Fig. 5

Everolimus (EV) inhibits growth of breast cancer bone metastases in vivo. a Female NMRI nude mice received intracardial injections with MDA-MB-231 cells expressing the firefly luciferase gene. Mice received daily treatments of control (nine mice) or 1 mg/kg EV (nine mice), and developing metastases were monitored weekly using the Xenogen IVIS 200 in vivo imaging system until mice were killed on day 36. Of note, one mouse in the control group died early as a result of paralysis on day 34. For this mouse, the measurement on day 28 was included. No animals in the EV treatment group developed paralysis. Representative dorsal-facing images with the observed bioluminescent signal at sites of tumor burden are shown, with animals arranged from left to right according to increasing bioluminescent signals. b The number of lesions per animal with signals ≥1 × 10⁷ photons/s/cm²/sr were counted and compared between the groups, and the results are presented in a box plot. c The average luciferase signal intensity (per second per centimeter squared per steradian) from regions of interest was calculated per metastatic signal focus (EV n = 57 detectable lesions, control n = 90 detectable lesions). d The sites of bioluminescent signal in the knee joint were confirmed by 3D micro-computed tomography (µCT) and corresponded with osteolysis (as indicated by red and white arrowheads). e Bone parameters of the femur where assessed by μCT: bone mineral density (BMD), bone volume over total volume (BV/TV), trabecular number (Tb.N), and trabecular separation (Tb.Sp). Data are shown as mean ± SD and were analyzed using Student’s t test (* p < 0.05, ** p < 0.01, *** p < 0.001). Equal volumes of dimethyl sulfoxide used to prepare and administer EV concentrations were used in all control conditions. HA Hydroxyapatite