-POST) significantly reduced primary tumor growth. Middle bottom panel: Average numbers of individual pulmonary metastases per lung section. Only pre-treatment with BI 853520 decreased the numbers of pulmonary metastases. Right bottom panel: Average metastatic area fraction (%) in pulmonary cross sections. Only pre-treatment with BI 853520 decreased the outgrowth of pulmonary metastases. n = 9, Vehicle-PRE; n = 9, BI 853520-PRE; n = 8, Vehicle-POST; n = 8, BI 853520-POST. Statistical analysis was performed by unpaired, two-tailed Mann–Whitney U test (for tumor volumes) or unpaired, two-tailed Student’s t test (for number metastases/section and metastasis area fraction). b Top panel: Schematic overview of the experimental setup. Mice were either pre-treated with BI 853520 3 days prior intravenous injection of 4T1 cells (Vehicle-PRE or BI 853520-PRE groups) or treated 3 days post intravenous injection of 4T1 cells (Vehicle-POST or BI 853520-POST groups). Left bottom panel: Average numbers of pulmonary metastases per lung section. BI 853520 pre-treatment significantly decreased pulmonary metastases. Right bottom panel: Average metastatic area fraction (%) in pulmonary cross-sections. Both BI 853520 treatments (BI 853520-PRE and BI 853520-POST) significantly reduced the metastatic area fraction. n = 5 for all treatment cohorts. Statistical analysis was performed using unpaired, two-tailed Student’s t test. c Schematic overview of the experimental setup. 4T1 cells were orthotopically transplanted into the mammary fat pad, followed by primary tumor removal 14 days post-injection and BI 853520 therapy in an adjuvant setting 2 days post surgery. Mice were sacrificed 38 days post injection. Left bottom panel: Average numbers of pulmonary metastases per lung section in an adjuvant BI 853520 setting. BI 853520 significantly increased the number of pulmonary metastases. Right bottom panel: Average metastatic area fraction (%) in pulmonary cross-sections, with a trend of decrease following adjuvant BI 853520 therapy. n = 7, Vehicle; n = 5, BI 853520. Statistical analysis was performed using unpaired, two-tailed Student’s t test. d Schematic overview of the experimental setup. 4T1 cells were orthotopically transplanted into the mammary fat pad, followed by neoadjuvant BI 853520 therapy. Primary tumors were removed 14 days post injection and BI 853520 therapy was discontinued. Mice were sacrificed 32 days post injection. Left bottom panel: Primary tumor volumes. Right bottom panel: Number of metastatic lesions per mouse. n = 5, Vehicle; n = 5, BI 853520. Statistical analysis was performed by Mann–Whitney U test for tumor volumes and Student’s t test for lung metastases. ****p < 0.0001, ***p < 0.001. ns not significant