Development of micoRNA expression signatures for invasive ductal breast carcinoma

To further develop gene expression approach to miRNA biomarker discovery, we have employed miRNA microarray expression profiling as a discovery platform to identify miRNA with the potential to regulated the gene expression signatures in the process of tumor development. Human FFPE tissues from grade 1, 2 and 3 were used to profile miRNA. The miRNA targeted genes were also studied for expression along with the selected miRNA, from this signature in the same RNA samples by real-time PCR, confirming the selected miRNA has regulatory action on the target gene expression. miRNA were profiled with less number of samples from each grade using miRNa microarray hybridization. Confirmation of the expression was carried out with more (20 from each grade)number of samples and targetted gene expression regulation was confirmed using RT PCR.