Figure 2: In vivo treatment of Q2-3 significantly suppresses the metastasis of mouse (4T1) mammary tumour cells after a tumour resection process.

(a) Representative bioluminescent images of tumour-bearing mice (n=8 per group) after in vivo treatment with PBS (0.1% DMSO in saline), doxorubicin (2 mg kg⁻¹) or different dosages of Q2-3, after resection of the orthotopic primary tumours. In the PBS-treated group (vehicle), three mice died before 3 weeks post tumour resection. The red signal represents the highest level on the colorimetric scale. (b) Quantification of tumour metastasis by measuring luciferase activity in photons s⁻¹ cm⁻² sr⁻¹ in mice revealed along the indicated time course (n=8 per group). (c) Survival of test mice after different treatments. P<0.05, were obtained between the control (DMSO) and Q2-3-treated (20 or 100 μg kg⁻¹) groups (Kaplan–Meier results were analysed by log-rank test). (d) Effect of Q2-3 (2, 20 or 50 μg kg⁻¹) on the population change of monocytic (CD11b⁺Ly6C⁺) and granulocytic (CD11b⁺Ly6G⁺) MDSCs in lung tissues of test mice were quantified by flow cytometry analysis, and were compared with MDSC populations in PBS group. Data are reported as mean±s.d. (n=3). *P<0.05; **P<0.01; NS, not significant (two-tailed t-test). Similar results were obtained from three independent experiments.