Fig. 2

SIRT7 inhibits breast cancer lung metastasis. a Immunoblots showing Sirt7 level in 4T1 cells expressing shSirt7. b Representative photos of murine lung sections showing metastatic nodules (hematoxylin & eosin staining) (H&E) and Sirt7 expression (left). Dotted lines indicate the metastatic lesions. Scale bar, 1 cm (H&E staining) and 100 μm (IHC). Metastatic incidence and number of nodules were summarized (right, n = 6 for each group). c Representative images of lung (upper) and H&E-stained lung sections (lower) showing spontaneous metastases generated from 4T1 cells after mammary fat pad injection. Dotted lines indicate metastatic lesions. Scale bar, 1 cm (upper) and 500 μm (lower). d Scatter plot showing lung metastatic nodules (n = 7 for each group). e Scatter plot showing the wet weight of lungs in c. f Immunoblots of SIRT7 in control (empty vector, EV) and SIRT7-overexpressing MDA-MB-231 cells (OESIRT7). g Representative H&E-stained lung sections. Dotted lines highlight the metastatic lesions. Scale bar, 500 μm. h Scatter plot showing lung metastatic nodules from animals injected with EV or OESIRT7 cells (n = 13 and 10, respectively). i Representative images of lung (left) and H&E-stained lung sections (right) from spontaneous metastases generated in PyMT or PyMT; Sirt7 ^tg mice after doxycycline feeding. Scale bar, 2 cm. j Representative IHC staining of Sirt7 in lungs of PyMT or PyMT; Sirt7 ^tg mice after doxycycline feeding. Scale bar, 100 μm. k Scatter plot showing the lung metastatic nodules from control (n = 7) or PyMT; Sirt7 ^tg mice (n = 7). *P < 0.05, **P < 0.01. P-values were obtained by non-parametric Mann–Whitney U-test d, h, k or Student’s t-test e. Data are shown as mean ± S.E.M. and representative of two independent experiments