Obesity and alterations in metabolic programming from early diet exposures can affect the propensity to disease in later life. Through dietary manipulation, developing mouse pups were exposed to a hyperinsulinemic, hyperglycemic milieu during three developmental phases: gestation, lactation, and postweaning. Analyses showed that a postweaning high fat/high sugar (HF/HS) diet had the main negative effect on adult body weight, glucose tolerance, and insulin resistance. However, dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis revealed that animals born to a mother fed a HF/HS gestation diet, nursed by a mother on a mildly diet-restricted, low fat/low sugar diet (DR) and weaned onto a HF/HS diet (HF/DR/HF) had the highest mammary tumor incidence, while HF/HF/DR had the lowest tumor incidence. Cox proportional hazards analysis showed that a HF/HS postweaning diet doubled mammary cancer risk, and a HF/HS diet during gestation and postweaning increased risk 5.5 times. Exposure to a HF/HS diet during gestation, when combined with a postweaning DR diet, had a protective effect, reducing mammary tumor risk by 86% (HR = 0.142). Serum adipocytokine analysis revealed significant diet-dependent differences in leptin/adiponectin ratio and IGF-1. Flow cytometry analysis of cells isolated from mammary glands from a high tumor incidence group, DR/HF/HF, showed a significant increase in the size of the mammary stem cell compartment compared with a low tumor group, HF/HF/DR. These results indicate that dietary reprogramming induces an expansion of the mammary stem cell compartment during mammary development, increasing likely carcinogen targets and mammary cancer risk. Cancer Prev Res; 10(10); 553-62. ©2017 AACRSee related editorial by Freedland, p. 551-2.
©2017 American Association for Cancer Research.