Study Of Different Ratios Of Dietary N-6/n-3 PUFA On Occurance And Progression Of Breast Cancer And Relating Mechanism

The relationship between diet, nutrition and tumor development in human being is a matter of concern in many research realms. Evidence from those studies suggests a close link between dietary nutritional factors and occurrence, development and prognosis of tumors. In the last several decades, increasing attention has been paid to the intake of dietary fat and the risk of cancers, which has indicated that dietary fat intake can influence incidence of the epithelium-derived or hormone-related cancers (e.g., breast cancer, prostate cancer and colon cancer). Moreover, different types of fatty acids, including saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), have different effects on the risk of breast cancer. Indeed, it is found that n-6 PUFA can stimulate the growth and development of tumors, whereas n-3 PUFA can inhibit the cells proliferation and exert a protective effect on tumors development, so the effects of PUFA on the breast cancer risk may be more complicated and important than that of other kinds of fatty acids.However, the molecular mechanisms of n-6 PUFA and n-3 PUFA on breast tumorigenesis are far from understood. Simopoulos et al. found that the optimal ratios of dietary n-6/n-3 PUFA might vary with the disease under consideration, but a low ratio of n-6/n-3 PUFA was more desirable in reducing the risk of the chronic diseases such as tumors. Some researches also demonstrated that the ratios of n-6 PUFA to n-3 PUFA, but not absolute concentration of these fatty acids in adipose tissue were to be strongly associated with the risk of breast cancer. Nevertheless, it still remains unclear on determinating an rational ratio of n-6/n-3 PUFA in the diet for preventing breast cancer. To date, the main source of dietary fat in Chinese residents is from sunflower seed oil, soybean oil and corn oil, etc.that are rich in n-6 PUFA but less in n-3 PUFA and leads to a high ratio of n-6/n-3 PUFA in the diet. At the same time, many reports have revealed a trend of the increasing breast cancer incidence in Chinese women, especially in developed areas and some megapolis. Hence, it is very important to explore the molecular mechanisms of different dietary fatty acids and n-6/n-3 PUFA ratios on breast cancer development, and is...