Figure 1.

(A) Primary tumor growth and overt metastasis of 4T1 breast cancer cells, tracked using luminescence, following mammary fat pad injection. Luminescence values (B) steadily increased in the primary tumor for each time point and (C) showed overt pulmonary metastasis occurring between days 20 and 25. Control mice were sacrificed at day 25. (n = 3 mice, mean ± s.d.). (D) Representative H&E, Ki-67, and fibronectin (FN) staining of 5 µm lung sections at each time point. Scale bar is 200 µm. (E) The lungs showed a loss of native structure with an accumulation of tissue density, quantified from H&E staining (n = 6 images, mean ± s.d.). (F) Ki-67 positive cells significantly increased in tumor bearing mice starting at day 15 (n = 6 images, mean ± s.d.). (G) FN levels initially increased but returned to control levels by day 20 (n = 6 images, mean ± s.d.). (* indicates p < 0.05). (H) Cleared whole lobes confirm tissue accumulation. Scale bar is 50 µm.