Figure 6: Metformin inhibits tumour growth and angiogenesis in diet-induced obese mice.

Mice were treated as in Fig. 1a; except after 9 weeks one group of ND and one group of HFD mice were fed with 0.5% metformin water. (a,b) Average Py8119 tumour volume (a) or body weight (b) ±s.e.m. (n=5 ND+Met, n=10 HFD+Met, n=14 ND, n=24 HFD). Two-way ANOVA was used to determine significance. (c) Representative IHC staining for CD31 from the indicated mice. Scale bar, 200 μm. (d) Quantification of IHC staining in c. Data represent the average area of CD31⁺ staining over total area±s.d. At least three fields per section and three tumours per group were used in the analysis. (e) Average mRNA expression of Vegfa±s.d. in tumours from the indicated mice (n=3). (f) Adipocytes were treated with 100 ng ml⁻¹ rIL-1β and 500 μM metformin as indicated. Data represent the average Vegfa mRNA level relative to Ppia as a fold change compared with non-treated cells±s.d. (n=3). Tumour study was repeated in a different cohort of animals. All other studies represent results from two to three repeats. Group means were compared by Student’s t-test to determine significance.