Fig. 1. Intermittent fasting inhibits tumor growth and metastasis via SIRT7.

a–f Immunoblotting and quantification of protein levels in 4T1 murine mammary cancer cells (a, b), MDA-231 (c, d), and MCF-7 human breast cancer cells (e, f) cultured with the indicated doses of glucose for short-term treatment. The relevant quantifications were collected from three independent experiments. g 4T1 cells stably transfected with Scramble (Scram) and Sirt7 knockdown (KD7) shRNAs were injected into the mammary fat pad of female Balb/c mice. Mice in the Scram + F and KD7 + F groups were subjected to intermittent fasting (IF) for 48 h from day 16 and day 22, respectively; otherwise, all animals were fed ad libitum (n = 5 mice in the scramble group and n = 6 in each of the fasting groups). Tumor size was measured using Vernier calipers. h, i Scram and KD7-transfected 4T1 cells were injected into the tail vein of female Balb/c mice on day 0 (arrow) (n = 3 mice in each group). Mice were subjected to IF as indicated; otherwise, animals were fed ad libitum. Lung metastatic tumor nodules were analyzed by H&E staining (h) and the number of nodules was counted in the whole lung (i). j Immunohistochemistry (IHC) staining showing the levels of SIRT7, (pS473)AKT, and (pS9)GSK3β in tumor samples of Fig. 1g. Scale bar, 50 µm. Data represent means ± SEM (b, d, f, g, i). P values were calculated by two-tailed Student’s t-test (b, d, f, i) or two-way ANOVA analysis (g), *P = 0.03, ***P = 0.0000002. Representative results were obtained from at least three independent experiments. Source data are provided as a Source Data file.