Objective: To investigate the effects of Aidi Injection on the MicroRNAs (miRNA) expression profiles in human breast cancer cells and explore the potential targets of the cancer treatment.
Methods: MCF-7 breast cancer cells were grown in RPMI 1640 medium supplemented with different concentrations of ADI. The inhibition of cell proliferation was measured by MTT assay. MCF-7 cells were treated by ADI with above 50% inhibiting concentration (IC50) for 48 h. The expression profiles of miRNA in ADI-treated and ADI-untreated MCF-7 cells were detected with miRNA microarray chips and the array data were verified by quantitative RT-PCR. MCF-7 cells were transiently transfected with miRNA mimics by liposome method. Potential mRNA targets were predicted by informatics analysis with TargetScan and PicTar software.
Results: ADI significantly inhibited the proliferation of MCF-7 cells in a dose-dependent manner. The IC50 of ADI was 55.71 mg/mL after treatment for 48 h. The 60 mg/mL ADI was used as the therapeutic drug concentration. Microarray analysis identified 45 miRNAs that were up-regulated and 55 miRNAs that were down-regulated in response to ADI treatment. Many ADI-induced miRNAs were related to breast cancers. The microarray data were validated by qRT-PCR. Ectopic expression of 100 nmol/L mir-126 mimics significantly inhibited the proliferation of MCF-7 cells. The 12 potential target genes of mir-126 were predicted by both TargetScan and PicTar software.
Conclusions: The miRNA may serve as therapeutic targets, and the modulation of miRNA expression is an important mechanism of ADI inhibiting breast cancer cell growth.