A Novel Approach to the Nutrigenetics and Nutrigenomics of Breast Cancer

Breast cancer is the major cause of cancer death in women worldwide. However, several epidemiological studies have shown that incidence of this cancer is specifically higher in developed than in developing countries (1). Geographic variation, lifestyle habits and diet diversity can justify difference in incidence rate (2). Many of the changes that occur in the DNA methylation patterns like gene-specific promoter hypermethylation or hupomethylation which lead to gene silencing or activation, can be reversed and responsive to environmental factor such as diet (3). In addition to DNA methylation pattern, DNA methyltransferase (DNMTs) that catalyzing methylation reaction of DNA is important target for epigenetic chemoprevention (4). One of the strategies for cancer treatment is the use of DNMT inhibitors such as azacitidine and decitabine. However, the use of these drugs is not without side effects. For this reason using of some bioactive phytochemicals such as sulforphane (SFN) which present in cruciferous vegetables like broccoli, broccoli sprouts, cabbage and kale, especially when are used at low doses and within the range of physiological concentrations, seem to be safe (3, 5, 6). Several in vitro study have been demonstrated that SFN inhibits growth of phenotypically different breast cancer cells (7-9). Some chemoprotective mechanism presented to explain the effect SFN on inhibiting tumor cells growth are the repression of phase 1 detoxification enzymes and the induction of phase 2 enzymes, cell cycle arrest and apoptosis induction as well as inhibition of cell proliferation (3, 7-9). In conclusion, it seems that SFN is novel chemopreventive agent that through indirect modulation of DNA methylation has role in epigenetic therapy of solid tumours along with synthetic drugs.