Long-term genistein treatment of MCF-7 cells decreases acetylated histone 3 expression and alters growth responses to mitogens and histone deacetylase inhibitors.

Defects in epigenetic regulation of gene transcription play an important role in carcinogenesis of the breast and other tissues. The two most widely studied epigenetic changes are DNA methylation and acetylation of histone proteins and inhibition of these processes inhibits growth in breast cancer cell lines. These data coupled with the evidence that fetal and neonatal exposure to oestrogenic substances may lead to epigenetic changes that predispose or protect against the development of breast cancer in later life formed the basis for this study.