Canola oil inhibits human breast cancer cell growth by regulating caspase‐3 and p53

Abstract

Epidemiological studies indicate that consuming a high‐fat diet may be correlated with an increased risk of breast cancer in women. However, increasing evidence suggests that it is not the quantity of fat but the type of fat intake that influences breast cancer risk. It is also suggested that the protective effect of omega‐3 fatty acids on breast cancer risk depends on the level of omega‐6 fatty acids, with a recommended omega‐6 to omega‐3 fatty acids ratio at 2:1 or lower. Canola oil has one of the lowest levels of saturated fat (7%, about half the level present in corn oil, olive oil and soybean oil). It has a relatively high level of oleic acid (monounsaturated fatty acid, 62%) and omega‐3 fatty acids (alpha‐linolenic, 10%) compared to most vegetable oils. It is thought that the low saturated fat, high oleic acid, and relatively high omega‐3 fatty acids content in canola oil give it particularly healthful properties. To investigate the effects of canola oil on breast cancer cell growth and apoptosis, two estrogen receptor‐positive breast cancer cell lines, T47D and MCF‐7, as well as a normal mammary cell line, MCF‐10A, were cultured and cell proliferation, caspase‐3 and p53 activities were measured. Canola oil supplementation significantly inhibited the growth of both T47D and MCF‐7 cell lines, but not MCF10A cell line. Canola oil also significantly increased the expression of p53, a tumor suppressor gene involved in cancer cell death, as well as the activity of caspase‐3 enzyme, one of the crucial enzymes regulating apoptosis pathway. Dietary strategies for cancer prevention and therapy are low‐risk and cost‐effective. Therefore, these results could be useful in the development of improved nutritional strategies for breast cancer prevention and therapy to reduce breast cancer risk. Supported by USDA‐CSREES (#2007‐38624‐18602).