Figure 4. Efficacy of S. typhimurium A1-R on the growth of 4T1-RFP brain metastases and mouse survival.

(A) Nude mice with brain metastatic 4T1-RFP two weeks after surgical removal of orthotopic primary tumor. Mice were injected i.v. with S. typhimurium A1-R (5 × 10⁷ CFU in 100 μl PBS). Tumors were visualized with the Maestro fluorescence imaging system at indicated time points after infection. (Upper row): S. typhimurium A1-R treated mice. (Lower row): Control mice. (B) Growth curve of brain metastasis in control and S. typhimurium A1-R-treated mice (p<0.01). (C) Efficacy of S. typhimurium A1-R on survival of nude mice with 4T1-RFP breast cancer brain metastasis formed from orthotopic implantation and primary tumor resection. Survival of the S. typhimurium A1-R-treated animals was prolonged as shown by Kaplan Meier curves (p=0.005)