[Effects of different dietary fatty acid on expression of nuclear receptor genes in breast cancer of rats].

Objective: To study the effects of different dietary fatty acid on the expression of nuclear receptor genes in the breast cancer of rats.

Methods: Fifty-day-old female Sprague-Dawley rats were fed on eight different diets containing following fatty acids: saturated fatty acid (SFA); monounsaturated fatty acid (MUFA); n-6 polyunsaturated fatty acid (PUFA); n-3 PUFA; 1:1 n-6/n-3; 5:1 n-6/n-3; 10:1 n-6/n-3; 1:2:1 S/M/P (n-6/n-3 at 1:1). The rats were given a single intraperitoneal injection of methyl-nitrosourea (MNU) at 50 mg/kg body weight to establish the rat model of mammary carcinogenesis, the ultrastructure changes of mammary gland cells in rats were observed by transmission electron microscope, the cell proliferation activity was detected by BrdU-labeled immunocytochemistry, and the expression of PPARbeta and PPARgamma mRNA were assayed by RT-PCR.