Effect of Simvastatin on C-Myc, Cyclin D1 and P53 Expression in Dmba-Induced Breast Cancer in Mice

Introduction: recently, the therapeutic and antioxidant effects of simvastatin on 7,12-dimethylbenz[a] anthracene (dmba) induced breast cancer have been studied. to gain further understanding of the molecular mechanisms of simvastatin, this study investigated its effects on the expression of c-myc, cyclin d1 and p53 in normal mammary glands and tumors. methods: female albino mice were divided into two groups: 1) n group, healthy mice without dmba and 2) d group, mice with dmba administration. after the appearance of tumors, d group mice are subdivided into 3 groups, as control (c), simvastatin- treated group (s) which received 80 mg/kg/day, orally and tamoxifen-treated group (t) with 50 mg/kg/day, orally. after 4 weeks, animals were sacrificed. also, the tumors and normal mammary glands were removed for histopathological evaluations and analysis of gene expression by qrt-pcr. results: the results showed the up-regulation of c-myc and cyclin d1 in tumors of the control group compared with mammary glands of the n group. similar to tamoxifen, the simvastatin treatment could normalize the expression of c-myc and cyclin d1; however, the expression of p53 did not change in the treated groups. conclusion: down-regulation of c-myc and cyclin d1 in treated tumors with simvastatin could be a possible molecular mechanism for its therapeutic effects in dmba-induced breast cancer in mice.