Heterocyclic amines have been shown to cause somatic cell mutations and induce tumors in animal models. Therefore, individuals who consume cooked meats in their daily diets are continually exposed to mutagenic heterocyclic amines. Strategies to control cancer should include primary prevention based on understanding the causes of breast cancer. Although many chemicals can induce breast cancer in experimental animals, heterocyclic amines are the only mammary carcinogens known to be present in everyday diets. Heterocyclic amines, however, require metabolic activation in order to damage DNA, cause mutations, and exert a carcinogenic effect.
Metabolic activation involves multiple enzyme steps that convert the parent compound into a mutagen.
The initiation of mammary cancer could be related to the ability of mammary gland cells to transport and metabolize herteocyclic amines. Dr. Gaubatz's laboratory is working to identify the enzymes responsible for metabolic activation of heterocyclic amines and to characterize carcinogen processing in mammary epithelial cells. These steps will help them to determine toxic effects of heterocyclic amines in target cells, and examine the ability of mammary gland cells to repair their damaged genes. Since human breast cancer cells contain multiple genetic alterations and carcinogenesis requires a number of steps, it is possible that dietary mutagens could play a role in one or more of these processes and thus, contribute to the incidence of human breast cancers. While changes in diet and limiting carcinogen exposure may someday alter breast cancer incidence, chemical intervention offers an attractive approach for more immediate results.