Fig. 6

In vivo Blockade of ERK1/2 with SCH772984 reduces CTC number and BC metastasis. Note: Mice were randomly divided into 5 batches, recorded as batch 1, batch 2, batch 3, batch 4, batch 5. Each batch divided again into 3 experimental groups, CtrL-vehicle, FOXD1-vehicle and FOXD1-SCH. The observation times of 5 batches were 1, 3, 5, 7, 9 weeks respectively. For batch 1–4, CTC capture and xenograft tumors isolation analyses were performed on each mouse (3 mice/group). For batch 5, continuously BLI (from week 1 to 9), CTC capture, xenograft tumors isolation and BLI of lungs analyses were performed on each mouse (5 mice/group). A Schematic view of SCH772984 treatment xenograft model. Control or FOXD1 overexpression MDA231 cells were injected into mammary fat pad. After the tumor volume reached approximately 50 mm3, SCH772984 were diluted in DMSO and were delivered through intraperitoneal injection twice a day with a concentration of 25 mg/kg for each mouse. B The CTC numbers of the indicated group at each time point. At each observation time point, the CTC number of 3 mice in each group (CtrL-vehicle, FOXD1- vehicle, FOXD1-SCH) were respectively detected. The blood samples were retrieved via cardiac puncture. Error bars, SEM. n = 3. **p<0.01, ***p < 0.001 by Student’s t-test. C BLI of lungs at the last observation time point (batch 5). Error bars, SEM. **p<0.01 by Student’s t-test. D BLI was continuously performed on the mice of batch 5. Representative images of BLI at week 1, 3, 5, 7, 9 after control or FOXD1 overexpression MDA231 cells were injected into mammary fat pad. Error bars, SEM. **p < 0.01 by Student’s t-test. E Images of all xenograft tumors isolated from each indicated batch. Error bars, SEM. *p<0.05, **p < 0.01 by Student’s t-test. F IHC analyzed the expression FOXD1, RalA, p-ERK1/2, and Vimentin in the xenograft tumor from mouse models at the last time point (week 9). Scale bar, 50 μm. Error bars, SD. n = 3. *p<0.05, **p < 0.01, ***p < 0.001 by Student’s t test. ns. = not significant. G A schematic model of the FOXD1-dependent RalA-ANXA2-Src complex promoting CTC formation and metastasis via activating ERK1/2 signal regulatory cascade in BC