Amlexanox delays tumour formation in a diet-induced obesity/PyMT-MMTV mouse model.Figure 7A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). Mice were administered amlexanox (17 mM) or vehicle control daily by oral gavage (Reilly et al, 2013). A control group (wild-type mice) was also included to confirm the efficacy of the diet and to control for possible unpredicted interactions of the MMTV-PyMT gene. Schematic representation of combined genetic mouse model of breast cancer and high fat diet-induced obesity used to study the effects of amlexanox in tumour formation. A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). Wild-type mice on HFD gain more weight compared to ND mice. *p < 0.05 by one-tailed students t-test. A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). Average adipocytes size (major diameter) in mammary fat pads is larger in HFD mice compared to ND mice based on the analysis of at least 100 adipocytes per mice on H&E stained sections. *p < 0.05 by two-tailed students t-test. A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). The number of F4/80+ macrophages in mammary fat pads is increased in HFD mice compared to ND mice. The average of F4/80+ macrophages in at least 10 fields of view per mouse is shown. *p < 0.05 by two-tailed students t-test. A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). Mice were administered amlexanox (17 mM) or vehicle control daily by oral gavage (Reilly et al, 2013). A control group (wild-type mice) was also included to confirm the efficacy of the diet and to control for possible unpredicted interactions of the MMTV-PyMT gene. PyMT-MMTV+/- mice on HFD gain more weight compared to ND mice. *p < 0.05 by one-tailed students t-test. Amlexanox does not affect weight gain either in mice on F) ND or G) HFD. A-J)Ten per group female C57Bl/6 mice heterozygous for the PyMT-MMTV started high fat diet (HFD) when 6-7 weeks old (prior of mammary tumour development) together with control mice on normal diet (ND; n=10). Mice were administered amlexanox (17 mM) or vehicle control daily by oral gavage (Reilly et al, 2013). A control group (wild-type mice) was also included to confirm the efficacy of the diet and to control for possible unpredicted interactions of the MMTV-PyMT gene. Mammary tumours are developing earlier in PyMT-MMTV+/- mice on HFD compared to ND mice. Amlexanox does not affect tumour development in PyMT-MMTV+/- mice on ND, but delays tumour formation in J) HFD mice.