The study referenced above was designed to investigate the mechanism of action by which a common HCA increases breast cancer risk. Cooking of meat produces HCAs, of which 2-amino-1-methyl-6-phenylimidazo|4,5-b|pyridine (PhIP) is the most abundant. PhIP has previously been shown to have DNA damaging and mutagenic activities. In addition, PhIP has been reported to have estrogenic effects that could contribute to breast-specific carcinogenicity.

To conduct the study, the authors examined the effect of treatment with PhIP and the estrogen 17-β-estradiol (E2) on global microRNA (miRNA) expression of hormone receptor positive (ER+/PR+) MCF-7 human breast cancer cells. Both PhIP and E2 caused widespread and largely similar effects on the expression of miRNA. Many of the affected miRNA have been implicated in the development and progression of breast cancer. The authors conclude that PhIP might induce widespread effects by means of the activation of estrogen receptor alpha (ERα). In addition, deregulation of miRNA by PhIP could potentially be an important mechanism in breast cancer promotion that does not involve damage to DNA.

Please see our article on what ER+ breast cancer patients and survivors should eat more information.