Dietary canola oil and growth of implanted drug‐resistant MCF‐7 human breast cancer in Balb/c nude mice

Abstract

The objective of the project was to determine the extent to which dietary canola oil (CAN) increases susceptibility of drug resistant human breast cancer cells to treatment. Treatment of doxorubicin (DOX)‐resistant MCF‐7 breast cancer cells in vitro with DOX plus CAN significantly suppressed cell proliferation as compared to the control, DOX, or CAN‐treated cells. To determine the effect of CAN on tumor growth and sensitivity to treatment in vivo, nude mice were fed either a soybean oil‐containing diet (SOY) or CAN diet and then implanted with DOX‐resistant human breast cancer cells to grow cancer. The CAN diet reduced tumor growth and also improved the tumor growth inhibitory effect of DOX on drug‐resistant cancer cells. Using qPCR, we observed that mRNA expression of both the P‐glycoprotein‐encoding multidrug resistant 1 gene and the mouse double minute 2 gene in tumor tissues were reduced by the CAN diet. Our findings suggest that a CAN diet inhibits tumor growth and sensitizes drug‐resistant breast cancer cells to treatment, due in part to alteration of gene expression. Overall, these novel findings advance the understanding of the role of dietary fat in breast cancer treatment, and future studies aimed at elucidating the detailed mechanism through which CAN affects drug resistant cancer cells are warranted. Research was funded by United States Department of Agriculture‐ National Institute of Food and Agriculture.Grant Funding Source : USDA‐NIFA