Figure 6. Treatment with selamectin inhibits TNBC growth and metastasis in vivo.
A, MMTV-Myc mouse mammary tumor cells were pre-treated in vitro with vehicle or selamectin for 7 days. 200,000 cells were inoculated into the inguinal mammary fat pads of FVB/N mice (n = 10 per arm). Tumor volume (mm3) was calculated on the days indicated (P = 0.0017).
B–D, 50,000 MMTV-Myc cells were inoculated into the flanks of FVB/N mice on day 0 and treated with selamectin (1.6 mg/kg/day) for 15 days (n = 10 mice per arm). Tumor volume (B) (P < 0.0001), tumor mass (C) (P = 0.0161), and number of lung metastases (D) (P = 0.0224) in each group were measured.
E–G, 4T1 cells (10,000 per mouse) were inoculated into the flanks of BALB/c mice. Tumors were allowed to grow for 10 days before surgical removal. Treatment was then initiated with selamectin (3.2 mg/kg/day for 30 days, n = 4) or vehicle (n = 5). Animals were sacrificed after 30 days and the total number of lung metastases were measured (E, F) (P = 0.0017). Also measured were number of metastases according to size in each group (G) (< 1mm, P = 0.0198; 1–2mm, P = 0.0235; > 2mm, P = 0.0447).
Error bars represent mean ± SD. P = 0.0224, unpaired t test.