Figure 3.

Whole-Animal Bioluminescence Imaging of NanoLuc-β₂AR MDA-MB-231^HM Tumor Growth and Metastasis Development

(A) Female BALB/c nu/nu mice (7-week-old) were injected in the fourth left mammary fat pad with 5 × 10⁵ MDA-MB-231^HM triple-negative human breast cancer cells that stably express the NanoLuc-tagged human β₂-adrenoceptor. Tumor development was monitored by bioluminescence imaging (left y axis) 5 min after IV injection of the NanoLuc substrate furimazine (100 μL in PBS, circa 0.37 mg/kg) or by caliper measurements (right y axis) over 35 days.

(B) Representative bioluminescence images of primary tumors.

(C) Bioluminescence monitoring of the development of metastasis in lungs and axillary lymph nodes. Inset: representative images of lung and lymph node metastasis. Data were obtained from 11 mice and are expressed as mean ± SE. *p < 0.05, **p < 0.005, ***p < 0.0001 (two-way ANOVA with Tukey's multiple comparisons with respect to day 8 baseline). For luminescence measurements, the statistical analysis was applied to the log transformed values.