Objective      To determine the effects of 3

6-dihydroxyflavone on the growth and microRNAs expression profile in transplanted tumor of human breast cancer MDA-MB-453 cells with over-expressed HER-2/neu.       Methods      Eighteen female BALB/c nude mice were injected with MDA-MB-453 cells to establish transplanted tumor models. The mice were equally randomized into 3 groups including control group

low dose and high dose treatment groups. Oral administration of 3

6-dihydroxyflavone [0

10 and 20 mg/(kg·d) respectively] were given to the corresponding mice in 72 h after transplantation. Tumor volumes and weights were measured every 4 d. Mice were sacrificed after 28 days’ treatment. Total RNA was extracted and miRNAs were isolated. Samples were then linked with biotin-labeled signaling molecules

and were hybridized with miRNAs microarrays.       Results      The growth of transplanted tumors was significantly suppressed in treatment groups. Tumors volume were significantly smaller in high dose group and low dose group than in the control after 12 days’ (P0.05) and 24 days’ treatment (P0.01). The microarray assay showed 12 miRNAs expression in tumors of high dose group were significantly up-regulated

and 15 miRNAs expression were markedly decreased.       Conclusion      3

6-dihydroxyflavone significantly suppresses the growth of transplanted tumor of human breast cancer MDA-MB-453 cells

and affect  microRNAs expression profile.