Folate deficiency affects mammary gland development in pre‐ and peri‐pubescent mice (827.12)

Abstract

The ducts of mammary glands (MG) undergo phases of isometric and allometric growth during postnatal life. Folate is required for DNA synthesis and stability, where its effects are modulated by estrogen. Here we investigated the effects of folate deficiency on early MG development. Female FVB mice were assigned to either a control (2 mg folic acid/kg) or deficient (0 mg folic acid/kg) amino acid defined diet during in utero, postnatal, and early pubertal development. Tissues were assessed at weaning and during the peri‐pubescent period. The area occupied by the mammary ducts was reduced in folate deficient animals at weaning and during early puberty (p<0.0001). The slope of MG growth in the isometric phase, from birth to weaning, was less for the MG of deficient females compared with controls (95% confidence limits 0.23‐0.78 and 1.47‐1.82, respectively). Allometric growth was unaffected by diet. We conclude that folate deficiency impairs ductal elongation in the MGs of female mice prior to puberty. Alterations in pre‐pubertal development may fundamentally alter MG physiology throughout life, with potential impacts on lactation potential and risk of breast cancer.Grant Funding Source: Supported by California Breast Cancer Research Program